Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2016	Feb. 03, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Trading Symbol	MD
Entity Registrant Name	MEDNAX, INC.
Entity Central Index Key	0000893949
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		93,793,665
Entity Public Float			$ 6,630,916,089

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 55,698	$ 51,572
Short-term investments	11,286	8,853
Accounts receivable, net	495,276	444,737
Prepaid expenses	11,051	9,639
Other assets	13,817	12,968
Total current assets	587,128	527,769
Investments	78,975	63,288
Property and equipment, net	103,068	83,634
Goodwill	3,845,157	3,366,150
Intangible assets, net	668,529	424,219
Other assets	56,543	82,154
Total assets	5,339,400	4,547,214
Current liabilities:
Accounts payable and accrued expenses	407,938	395,807
Current portion of long-term debt and capital lease obligations	22,054	11,883
Income taxes payable	18,957	21,081
Total current liabilities	448,949	428,771
Line of credit	783,500	343,500
Long-term debt and capital lease obligations, net	900,128	919,320
Long-term professional liabilities	173,080	176,532
Deferred income taxes	227,802	188,956
Other liabilities	45,174	52,289
Total liabilities	2,578,633	2,109,368
Commitments and contingencies
Shareholders' equity:
Preferred stock; $.01 par value; 1,000 shares authorized; none issued
Common stock; $.01 par value; 200,000 shares authorized; 93,718 and 93,739 shares issued and outstanding, respectively	937	937
Additional paid-in capital	974,304	926,235
Retained earnings	1,785,526	1,510,356
Total MEDNAX, Inc. shareholders' equity	2,760,767	2,437,528
Noncontrolling interests		318
Total equity	2,760,767	2,437,846
Total liabilities and equity	$ 5,339,400	$ 4,547,214

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	93,718,000	93,739,000
Common stock, shares outstanding	93,718,000	93,739,000

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net revenue	$ 830,770	$ 828,006	$ 771,759	$ 752,624	$ 741,740	$ 722,273	$ 676,588	$ 639,395	$ 3,183,159	$ 2,779,996	$ 2,438,913
Operating expenses:
Practice salaries and benefits	532,952	521,832	484,625	491,811	461,074	450,033	422,803	419,595	2,031,220	1,753,505	1,543,395
Practice supplies and other operating expenses	32,737	31,641	26,992	27,046	26,164	24,007	24,878	23,431	118,416	98,480	89,002
General and administrative expenses	97,049	93,457	92,116	89,950	85,393	80,185	72,401	67,936	372,572	305,915	247,527
Depreciation and amortization	25,254	24,185	20,241	19,584	18,149	16,918	15,549	13,612	89,264	64,228	45,990
Total operating expenses	687,992	671,115	623,974	628,391	590,780	571,143	535,631	524,574	2,611,472	2,222,128	1,925,914
Income from operations	142,778	156,891	147,785	124,233	150,960	151,130	140,957	114,821	571,687	557,868	512,999
Investment and other income	770	221	410	618	751	567	384	142	2,019	1,844	2,728
Interest expense	(16,356)	(17,215)	(15,058)	(14,463)	(8,493)	(6,201)	(5,149)	(3,267)	(63,092)	(23,110)	(8,891)
Equity in earnings of unconsolidated affiliate	806	796	789	794	777	784	745	821	3,185	3,127	1,780
Total non-operating expenses	(14,780)	(16,198)	(13,859)	(13,051)	(6,965)	(4,850)	(4,020)	(2,304)	(57,888)	(18,139)	(4,383)
Income before income taxes	127,998	140,693	133,926	111,182	143,995	146,280	136,937	112,517	513,799	539,729	508,616
Income tax provision	49,919	44,272	51,601	43,411	51,581	55,640	52,889	43,928	189,203	204,038	191,413
Net income	78,079	96,421	82,325	67,771	92,414	90,640	84,048	68,589	324,596	335,691	317,203
Net loss attributable to noncontrolling interests		88	102	128	288	141	82	118	318	629	78
Net income attributable to MEDNAX, Inc.	$ 78,079	$ 96,509	$ 82,427	$ 67,899	$ 92,702	$ 90,781	$ 84,130	$ 68,707	$ 324,914	$ 336,320	$ 317,281
Net income attributable to MEDNAX, Inc.:
Earnings per share, Basic	$ 0.84	$ 1.04	$ 0.89	$ 0.74	$ 1.00	$ 0.98	$ 0.91	$ 0.73	$ 3.52	$ 3.61	$ 3.22
Earnings per share, Diluted	$ 0.84	$ 1.04	$ 0.89	$ 0.73	$ 0.99	$ 0.97	$ 0.90	$ 0.72	$ 3.49	$ 3.58	$ 3.18
Weighted average common shares:
Basic	92,728	92,604	92,182	92,269	92,790	92,949	92,500	94,231	92,422	93,077	98,588
Diluted	93,347	93,146	92,945	93,091	93,536	93,646	93,495	95,325	93,109	93,960	99,887

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2013	$ 2,342,988	$ 1,012	$ 857,953	$ 1,484,023
Balance, Shares at Dec. 31, 2013		101,207
Contributions from noncontrolling interests	1,025				$ 1,025
Net income (loss)	317,203				(78)
Net income (loss)	317,281			317,281
Common stock issued under employee stock option and employee stock purchase plan	42,876	$ 13	42,863
Common stock issued under employee stock option and employee stock purchase plan, shares		1,412
Issuance of restricted stock and vesting of deferred stock		$ 6	(6)
Issuance of restricted stock and vesting of deferred stock, shares		573
Issuance of restricted stock for contingent consideration	705		705
Issuance of restricted stock for contingent consideration, shares		12
Stock-based compensation expense	31,719		31,719
Forfeitures of restricted stock, shares		(34)
Repurchased common stock	(488,429)	$ (71)	(63,836)	(424,522)
Repurchased common stock, shares		(7,140)
Excess tax benefit related to employee stock incentive plans	17,479		17,479
Balance at Dec. 31, 2014	2,265,566	$ 960	886,877	1,376,782	947
Balance, Shares at Dec. 31, 2014		96,030
Net income (loss)	335,691				(629)
Net income (loss)	336,320			336,320
Common stock issued under employee stock option and employee stock purchase plan	20,128	$ 5	20,123
Common stock issued under employee stock option and employee stock purchase plan, shares		463
Issuance of restricted stock and vesting of deferred stock		$ 5	(5)
Issuance of restricted stock and vesting of deferred stock, shares		527
Issuance of restricted stock for acquisition consideration	7,800	$ 1	7,799
Issuance of restricted stock for acquisition consideration, shares		114
Stock-based compensation expense	32,129		32,129
Forfeitures of restricted stock, shares		(30)
Repurchased common stock	$ (235,051)	$ (34)	(32,271)	(202,746)
Repurchased common stock, shares	(3,400)	(3,365)
Excess tax benefit related to employee stock incentive plans	$ 11,583		11,583
Balance at Dec. 31, 2015	2,437,846	$ 937	926,235	1,510,356	318
Balance, Shares at Dec. 31, 2015		93,739
Net income (loss)	324,596				$ (318)
Net income (loss)	324,914			324,914
Common stock issued under employee stock option and employee stock purchase plan	22,022	$ 5	22,017
Common stock issued under employee stock option and employee stock purchase plan, shares		473
Issuance of restricted stock		$ 5	(5)
Issuance of restricted stock, shares		505
Stock-based compensation expense	34,000		34,000
Forfeitures of restricted stock		$ (1)	1
Forfeitures of restricted stock, shares		(53)
Repurchased common stock	$ (61,828)	$ (9)	(12,075)	(49,744)
Repurchased common stock, shares	(900)	(946)
Excess tax benefit related to employee stock incentive plans	$ 4,131		4,131
Balance at Dec. 31, 2016	$ 2,760,767	$ 937	$ 974,304	$ 1,785,526
Balance, Shares at Dec. 31, 2016		93,718

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 324,596	$ 335,691	$ 317,203
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation and amortization	89,264	64,228	45,990
Amortization of premiums, discounts and issuance costs	4,816	1,541	1,230
Net change in fair value of contingent consideration liabilities	772	13	(417)
Stock-based compensation expense	34,000	32,129	31,719
Equity in earnings of unconsolidated affiliate	(3,185)	(3,127)	(1,780)
Distribution of earnings from unconsolidated affiliate	2,625	2,062
Deferred income taxes	18,149	14,494	2,559
Changes in assets and liabilities:
Accounts receivable	(34,000)	(55,391)	(57,018)
Prepaid expenses and other current assets	(783)	(4,905)	1,506
Other long-term assets	10,035	98	907
Accounts payable and accrued expenses	11,617	(7,874)	66,039
Income taxes payable	(2,234)	(4,101)	6,998
Payments of contingent consideration liabilities	(1,037)	(1,439)	(4,071)
Long-term professional liabilities	(3,452)	(2,064)	9,284
Other liabilities	(7,405)	(2,654)	2,492
Net cash provided from operating activities	443,778	368,701	422,641
Cash flows from investing activities:
Acquisition payments, net of cash acquired	(762,302)	(818,903)	(479,394)
Purchases of investments	(60,976)	(33,980)	(26,884)
Proceeds from maturities of investments	41,325	31,956	20,735
Purchases of property and equipment	(39,264)	(27,073)	(18,061)
Net cash used in investing activities	(821,217)	(848,000)	(503,604)
Cash flows from financing activities:
Borrowings on credit agreement	1,940,000	2,121,500	1,754,500
Payments on credit agreement	(1,510,000)	(2,156,000)	(1,213,500)
Proceeds from issuance of senior notes		750,000
Payments for financing costs		(14,190)	(4,281)
Payments of contingent consideration liabilities	(10,740)	(12,856)	(11,740)
Payments on capital lease obligations	(2,130)	(2,171)	(159)
Excess tax benefit from exercises of stock options and vesting of restricted and deferred stock	4,241	11,583	17,462
Proceeds from issuance of common stock	22,022	20,128	42,876
Contribution from noncontrolling interests			1,025
Repurchases of common stock	(61,828)	(235,051)	(488,429)
Net cash provided from financing activities	381,565	482,943	97,754
Net increase in cash and cash equivalents	4,126	3,644	16,791
Cash and cash equivalents at beginning of year	51,572	47,928	31,137
Cash and cash equivalents at end of year	55,698	51,572	47,928
Supplemental disclosure of cash flow information:
Interest	60,453	20,367	7,323
Income taxes	175,962	181,005	161,841
Non-cash investing and financing activities:
Value of common stock issued for an acquisition		7,800
Equipment financed through capital leases	1,619	3,135	$ 1,244
Property and equipment included in accounts payable	$ 2,673	$ 1,800

General	12 Months Ended
General	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	1. General: The principal business activity of MEDNAX, Inc. (“MEDNAX” or the “Company”) and its subsidiaries is to provide neonatal, anesthesia, maternal-fetal and other pediatric subspecialties physician services. The Company has contracts with affiliated business corporations or professional associations, limited liability companies and partnerships (“affiliated professional contractors”), which are separate legal entities that provide physician services in certain states and Puerto Rico. The Company and its affiliated professional contractors also have contracts with hospitals and other healthcare facilities to provide physician services, which include (i) fee-for-service contracts, whereby hospitals agree, in exchange for the Company’s services, to authorize the Company and its healthcare professionals to bill and collect the charges for medical services rendered by the Company’s affiliated healthcare professionals, and (ii) administrative fee contracts, whereby the Company is assured a minimum revenue level. MEDNAX also provides teleradiology services to hospital, health system and radiology group facilities in all 50 states, the District of Columbia and Puerto Rico through a network of affiliated radiologists. In addition to its national physician network, the Company also provides services nationwide to healthcare providers, including its own, through complementary businesses including a management services organization specializing in full-service revenue cycle management and a consulting services company.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies:

Principles of Presentation

The consolidated financial statements include all the accounts of the Company and its subsidiaries combined with the accounts of the affiliated professional contractors with which the Company currently has specific management arrangements. The Company’s agreements with affiliated professional contractors provide that the term of the arrangements are in most cases permanent, subject only to termination by the Company, except in the case of gross negligence, fraud or bankruptcy of the Company. The Company has the right to receive income, both as ongoing fees and as proceeds from the sale of its interest in the Company’s affiliated professional contractors, in an amount that fluctuates based on the performance of the affiliated professional contractors and the change in the fair value of the Company’s interest in the affiliated professional contractors. The Company has exclusive responsibility for the provision of all non-medical services required for the day-to-day operation and management of the Company’s affiliated professional contractors and establishes the guidelines for the employment and compensation of the physicians. In addition, the agreements provide that the Company has the right, but not the obligation, to purchase, or to designate a person(s) to purchase, the stock of the Company’s affiliated professional contractors for a nominal amount. Separately, in its sole discretion, the Company has the right to assign its interest in the agreements. Based upon the provisions of these agreements, the Company has determined that the affiliated professional contractors are variable interest entities and that the Company is the primary beneficiary as defined in the accounting guidance for consolidation. All significant intercompany and interaffiliate accounts and transactions have been eliminated.

The Company is a partner in a joint venture in which it owns a 75% economic interest. The Company has a management agreement with the joint venture and, based on the terms of the agreement, the Company has determined that the joint venture is a variable interest entity for which the Company is the primary beneficiary as defined in the accounting guidance for consolidation. Accordingly, the financial results of the joint venture are fully consolidated into the Company’s operating results. The equity interests of the outside investor in the equity and results of operations of this consolidated entity are accounted for and presented as noncontrolling interests. In addition, the Company is a partner in a second joint venture in which it owns a 37.5% economic interest. The Company accounts for this joint venture under the equity method of accounting because the Company exercises significant influence over, but does not control, this entity.

Recently Adopted Accounting Pronouncements

In September 2015, the accounting guidance related to business combinations was amended to require that adjustments to provisional amounts that are identified during the measurement period be recognized in the reporting period in which the adjustment amounts are determined rather than being retrospectively recognized as of the acquisition date. Such amounts will be required to either be presented separately on the face of the income statement or within a footnote disclosure stating what the impacts on prior period financial statements would have been had such amounts been recognized as of the acquisition date. This guidance became effective for the Company on January 1, 2016. The adoption of this guidance did not have an impact on the Company’s Consolidated Financial Statements.

In February 2015, the accounting guidance related to consolidation was amended to include changes to both the variable and voting interest models used by companies to evaluate whether an entity should be consolidated. This guidance became effective for the Company on January 1, 2016. The adoption of this guidance did not have an impact on the Company’s Consolidated Financial Statements.

New Accounting Pronouncements

In January 2017, the accounting guidance related to goodwill impairment was amended to remove step two of the impairment test that requires a hypothetical purchase price allocation in order to measure the amount of any impairment. Under the new guidance, only a single-step quantitative test is required and any goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value. The new guidance does not amend the optional alternative to perform a qualitative assessment to determine if a quantitative goodwill impairment test is necessary. This guidance will become effective for the Company on January 1, 2020, with early adoption permitted. The Company does not believe the adoption of this guidance will have an impact on its Consolidated Financial Statements.

In January 2017, the accounting guidance related to business combinations was amended to clarify the definition of a business. This guidance will become effective for the Company on January 1, 2018, with early adoption permitted. The Company does not believe the adoption of this guidance will have an impact on its Consolidated Financial Statements.

In August 2016, the accounting guidance related to the statement of cash flows was amended with the intent of reducing diversity in practice as to the classification of certain transactions in the statement of cash flows. This guidance will become effective for the Company on January 1, 2018, with early adoption permitted. The Company does not believe the adoption of this guidance will have a material impact on its Consolidated Financial Statements.

In March 2016, the accounting guidance related to various aspects of share-based payment transactions was amended, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Under the new guidance, excess tax benefits and deficiencies are to be recognized as income tax expense or benefit in the income statement as discrete items in the reporting period in which they occur instead of an increase or decrease to shareholders’ equity. An entity should also recognize excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. Excess tax benefits should be classified along with other income tax cash flows as an operating activity. With regard to forfeitures, the entity may make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. This guidance will become effective for the Company on January 1, 2017, with early adoption permitted. The Company expects that the adoption of this guidance will have an impact on its Consolidated Financial Statements, however, the impact will be dependent upon future prices of the Company’s common stock and stock-based compensation exercise and vesting activity and therefore cannot be determined.

In February 2016, accounting guidance related to leases was issued that will require an entity to recognize leased assets and the rights and obligations created by those leased assets on the balance sheet and to disclose key information about the entity’s leasing arrangements. This guidance will become effective for the Company on January 1, 2019, with early adoption permitted upon issuance of the guidance. The Company expects that the adoption of this guidance will have a material impact on its Consolidated Balance Sheets and related disclosures, resulting from the recognition of significant right of use assets and related liabilities primarily related to its operating lease arrangements for space in hospitals and certain other facilities for its business and medical offices. The Company’s evaluation of this guidance and its impacts will continue into 2017.

In May 2014, the accounting guidance related to revenue recognition was amended to outline a single, comprehensive model for accounting for revenue from contracts with customers. The new guidance will become effective for the Company on January 1, 2018, with early adoption permitted on January 1, 2017. The Company’s current revenue recognition policies for its significant revenue streams materially comply with the amended guidance, therefore, the Company does not believe the adoption of this guidance will have a material impact on its Consolidated Financial Statements. The Company’s evaluation of the impact the adoption of this guidance will have on its Consolidated Financial Statements will continue into 2017.

Accounting Estimates and Assumptions

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and assumptions are involved in the calculation of the Company’s allowance for contractual adjustments and uncollectibles on accounts receivable, liabilities for self-insured amounts and claims incurred but not reported related to the Company’s professional liability risks, the fair value of goodwill, and liabilities for uncertain tax positions. Actual results could differ from those estimates.

Segment Reporting

The results of the Company’s operations are aggregated into a single reportable segment for purposes of presenting financial information in accordance with the accounting guidance for segment reporting.

The following table summarizes the Company’s net revenue by service line (in percentages):


	Years Ended December 31,
	2016			2015			2014
Neonatology and other pediatric subspecialties		39	%		44	%		50	%
Anesthesiology		39	%		37	%		36	%
Maternal-fetal medicine		8	%		9	%		9	%
Radiology		6	%		4	%		—
Management services		5	%		2	%		1	%
Pediatric cardiology		3	%		4	%		4	%

		100	%		100	%		100	%

Revenue Recognition

Patient service revenue is recognized at the time services are provided by the Company’s affiliated physicians. Almost all of the Company’s patient service revenue is reimbursed by government-sponsored healthcare programs and third-party insurance payors. Payments for services rendered to the Company’s patients are generally less than billed charges. The Company monitors its revenue and receivables from these sources and records an estimated contractual allowance to properly account for the anticipated differences between billed and reimbursed amounts.

Accordingly, patient service revenue is presented net of an estimated provision for contractual adjustments and uncollectibles. The Company estimates allowances for contractual adjustments and uncollectibles on accounts receivable based upon historical experience and other factors, including days sales outstanding (“DSO”) for accounts receivable, evaluation of expected adjustments and delinquency rates, past adjustments and collection experience in relation to amounts billed, an aging of accounts receivable, current contract and reimbursement terms, changes in payor mix and other relevant information. Contractual adjustments result from the difference between the physician rates for services performed and the reimbursements by government-sponsored healthcare programs and insurance companies for such services.

In addition, the Company generates revenue for services rendered under various coding and billing contracts. Contract terms are specific to each customer and may include a combination of a flat fee for coding of medical charts, a fixed fee per patient visit as well as a percentage of cash collections received by the providers. Revenue for flat and fixed fee arrangements is recognized in the month the coding occurs or the patient visit occurs. Revenue for percentage fees are recognized in the month that cash is collected for customers from payors. Revenue recorded for these services during 2016 were immaterial.

Accounts receivable are primarily amounts due under fee-for-service contracts from third-party payors, such as insurance companies, self-insured employers and patients and government-sponsored healthcare programs geographically dispersed throughout the United States and its territories. Concentration of credit risk relating to accounts receivable is limited by the number, diversity and geographic dispersion of the business units managed by the Company, as well as by the large number of patients and payors, including the various governmental agencies in the states in which the Company provides services. Receivables from government agencies made up approximately 17% and 19% of net accounts receivable at December 31, 2016 and 2015, respectively.

Cash and Cash Equivalents

Cash equivalents are defined as all highly liquid financial instruments with maturities of 90 days or less from the date of purchase. The Company’s cash equivalents typically consist of demand deposits, amounts on deposit in money market accounts, and funds invested in overnight repurchase agreements. Cash equivalent balances may, at certain times, exceed federally insured limits.

Certain cash equivalents carried by the Company are subject to the fair value provisions of the accounting guidance for fair value measurements. See “Fair Value Measurements” below.

Investments

Investments consist of municipal debt securities, federal home loan securities and certificates of deposit. Investments with remaining maturities of less than one year are classified as short-term investments. Investments classified as long-term have maturities of one year to seven years.

The Company intends and has the ability to hold its held-to-maturity securities to maturity, and therefore carries such investments at amortized cost in accordance with the provisions of the accounting guidance for investments in debt securities.

Property and Equipment

Property and equipment are recorded at original purchase cost. Depreciation of property and equipment is computed using the straight-line method over the estimated useful lives of the underlying assets. Estimated useful lives are generally 20 years for buildings; three to seven years for medical equipment, computer equipment, software and furniture; and the lesser of the useful life or the remaining lease term for leasehold improvements and capital leases. Upon sale or retirement of property and equipment, the related cost and accumulated depreciation are eliminated from the respective accounts and any resulting gain or loss is included in earnings.

Business Acquisitions

The Company accounts for all business acquisitions at fair value and expenses acquisition costs as they are incurred. Any identifiable assets acquired and liabilities assumed are recognized and measured at their respective fair values on the acquisition date. If information about facts and circumstances existing as of the acquisition date is incomplete at the end of the reporting period in which a business acquisition occurs, the Company will report provisional amounts for the items for which the accounting is incomplete. The measurement period ends once the Company receives sufficient information to finalize the fair values; however, the period will not exceed one year from the acquisition date. Prior to January 1, 2016, any material adjustments recognized during the measurement period were required to be reflected retrospectively in the Consolidated Financial Statements of the subsequent period. Beginning on January 1, 2016, any adjustments to provisional amounts that are identified during the measurement period are required to be recognized in the reporting period in which the adjustment amounts are determined.

In connection with certain acquisitions, the Company enters into agreements to pay additional amounts in cash or common stock based on the achievement of certain performance measures for up to five years ending after the acquisition dates. The Company measures this contingent consideration at fair value at the acquisition date and records such contingent consideration as a liability or equity on the Company’s Consolidated Balance Sheets on the acquisition date. The fair value of each contingent consideration liability is remeasured at each reporting period with any change in fair value recognized as income or expense within operations in the Company’s Consolidated Statements of Income. See Note 6 for more information on the Company’s business acquisitions.

Goodwill and Other Intangible Assets

The Company records acquired assets and assumed liabilities at their respective fair values under the acquisition method of accounting. Goodwill represents the excess of cost over the fair value of the net assets acquired. Intangible assets with finite lives, principally physician and hospital agreements, customer relationships, patented technology and trade names, are recognized apart from goodwill at the time of acquisition based on the contractual-legal and separability criteria established in the accounting guidance. Intangible assets with finite lives are amortized on either an accelerated basis based on the annual undiscounted economic cash flows associated with the particular intangible asset or on a straight-line basis over their estimated useful lives. Intangible assets with finite lives are amortized over periods of one to 20 years.

Goodwill is tested for impairment at a reporting unit level on at least an annual basis in accordance with the subsequent measurement provisions of the accounting guidance for goodwill. The Company defines a reporting unit based upon its management structure for services provided in specific regions of the United States. The testing for impairment is completed using a two-step test. The first step compares the fair value of a reporting unit with its carrying amount, including goodwill. If the carrying amount of a reporting unit exceeds its fair value, a second step is performed to determine the amount of any impairment loss. The Company uses income and market-based valuation approaches to determine the fair value of its reporting units. These approaches focus on discounted cash flows and market multiples based on the Company’s market capitalization to derive the fair value of a reporting unit. The Company also considers the economic outlook for the healthcare services industry and various other factors during the testing process, including hospital and physician contract changes, local market developments, changes in third-party payor payments, and other publicly available information. The Company completed annual impairment tests in the third quarter of each of 2016, 2015 and 2014 and determined that goodwill was not impaired in any of the three years.

Long-Lived Assets

The Company is required to evaluate long-lived assets, including intangible assets subject to amortization, whenever events or changes in circumstances indicate that the carrying value of the assets may not be fully recoverable. The recoverability of such assets is measured by a comparison of the carrying value of the assets to the future undiscounted cash flows before interest charges to be generated by the assets. If long-lived assets are impaired, the impairment to be recognized is measured as the excess of the carrying value over the fair value. Long-lived assets held for disposal are reported at the lower of the carrying value or fair value less disposal costs. The Company does not believe there are any indicators that would require an adjustment to such assets or their estimated periods of recovery at December 31, 2016 pursuant to current accounting standards.

Common Stock Repurchases

The Company repurchases shares of its common stock as authorized from time to time by its Board of Directors. The Company treats repurchased shares of its common stock as retired as any repurchased shares become authorized but unissued shares. The reacquisition cost of repurchased shares is recorded as a reduction in the respective components of shareholders’ equity.

Professional Liability Coverage

The Company maintains professional liability insurance policies with third-party insurers generally on a claims-made basis, subject to deductibles or self-insured retention, exclusions and other restrictions. The Company’s self-insured retention under its professional liability insurance program is maintained primarily through a wholly owned captive insurance subsidiary. The Company records an estimate of liabilities for self-insured amounts and claims incurred but not reported based on an actuarial valuation using historical loss information, claim emergence patterns and various actuarial assumptions. Liabilities for claims incurred but not reported are not discounted.

Income Taxes

The Company records deferred income taxes using the liability method, whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. If it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is provided against such deferred tax assets. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations.

The accounting guidance for uncertain tax positions prescribes a recognition threshold and measurement attribute for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The guidance also requires policy disclosures regarding penalties and interest and extensive disclosures regarding increases and decreases in uncertain tax positions as a result of tax positions taken in a current or prior period, settlements with taxing authorities and any lapse of an applicable statute of limitations. Additional qualitative discussion is required for any tax position that may result in a significant increase or decrease in uncertain tax positions within a 12-month period from the Company’s reporting date.

Stock Incentive Plans

The Company grants stock-based awards consisting primarily of restricted stock to key employees under its Amended and Restated 2008 Incentive Compensation Plan. The Company measures the cost of employee services received in exchange for stock-based awards based on grant-date fair value and allocates the resulting compensation expense over the corresponding requisite service period using the graded vesting attribution method. The Company also performs analyses to estimate forfeitures of stock-based awards on an annual basis and adjusts the estimates as necessary based on the number of awards that ultimately vest.

Net Income Per Common Share

Basic net income per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share is calculated by dividing net income by the weighted average number of common and potential common shares outstanding during the period. Potential common shares consist of outstanding restricted stock and stock options calculated using the treasury stock method. Under the treasury stock method, the Company includes the assumed excess tax benefits related to the potential exercise or vesting of its stock-based awards using the difference between the average market price for the applicable period less the option price, if any, and the fair value of the stock-based award on the date of grant multiplied by the applicable tax rate.

Fair Value Measurements

In accordance with the accounting guidance for fair value measurements and disclosures, the Company carries its money market funds included in cash and cash equivalents at fair value. In accordance with the three-tier fair value hierarchy under this guidance, the Company determined the fair value using quoted market prices, a Level 1 input as defined under the accounting guidance for fair value measurements. At December 31, 2016 and 2015, the Company’s money market funds had a fair value of $12.4 million and $13.9 million, respectively.

The Company also carries the cash surrender value of life insurance related to its deferred compensation arrangements at fair value. The investments underlying the life insurance contracts consist primarily of exchange-traded equity securities and mutual funds with quoted prices in active markets. In accordance with the three-tier fair value hierarchy, the Company determined the fair value using the cash surrender value of the life insurance, a Level 2 input as defined under the accounting guidance for fair value measurements. At December 31, 2016 and 2015, the Company’s cash surrender value of life insurance had a fair value of $15.8 million and $14.5 million, respectively.

In addition, the Company carries its contingent consideration liabilities related to acquisitions at fair value. In accordance with the three-tier fair value hierarchy, the Company determined the fair value of its contingent consideration liabilities using the income approach with assumed discount rates and payment probabilities. The income approach uses Level 3, or unobservable inputs as defined under the accounting guidance for fair value measurements. At December 31, 2016 and 2015, the Company’s contingent consideration liabilities had a fair value of $17.3 million and $24.9 million, respectively. See Note 6 for more information regarding the Company’s contingent consideration liabilities.

The carrying amounts of cash equivalents, short-term investments, accounts receivable and accounts payable and accrued expenses approximate fair value due to the short maturities of the respective instruments. The carrying values of long-term investments, line of credit, variable rate long-term debt and capital lease obligations approximate fair value. If the Company’s investments were measured at fair value, they would be categorized as Level 2 in the fair value hierarchy. If the Company’s line of credit and variable long-term debt were measured at fair value, they would be categorized as Level 2 in the fair value hierarchy. See Note 10 for information regarding the fair value of the Company’s 5.25% senior unsecured notes due 2023 (the “2023 Notes”).

Investments

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Investments

3. Investments:

Investments held are summarized as follows (in thousands):


	December 31, 2016				December 31, 2015
	Short-Term		Long-Term		Short-Term		Long-Term
Municipal debt securities	$	10,306	$	46,513	$	8,608	$	34,858
Federal home loan securities		—		28,747		—		26,715
Certificates of deposit		980		3,715		245		1,715

	$	11,286	$	78,975	$	8,853	$	63,288

Contractual maturities of long-term investments are summarized as follows (in thousands):


	December 31,
	2016		2015
Due after one year through five years	$	70,005	$	60,383
Due after five years through seven years		8,970		2,905

	$	78,975	$	63,288

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Accounts Receivable and Net Revenue

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Accounts Receivable and Net Revenue

4. Accounts Receivable and Net Revenue:

Accounts receivable, net consists of the following (in thousands):


	December 31,
	2016			2015
Gross accounts receivable	$	1,719,642		$	1,574,038
Allowance for contractual adjustments and uncollectibles		(1,224,366	)		(1,129,301	)

	$	495,276		$	444,737

Net revenue consists of the following (in thousands):


	Years Ended December 31,
	2016			2015			2014
Gross revenue	$	10,374,813		$	8,942,957		$	7,662,556
Contractual adjustments and uncollectibles		(7,464,030	)		(6,389,195	)		(5,403,437	)
Hospital contract administrative fees		272,376			226,234			179,794

	$	3,183,159		$	2,779,996		$	2,438,913

Accounts receivable of $495.3 million and $444.7 million at December 31, 2016 and 2015, respectively, consist primarily of amounts due from government-sponsored healthcare programs and third-party insurance payors for services provided by the Company’s affiliated physicians.

Net revenue of $3.2 billion, $2.8 billion and $2.4 billion for the years ended December 31, 2016, 2015 and 2014, respectively, consists primarily of gross billed charges for services provided by the Company’s affiliated physicians less an estimated allowance for contractual adjustments and uncollectibles to properly account for the anticipated differences between gross billed charge amounts and expected reimbursement amounts.

The Company’s contractual adjustments and uncollectibles as a percentage of gross patient service revenue vary slightly each year depending on several factors, including improved managed care contracting, changes in reimbursement from state Medicaid programs and other government-sponsored programs, shifts in the percentage of patient services being reimbursed under government-sponsored programs and annual price increases.

The Company’s annual price increases typically increase contractual adjustments as a percentage of gross patient service revenue. This increase is primarily due to Medicaid, Medicare and other government-sponsored healthcare programs that generally provide for reimbursements on a fee-schedule basis rather than on a gross charge basis. When the Company bills these programs, like other payors, on a gross-charge basis, it also increases its provision for contractual adjustments and uncollectibles by the amount of any price increase, resulting in a higher contractual adjustment percentage.

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Property and Equipment

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property and Equipment

5. Property and Equipment:

Property and equipment consists of the following (in thousands):


	December 31,
	2016			2015
Building	$	26,572		$	26,382
Land		6,683			6,683
Equipment and other		213,521			169,903

		246,776			202,968
Accumulated depreciation		(143,708	)		(119,334	)

	$	103,068		$	83,634

At December 31, 2016 and 2015, property and equipment includes medical and other equipment held under capital leases of $6.2 million and $5.4 million, and related accumulated depreciation of $4.0 million and $2.3 million, respectively. The Company recorded depreciation expense of $29.0 million, $22.2 million and $15.9 million for the years ended December 31, 2016, 2015 and 2014, respectively.

Business Acquisitions

12 Months Ended

Dec. 31, 2016

Business Combinations [Abstract]

Business Acquisitions

6. Business Acquisitions:

During the year ended December 31, 2016, the Company completed 15 acquisitions, of which 13 were physician group practices including eight anesthesiology practices, two other pediatric subspecialty practices, one neonatology practice, one maternal-fetal medicine practice and one pediatric cardiology practice. In addition, the Company acquired a third-party receivables company and a patient engagement software company as additions to its existing management services organization. The total consideration for the 15 acquisitions was $759.6 million, net of $15.0 million cash acquired, of which $756.1 million was paid in cash and $3.5 million was recorded as a contingent consideration liability.

The 13 physician practice acquisitions expand the Company’s national network of physician practices. The Company expects to improve the results of these physician practices through improved managed care contracting, improved collections, identification of growth initiatives, as well as, operating and cost savings based on the significant infrastructure it has developed. The acquisitions of the third-party receivables company and patient engagement software company are expected to further enhance the Company’s service offerings to its hospital and health system partners as part of its management services organization.

The Company’s preliminary allocation of purchase price is as follows (in thousands):


	Third-Party Receivables Acquisition			Other Acquisitions			Total
Current assets	$	17,819		$	200		$	18,019
Property and equipment		5,807			866			6,673
Other noncurrent assets		115			689			804
Goodwill		190,977			299,005			489,982
Other intangible assets		221,870			82,756			304,626
Current liabilities		(5,863	)		(333	)		(6,196	)
Deferred income tax liabilities—long-term		(31,114	)		(22,388	)		(53,502	)
Other long-term liabilities		(829	)		—			(829	)

	$	398,782		$	360,795		$	759,577

The Company recorded provisional estimates for deferred income taxes related to the third-party receivables acquisition. The final income tax acquisition accounting is expected to be completed during the measurement period, and management does not believe any adjustments to the provisional amounts will be material.

The contingent consideration of $3.5 million recorded during the year ended December 31, 2016 is related to an agreement to pay an additional cash amount based on the achievement of certain performance measures for up to five years after the acquisition date. The accrued contingent consideration was recorded as a liability at acquisition-date fair value using the income approach with assumed discount rates ranging from 4.5% to 5.3% over the applicable terms and an assumed payment probability of 100% over the applicable years. The range of the undiscounted amount the Company could pay under the contingent consideration agreement is between $0 and $4.1 million. In addition, during the year ended December 31, 2016, the Company paid $11.8 million for contingent consideration related to certain prior-period acquisitions, of which all but the accretion recorded during 2016 was accrued as of December 31, 2015.

In connection with certain prior-period acquisitions, the Company also made additional cash payments of $6.2 million, recorded an increase in deferred tax assets of $19.9 million, a decrease in current assets of $0.2 million, an increase of $2.5 million in deferred tax liabilities and a net decrease of $11.0 million in goodwill for measurement-period adjustments resulting from the finalization of certain income tax acquisition accounting. These adjustments did not have a material impact on the Company’s Consolidated Financial Statements in any period; therefore, the Company has not retrospectively adjusted such statements.

During 2015, the Company completed 12 acquisitions, composed of 10 physician group practices, a leading teleradiology physician services company and a complementary third-party receivables company for total consideration of $853.3 million, inclusive of cash acquired, of which $818.3 million was paid in cash, net of $23.0 million in cash acquired, $7.8 million was paid by issuing 114,306 shares of the Company’s common stock, $3.8 million was recorded as a contingent consideration liability, and $0.4 million was recorded within other current liabilities.

The results of operations of the acquisitions completed during the year ended December 31, 2016 and 2015 have been included in the Company’s Consolidated Financial Statements from the dates of acquisition. The following unaudited pro forma information combines the consolidated results of operations of the Company on a GAAP basis and the acquisitions completed during 2016 and 2015, including adjustments for pro forma amortization and interest expense, as if the transactions had occurred on January 1, 2015 and January 1, 2014, respectively (in thousands, except per share data):


	Years Ended December 31,
	2016		2015
Pro forma net revenue	$	3,336,120	$	3,276,266
Pro forma net income		329,720		348,788
Pro forma net income per common share (1):
Basic	$	3.57	$	3.75
Diluted	$	3.54	$	3.71
Weighted average common shares (1):
Basic		92,422		93,077
Diluted		93,109		93,960

(1)	The comparison of net income per common share is affected by the changes in the number of weighted average shares outstanding in each period.

The pro forma results do not necessarily represent results which would have occurred if the acquisitions had taken place at the beginning of the periods indicated, nor are they indicative of the results of future combined operations.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1497-128463

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-Section 50
-Paragraph 4
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
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Reference 15: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

7. Goodwill and Intangible Assets:

Goodwill was $3.8 billion and $3.4 billion at December 31, 2016 and 2015, respectively. The change in the carrying amount of goodwill of $479.0 million during the year ended December 31, 2016 is primarily related to the Company’s 2016 acquisitions. The Company expects that $179.8 million of the goodwill recorded during the year ended December 31, 2016 will be deductible for tax purposes. The change in the carrying amount of goodwill during the year ended December 31, 2015 of $590.0 million related to the 2015 acquisitions.

Intangible assets, net, consist of the following (in thousands):


	December 31, 2016
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Physician and hospital agreements	$	347,862	$	(168,488	)	$	179,374
Customer relationships		443,300		(27,368	)		415,932
Trade names		43,156		(1,604	)		41,552
Patented and other technology		37,503		(5,832	)		31,671

	$	871,821	$	(203,292	)	$	668,529


	December 31, 2015
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Physician and hospital agreements	$	265,465	$	(130,050	)	$	135,415
Customer relationships		248,880		(10,612	)		238,268
Trade names		28,620		(597	)		28,023
Patented and other technology		24,230		(1,717	)		22,513

	$	567,195	$	(142,976	)	$	424,219

During the year ended December 31, 2016, the Company recorded intangible assets related to acquisitions totaling $304.6 million, consisting of physician and hospital agreements of $82.4 million, customer relationships of $194.4 million, trade names of $14.5 million and patented and other technology of $13.3 million. The weighted-average amortization periods for these physician and hospital agreements, customer relationships, trade names and patented technology are approximately 10, 20, 20 and 10 years, respectively.

Amortization expense for intangible assets was $60.3 million, $42.0 million and $30.1 million for the years ended December 31, 2016, 2015 and 2014, respectively.

Amortization expense for existing intangible assets for the next five years is expected to be as follows (in thousands):


2017	$	65,560
2018		61,374
2019		57,060
2020		51,298
2021		44,896

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Accounts Payable and Accrued Expenses

12 Months Ended

Dec. 31, 2016

Payables and Accruals [Abstract]

Accounts Payable and Accrued Expenses

8. Accounts Payable and Accrued Expenses:

Accounts payable and accrued expenses consist of the following (in thousands):


	December 31,
	2016		2015
Accounts payable	$	28,474	$	21,969
Accrued salaries and bonuses		220,635		233,499
Accrued payroll taxes and benefits		67,830		58,979
Accrued professional liabilities		28,972		25,995
Accrued contingent consideration		6,566		13,565
Accrual for uncertain tax positions		—		7,000
Accrued interest		4,511		2,655
Other accrued expenses		50,950		32,145

	$	407,938	$	395,807

Accrued Professional Liabilities

12 Months Ended

Dec. 31, 2016

Health Care Organizations [Abstract]

Accrued Professional Liabilities

9. Accrued Professional Liabilities:

At December 31, 2016 and 2015, the Company’s total accrued professional liabilities of $202.1 million and $202.5 million, respectively, includes incurred but not reported loss reserves of $128.1 million and $135.1 million, respectively, and loss reserves for reported claims associated with self-insured retention amounts through the Company’s wholly owned captive insurance subsidiary of $74.0 million and $67.4 million, respectively.

The activity related to the Company’s total accrued professional liability for the years ended December 31, 2016, 2015 and 2014 is as follows (in thousands):


	Years Ended December 31,
	2016			2015			2014
Balance at beginning of year	$	202,527		$	168,369		$	158,691
Assumed liabilities through acquisition		—			35,968			—

Provision (adjustment) for losses related to:
Current year		38,129			39,204			39,386
Prior years		(25,428	)		(25,797	)		(16,125	)

Total provision for losses		12,701			13,407			23,261

Claim payments related to:
Current year		(766	)		(1,382	)		(293	)
Prior years		(12,410	)		(13,835	)		(13,290	)

Total payments		(13,176	)		(15,217	)		(13,583	)

Balance at end of year	$	202,052		$	202,527		$	168,369

The net decrease in the Company’s total accrued professional liability for the year ended December 31, 2016 is primarily related to overall favorable trends in the Company’s claims experience. The net increase in 2015 was primarily attributable to the assumption of a professional liability program in connection with an acquisition.

- Definition

The entire disclosure for the accrual for malpractice loss contingencies (general and professional liability) which may include the policy used for accruing the loss contingency, the nature and amount of any accrual, and any significant estimate used to determine the accrual.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 450
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6491354&loc=d3e6052-115624

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Topic 450
-SubTopic 20
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14453-108349

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 450
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6491354&loc=d3e6049-115624

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14472-108349

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14394-108349

+ Details

Line of Credit, Long-Term Debt and Capital Lease Obligations

12 Months Ended

Dec. 31, 2016

Debt Disclosure [Abstract]

Line of Credit, Long-Term Debt and Capital Lease Obligations

10. Line of Credit, Long-Term Debt and Capital Lease Obligations:

The Company’s credit agreement, as amended (the “Credit Agreement”) provides for a $1.7 billion unsecured revolving credit facility and a $200.0 million term loan and includes a $75.0 million sub-facility for swingline loans and a $37.5 million sub-facility for the issuance of letters of credit. The Company may increase the Credit Agreement to up to $2.2 billion on an unsecured basis, subject to the satisfaction of specified conditions. The Credit Agreement matures on October 29, 2019 and is guaranteed by substantially all of the Company’s subsidiaries and affiliated professional contractors. At the Company’s option, borrowings under the Credit Agreement (other than swingline loans) will bear interest at (i) the Alternate Base Rate (defined as the higher of (a) the prime rate, (b) the Federal Funds Rate plus 1/2 of 1.00% and (c) LIBOR for an interest period of one month plus 1.00%) plus an applicable margin rate ranging from 0.125% to 0.750% based on the Company’s consolidated leverage ratio or (ii) the LIBOR rate plus an applicable margin rate ranging from 1.125% to 1.750% based on the Company’s consolidated leverage ratio. Swingline loans will bear interest at the alternate base rate plus the applicable margin. The Credit Agreement also calls for other customary fees and charges, including an unused commitment fee ranging from 0.150% to 0.300% of the unused lending commitments, based on the Company’s consolidated leverage ratio.

The Credit Agreement contains customary covenants and restrictions, including covenants that require the Company to maintain a minimum interest coverage ratio, not to exceed a specified consolidated leverage ratio and to comply with laws. The Credit Agreement permits the Company to pay dividends and make certain other distributions, subject to limitations specified therein. Failure to comply with these covenants would constitute an event of default under the Credit Agreement, notwithstanding the ability of the Company to meet its debt service obligations. The Credit Agreement also includes various customary remedies for the lenders following an event of default, including the acceleration of repayment of outstanding amounts under the Credit Agreement. At December 31, 2016, the Company believes it was in compliance, in all material respects, with the financial covenants and other restrictions applicable under the Credit Agreement.

On December 8, 2015, the Company completed a private offering of $750.0 million aggregate principal amount of 2023 Senior Notes. The Company’s obligations under the 2023 Senior Notes are guaranteed on an unsecured senior basis by the same subsidiaries and affiliated professional contractors that guarantee the Credit Agreement. Interest on the 2023 Senior Notes accrues at the rate of 5.25% per annum and is payable semi-annually in arrears on June 1 and December 1.

At any time prior to December 1, 2018, the Company may redeem all or a portion of the 2023 Senior Notes at a redemption price equal to 100% of the principal amount of the notes being redeemed plus an applicable redemption premium and accrued and unpaid interest to the redemption date. In addition, at any time prior to December 1, 2018, the Company may redeem up to 35% of the aggregate principal amount of the 2023 Senior Notes at a redemption price of 105.250% of the principal amount thereof, plus accrued and unpaid interest, if any, to the redemption date, using proceeds from one or more equity offerings. On or after December 1, 2018, the Company may redeem all or a portion of the 2023 Senior Notes, at the redemption prices of 103.938% in 2018, 102.625% in 2019, 101.313% in 2020 and 100% in 2021 and thereafter, plus accrued and unpaid interest to the redemption date.

The indenture under which the 2023 Senior Notes are issued, among other things, limits our ability to (1) incur liens and (2) enter into sale and lease-back transactions, and also limits our ability to merge or dispose of all or substantially all of our assets, in all cases, subject to a number of customary exceptions. Although we are not required to make mandatory redemption or sinking fund payments with respect to the 2023 Senior Notes, upon the occurrence of a change in control of MEDNAX, we may be required to repurchase the 2023 Senior Notes at a purchase price equal to 101% of the aggregate principal amount of the 2023 Senior Notes repurchased plus accrued and unpaid interest.

The Company presents issuance costs related to long-term debt liabilities, other than revolving credit arrangements, as a direct deduction from the carrying value of that long-term debt.

The carrying value of the Company’s long-term debt was $1.7 billion and $1.3 billion at December 31, 2016 and 2015, respectively, and consisted of the following (in thousands):


	December 31, 2016
	Principal			Unamortized Debt Issuance Costs			Total
2023 Senior Notes	$	750,000		$	(11,109	)	$	738,891
Revolving line of credit		783,500			—			783,500
Term loan		180,000			(259	)		179,741

		1,713,500			(11,368	)		1,702,132
Less: Current portion		(20,000	)		—			(20,000	)

Long-term portion	$	1,693,500		$	(11,368	)	$	1,682,132


	December 31, 2015
	Principal			Unamortized Debt Issuance Costs			Total
2023 Senior Notes	$	750,000		$	(12,695	)	$	737,305
Revolving line of credit		343,500			—			343,500
Term loan		190,000			(401	)		189,599

		1,283,500			(13,096	)		1,270,404
Less: Current portion		(10,000	)		—			(10,000	)

Long-term portion	$	1,273,500		$	(13,096	)	$	1,260,404

The Company has outstanding letters of credit which reduced the amount available under the Credit Agreement by $0.4 million at December 31, 2016. At December 31, 2016, the Company had an available balance on its Credit Agreement of $916.1 million.

The carrying values of the Company’s variable rate revolving line of credit and term loan approximate fair value due to the short-term nature of the interest rates. The estimated fair value of the Company’s 2023 Notes was $773.4 million and $753.8 million, at December 31, 2016 and 2015, respectively, and was estimated using trading prices as of December 31, 2016 and December 31, 2015 as Level 2 inputs to estimate fair value.

Aggregate annual maturities of the Company’s term loan and 2023 Senior Notes as of December 31, 2016 are as follows (in thousands):


2017	$	20,000
2018		30,000
2019		130,000
2020		—
Thereafter		750,000

The Company’s capital lease obligations consist of the following (in thousands):


	December 31,
	2016			2015
Capital lease obligations	$	3,550		$	4,299
Less: Current portion		(2,054	)		(1,883	)

Long-term portion	$	1,496		$	2,416

The amounts due under the terms of the Company’s capital lease obligations at December 31, 2016 are as follows:


2017	$	2,054
2018		1,193
2019		156
2020		84
2021		63

Income Taxes

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Income Taxes

11. Income Taxes:

The components of the income tax provision are as follows (in thousands):


	December 31,
	2016		2015		2014
Federal:
Current	$	166,758	$	168,596	$	167,745
Deferred		15,596		12,866		2,262

		182,354		181,462		170,007

State:
Current		4,296		20,948		21,109
Deferred		2,553		1,628		297

		6,849		22,576		21,406

Total	$	189,203	$	204,038	$	191,413

The Company files its tax return on a consolidated basis with its subsidiaries. The remaining affiliated professional contractors file tax returns on an individual basis.

The effective tax rate was 36.80%, 37.76% and 37.63% for the years ended December 31, 2016, 2015 and 2014, respectively. During the three months ended September 30, 2016, the Company settled a certain tax matter with a taxing authority. In connection with this settlement, the Company’s effective income tax rate was favorably impacted by $10.6 million. After excluding this favorable impact, the effective tax rate for December 31, 2016 was 38.87%, as compared to 37.76% for 2015. The increase primarily relates to non-recurring discrete items that occurred in 2015 and an increase in the valuation allowance on deferred tax assets in 2016.

The differences between the effective rate and the United States federal income tax statutory rate are as follows:


	December 31,
	2016			2015			2014
Tax at statutory rate		35.00	%		35.00	%		35.00	%
State income tax, net of federal benefit		2.94			2.97			2.74
Non-deductible expenses		0.43			0.34			0.33
Change in accrual estimates relating to uncertain tax positions		(2.11	)		(0.43	)		(0.59	)
Change in valuation allowance		0.48			0.29			—
Other, net		0.06			(0.41	)		0.15

Income tax provision		36.80	%		37.76	%		37.63	%

All of the Company’s deferred tax assets and liabilities are classified as long-term. The significant components of deferred income tax assets and liabilities are as follows (in thousands):


	December 31,
	2016			2015
Allowance for uncollectible accounts	$	103,525		$	82,928
Reserves and accruals		62,212			66,655
Stock-based compensation		13,726			13,662
Net operating loss carryforward		49,156			51,505
Property and equipment		1,621			3,116
Other		1,610			2,723

Deferred tax assets before valuation allowance		231,850			220,589
Less: Valuation allowance		(4,014	)		(1,552	)

Deferred tax assets, net of valuation allowance		227,836			219,037

Gross deferred tax liabilities:
Amortization		(380,594	)		(311,303	)
Accrual to cash adjustment		(53,771	)		(55,046	)
Other		(1,023	)		(6,693	)

Total deferred tax liabilities		(435,388	)		(373,042	)

Net deferred tax liability	$	(207,552	)	$	(154,005	)

The income tax benefit related to the exercise of stock options, the vesting of restricted and deferred stock and the purchase of shares under the Company’s non-qualified employee stock purchase plan in excess of amounts recorded as equity compensation expense reduces taxes currently payable and is credited to additional paid-in capital. Such amounts totaled $4.2 million, $11.6 million and $17.5 million for the years ended December 31, 2016, 2015 and 2014, respectively.

The Company has net operating loss carryforwards for federal and state tax purposes totaling $130.0 million, $136.6 million, and $29.0 million at December 31, 2016, 2015 and 2014, respectively, expiring at various times in 2019 through 2036. The change in net operating loss carryforwards in 2015 as compared to 2014 was primarily due to timing differences related to the recognition of income for tax purposes associated with acquisitions.

As of December 31, 2016, 2015 and 2014, the Company’s liability for uncertain tax positions, excluding accrued interest and penalties, was $9.5 million, $18.4 million and $17.2 million, respectively. As of December 31, 2016, the Company had $9.5 million of uncertain tax positions that, if recognized, would favorably impact its effective tax rate.

The following table summarizes the activity related to the Company’s liability for uncertain tax positions for the years ended December 31, 2016, 2015 and 2014 (in thousands):


	Years Ended December 31,
	2016			2015			2014
Balance at beginning of year	$	18,447		$	17,165		$	14,902
Increases related to prior year tax positions		301			467			40
Decreases related to prior year tax positions		(3,927	)		(1,168	)		—
Increases related to current year tax positions		2,258			3,675			3,750
Settlements		(5,644	)		—			—
Decreases related to lapse of statutes of limitations		(1,966	)		(1,692	)		(1,527	)

Balance at end of year	$	9,469		$	18,447		$	17,165

During the year ended December 31, 2016, the Company decreased its liability for uncertain tax positions by a total of $9.0 million, primarily related to the settlement of a certain tax matter with a taxing authority and the expiration of statutes of limitation, partially offset by additional taxes on current year positions. During the year ended December 31, 2015, the Company increased its liability for uncertain tax positions by $1.2 million, primarily related to additional taxes on current year positions, partially offset by decreases due to the expiration of statutes of limitation and current year tax positions.

In addition, the Company anticipates that its liability for uncertain tax positions will be increased by $2.2 million for additional taxes and decreased by $2.1 million related to the expiration of certain statutes of limitation over the next 12 months.

The Company includes interest and penalties related to income tax liabilities in income tax expense. The Company recognized an income tax benefit of $7.9 million and income tax expense of $0.6 million and $0.3 million related to interest and penalties during the years ended December 31, 2016, 2015 and 2014, respectively. The 2016 benefit was primarily related to the settlement of the tax matter discussed above. At December 31, 2016 and 2015, the Company’s accrued liability for interest and penalties related to income tax liabilities totaled $1.4 million and $9.3 million, respectively.

The Company is currently subject to U.S. Federal and various state income tax examinations for the tax years 2012 through 2015.

Common and Common Equivalent Shares

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Common and Common Equivalent Shares

12. Common and Common Equivalent Shares:

The calculation of shares used in the basic and diluted net income per share calculation for the years ended December 31, 2016, 2015 and 2014 is as follows (in thousands):


	Years Ended December 31,
	2016		2015		2014
Weighted average number of common shares outstanding		92,422		93,077		98,588
Weighted average number of dilutive common share equivalents		687		883		1,299

Weighted average number of common and common equivalent shares outstanding		93,109		93,960		99,887

Antidilutive securities not included in the diluted net income per common share calculation		2		—		1

Stock Incentive Plans and Stock Purchase Plans

12 Months Ended

Dec. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Incentive Plans and Stock Purchase Plans

13. Stock Incentive Plans and Stock Purchase Plans:

The Company’s Amended and Restated 2008 Incentive Compensation Plan, as amended (the “Amended and Restated 2008 Incentive Plan”) provides for grants of stock options, stock appreciation rights, restricted stock, deferred stock, and other stock-related awards and performance awards that may be settled in cash, stock or other property.

Under the Amended and Restated 2008 Incentive Plan, options to purchase shares of common stock may be granted at a price not less than the fair market value of the shares on the date of grant. The options must be exercised within 10 years from the date of grant and generally become exercisable on a pro rata basis over a three-year period from the date of grant. The Company issues new shares of its common stock upon exercise of its stock options. Restricted stock awards generally vest over periods of three years upon the fulfillment of specified service-based conditions and in certain instances performance-based conditions. Deferred stock awards generally vest upon the satisfaction of specified performance-based conditions or service-based conditions. The Company recognizes compensation expense related to its restricted stock and deferred stock awards ratably over the corresponding vesting periods. At December 31, 2016, the Company had 4.5 million shares available for future grants and awards under its Amended and Restated 2008 Incentive Plan.

Under the Company’s 1996 Non-Qualified Employee Stock Purchase Plan, as amended (the “ESPP”), employees are permitted to purchase the Company’s common stock at 85% of market value on January 1st, April 1st, July 1st and October 1st of each year. Under the Company’s 2015 Non-Qualified Stock Purchase Plan (the “SPP”), certain eligible non-employee service providers are permitted to purchase the Company’s common stock at 90% of market value on January 1st, April 1st, July 1st and October 1st of each year upon the SPP’s effective date of January 1, 2016.

Each of the ESPP and the SPP provide for the issuance of an of aggregate 2.6 million shares of the Company’s common stock less the number of shares of common stock purchased under the other plan. The Company recognizes stock-based compensation expense for the discount received by participating employees and non-employee service providers. During the year ended December 31, 2016, 0.3 million shares were issued under the ESPP and SPP. At December 31, 2016, the Company had 2.3 million shares in aggregate reserved for issuance under the ESPP and SPP.

The Company recognized $34.0 million, $32.1 million and $31.7 million of stock-based compensation expense related to its stock incentive plans, the ESPP and the SPP during the years ended December 31, 2016, 2015 and 2014, respectively.

The activity related to the Company’s restricted stock awards and the corresponding weighted average grant-date fair values for the year ended December 31, 2016 are as follows:


	Number of Shares			Weighted Average Fair Value
Non-vested shares at January 1, 2016		1,013,791		$	61.50
Awarded		504,943		$	67.90
Forfeited		(52,957	)	$	66.18
Vested		(519,448	)	$	57.31

Non-vested shares at December 31, 2016		946,329		$	66.98

The aggregate fair value of the restricted and deferred stock that vested during the years ended December 31, 2016, 2015 and 2014 was $29.8 million, $31.6 million and $28.2 million, respectively.

The weighted average grant-date fair value of restricted and deferred stock awards that were granted during the years ended December 31, 2016, 2015 and 2014 was $67.90, $70.44 and $57.73, respectively.

At December 31, 2016, the total stock-based compensation cost related to non-vested restricted stock remaining to be recognized as compensation expense over a weighted-average period of 1.5 years was $28.5 million.

The Company did not grant any stock options during 2016 or 2015, and all stock-based compensation cost related to stock options has been recognized. The activity and certain other information related to the Company’s outstanding stock option awards for the year ended December 31, 2016 are as follows:


	Number of Stock Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Outstanding at January 1, 2016		585,387		$	27.96
Exercised		(175,101	)	$	27.08			$	6.8

Outstanding and exercisable at December 31, 2016		410,286		$	28.33		2.0	$	15.7

The aggregate intrinsic value of stock options exercised during the years ended December 31, 2016, 2015 and 2014 was $6.8 million, $11.3 million and $38.8 million, respectively.

The net excess tax benefit recognized in additional paid-in capital related primarily to stock options, restricted stock and deferred stock for the years ended December 31, 2016, 2015 and 2014 was $4.1 million, $11.6 million and $17.5 million, respectively. The cash proceeds received from the exercise of stock options for the years ended December 31, 2016, 2015 and 2014 were $4.7 million, $6.1 million and $30.1 million, respectively.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Common Stock Repurchase Programs	12 Months Ended
Common Stock Repurchase Programs	Dec. 31, 2016
Text Block [Abstract]
Common Stock Repurchase Programs	14. Common Stock Repurchase Programs: In July 2013, the Company’s Board of Directors authorized the repurchase of shares of the Company’s common stock up to an amount sufficient to offset the dilutive impact from the issuance of shares under the Company’s equity compensation programs. The share repurchase program allows the Company to make open market purchases from time-to-time based on general economic and market conditions and trading restrictions. The repurchase program also allows for the repurchase of shares of the Company’s common stock to offset the dilutive impact from the issuance of shares, if any, related to the Company’s acquisition program. During the year ended December 31, 2016, the Company repurchased 0.9 million shares of its common stock for $61.8 million, inclusive of 46,490 shares withheld to satisfy minimum stock withholding obligations of $3.2 million in connection with the vesting of restricted stock. In October 2014, the Company announced that its Board of Directors had authorized the repurchase of up to $600.0 million of shares of the Company’s common stock in addition to its existing share repurchase program. In December 2014, the Company entered into uncollared accelerated share repurchase (“ASR”) agreement with an investment bank. Under the ASR agreement, the Company agreed to purchase $200.0 million of its common stock in total. On December 17, 2014, the Company paid a total of $200.0 million to an investment bank, which in turn delivered to the Company 2.5 million shares of the Company’s common stock in total based on the market price of a share of Company common stock on December 12, 2014. The payment was recorded as a reduction to the respective components of shareholders’ equity. The final number of shares of common stock that the Company may receive, or may be required to remit, upon settlement under the ASR agreement was to be based upon the average daily volume weighted-average price of the Company’s common stock during the term of the ASR agreement, less a negotiated discount. The ASR agreement was funded by borrowings under the Company’s Credit Agreement discussed in Note 10. Final settlement of the ASR occurred in July 2015 with the delivery to the Company of 0.3 million additional shares of common stock. The final number of shares of common stock that the Company received was based upon the average daily volume weighted-average price of the Company’s common stock during the term of the ASR agreement, less a negotiated discount. In March 2015, the Company entered into a second uncollared ASR agreement with an investment bank. Under the ASR agreement, the Company agreed to purchase $200.0 million of its common stock in total. On March 16, 2015, the Company paid a total of $200.0 million to an investment bank, which in turn delivered to the Company 2.2 million shares of the Company’s common stock in total based on the market price of a share of Company common stock on March 12, 2015. The ASR agreement was funded by borrowings under the Company’s Credit Agreement, and the payment was recorded as a reduction to the respective components of shareholders’ equity. Final settlement of the ASR occurred in October 2015 with the delivery to the Company of 0.3 million additional shares of common stock. The final number of shares of common stock that the Company received was based upon the average daily volume weighted-average price of the Company’s common stock during the term of the ASR agreement, less a negotiated discount. During the year ended December 31, 2015, the Company repurchased 3.4 million shares of its common stock for $235.1 million, inclusive of shares delivered to the Company under the ASR agreements, and 18,282 shares withheld to satisfy minimum stock withholding obligations of $1.5 million in connection with the vesting of restricted stock units. The Company intends to utilize various methods to effect any future share repurchases, including, among others, open market purchases and accelerated share repurchase programs. The amount and timing of repurchases will depend upon several factors, including general economic and market conditions and trading restrictions.

Retirement Plans	12 Months Ended
Retirement Plans	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	15. Retirement Plans: The Company maintains six qualified contributory savings plans as allowed under Section 401(k) of the Internal Revenue Code and Section 1165(e) of the Puerto Rico Income Tax Act of 1954 (the “401(k) Plans”). The 401(k) Plans permit participant contributions and allow elective and, in certain situations, non-elective Company contributions based on each participant’s contribution or a specified percentage of eligible wages. Participants may defer a percentage of their annual compensation subject to the limits defined in the 401(k) Plans. The Company recorded expense of $45.2 million, $39.7 million and $34.3 million for the years ended December 31, 2016, 2015 and 2014, respectively, primarily related to the 401(k) Plans.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

16. Commitments and Contingencies:

The Company expects that audits, inquiries and investigations from government authorities and agencies will occur in the ordinary course of business. Such audits, inquiries and investigations and their ultimate resolutions, individually or in the aggregate, could have a material adverse effect on the Company’s business, financial condition, results of operations, cash flows and the trading price of its common stock. The Company has not included an accrual for these matters as of December 31, 2016 in its Consolidated Financial Statements, as the variables affecting any potential eventual liability depend on the currently unknown facts and circumstances that arise out of, and are specific to, any particular future audit, inquiry and investigation and cannot be reasonably estimated at this time.

In the ordinary course of business, the Company becomes involved in pending and threatened legal actions and proceedings, most of which involve claims of medical malpractice related to medical services provided by the Company’s affiliated physicians. The Company’s contracts with hospitals generally require the Company to indemnify them and their affiliates for losses resulting from the negligence of the Company’s affiliated physicians. The Company may also become subject to other lawsuits which could involve large claims and significant costs. The Company believes, based upon a review of pending actions and proceedings, that the outcome of such legal actions and proceedings will not have a material adverse effect on its business, financial condition, results of operations, cash flows and the trading price of its securities. The outcome of such actions and proceedings, however, cannot be predicted with certainty and an unfavorable resolution of one or more of them could have a material adverse effect on the Company’s business, financial condition, results of operations, cash flows and the trading price of its securities.

Although the Company currently maintains liability insurance coverage intended to cover professional liability and certain other claims, the Company cannot assure that its insurance coverage will be adequate to cover liabilities arising out of claims asserted against it in the future where the outcomes of such claims are unfavorable. With respect to professional liability risk, the Company generally self-insures a portion of this risk through its wholly owned captive insurance subsidiary. Liabilities in excess of the Company’s insurance coverage, including coverage for professional liability and certain other claims, could have a material adverse effect on the Company’s business, financial condition, results of operations, cash flows and the trading price of its securities.

The Company leases space for its regional, medical and business offices, storage space and temporary housing of medical staff. The Company also leases an aircraft. Rent expense for the years ended December 31, 2016, 2015 and 2014 was $38.0 million, $31.6 million and $27.8 million, respectively.

Future minimum lease payments under non-cancelable operating leases as of December 31, 2016 are as follows (in thousands):


2017	$	35,465
2018		27,421
2019		19,791
2020		13,132
2021		8,960
Thereafter		17,602

	$	122,371

Selected Quarterly Financial Information

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Information

17. Selected Quarterly Financial Information (Unaudited):

The following tables set forth a summary of the Company’s selected quarterly financial information for each of the four quarters ended December 31, 2016 and 2015 (in thousands, except for per share data):


	2016 Quarters
	First			Second			Third			Fourth
Net revenue	$	752,624		$	771,759		$	828,006		$	830,770

Operating expenses:
Practice salaries and benefits		491,811			484,625			521,832			532,952
Practice supplies and other operating expenses		27,046			26,992			31,641			32,737
General and administrative expenses		89,950			92,116			93,457			97,049
Depreciation and amortization		19,584			20,241			24,185			25,254

Total operating expenses		628,391			623,974			671,115			687,992

Income from operations		124,233			147,785			156,891			142,778
Investment and other income		618			410			221			770
Interest expense		(14,463	)		(15,058	)		(17,215	)		(16,356	)
Equity in earnings of unconsolidated affiliate		794			789			796			806

Total non-operating expenses		(13,051	)		(13,859	)		(16,198	)		(14,780	)
Income before income taxes		111,182			133,926			140,693			127,998
Income tax provision		43,411			51,601			44,272			49,919

Net income		67,771			82,325			96,421			78,079
Net loss attributable to noncontrolling interests		128			102			88			—

Net income attributable to MEDNAX, Inc.	$	67,899		$	82,427		$	96,509		$	78,079

Per common and common equivalent share data (1):
Net income attributable to MEDNAX, Inc.:
Basic	$	0.74		$	0.89		$	1.04		$	0.84

Diluted	$	0.73		$	0.89		$	1.04		$	0.84

Weighted average common shares:
Basic		92,269			92,182			92,604			92,728

Diluted		93,091			92,945			93,146			93,347

(1)	Basic and diluted per share amounts are computed for each of the periods presented. Accordingly, the sum of the quarterly per share amounts may not agree with the full year amount.


	2015 Quarters
	First			Second			Third			Fourth
Net revenue	$	639,395		$	676,588		$	722,273		$	741,740

Operating expenses:
Practice salaries and benefits		419,595			422,803			450,033			461,074
Practice supplies and other operating expenses		23,431			24,878			24,007			26,164
General and administrative expenses		67,936			72,401			80,185			85,393
Depreciation and amortization		13,612			15,549			16,918			18,149

Total operating expenses		524,574			535,631			571,143			590,780

Income from operations		114,821			140,957			151,130			150,960
Investment and other income		142			384			567			751
Interest expense		(3,267	)		(5,149	)		(6,201	)		(8,493	)
Equity in earnings of unconsolidated affiliate		821			745			784			777

Total non-operating expenses		(2,304	)		(4,020	)		(4,850	)		(6,965	)
Income before income taxes		112,517			136,937			146,280			143,995
Income tax provision		43,928			52,889			55,640			51,581

Net income		68,589			84,048			90,640			92,414
Net loss attributable to noncontrolling interests		118			82			141			288

Net income attributable to MEDNAX, Inc.	$	68,707		$	84,130		$	90,781		$	92,702

Per common and common equivalent share data (1):
Net income attributable to MEDNAX, Inc.:
Basic	$	0.73		$	0.91		$	0.98		$	1.00

Diluted	$	0.72		$	0.90		$	0.97		$	0.99

Weighted average common shares:
Basic		94,231			92,500			92,949			92,790

Diluted		95,325			93,495			93,646			93,536

(2)	Basic and diluted per share amounts are computed for each of the periods presented. Accordingly, the sum of the quarterly per share amounts may not agree with the full year amount.

Schedule II: Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2016

Valuation and Qualifying Accounts [Abstract]

Schedule II: Valuation and Qualifying Accounts

MEDNAX, INC.

Schedule II: Valuation and Qualifying Accounts


	Years Ended December 31,
	2016			2015			2014
Allowance for contractual adjustments and uncollectibles:
Balance at beginning of year	$	1,129,301		$	848,767		$	712,285
Amount charged against operating revenue		7,464,030			6,389,195			5,403,437
Accounts receivable contractual adjustments and write-offs (net of recoveries)		(7,368,965	)		(6,108,661	)		(5,266,955	)

Balance at end of year	$	1,224,366		$	1,129,301		$	848,767

All other schedules have been omitted because they are not applicable, not required or the information is included elsewhere herein.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Principles of Presentation

Principles of Presentation

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

New Accounting Pronouncements

Accounting Estimates and Assumptions

Accounting Estimates and Assumptions

Segment Reporting

Segment Reporting

The following table summarizes the Company’s net revenue by service line (in percentages):


	Years Ended December 31,
	2016			2015			2014
Neonatology and other pediatric subspecialties		39	%		44	%		50	%
Anesthesiology		39	%		37	%		36	%
Maternal-fetal medicine		8	%		9	%		9	%
Radiology		6	%		4	%		—
Management services		5	%		2	%		1	%
Pediatric cardiology		3	%		4	%		4	%

		100	%		100	%		100	%

Revenue Recognition

Revenue Recognition

Cash and Cash Equivalents

Cash and Cash Equivalents

Certain cash equivalents carried by the Company are subject to the fair value provisions of the accounting guidance for fair value measurements. See “Fair Value Measurements” below.

Investments

Investments

Property and Equipment

Property and Equipment

Business Acquisitions

Business Acquisitions

Goodwill and Other Intangible Assets

Goodwill and Other Intangible Assets

Long-Lived Assets

Long-Lived Assets

Common Stock Repurchases

Common Stock Repurchases

Professional Liability Coverage

Professional Liability Coverage

Income Taxes

Income Taxes

Stock Incentive Plans

Stock Incentive Plans

Net Income Per Common Share

Net Income Per Common Share

Fair Value Measurements

Fair Value Measurements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Schedule of Net Revenue by Service Line

The following table summarizes the Company’s net revenue by service line (in percentages):


	Years Ended December 31,
	2016			2015			2014
Neonatology and other pediatric subspecialties		39	%		44	%		50	%
Anesthesiology		39	%		37	%		36	%
Maternal-fetal medicine		8	%		9	%		9	%
Radiology		6	%		4	%		—
Management services		5	%		2	%		1	%
Pediatric cardiology		3	%		4	%		4	%

		100	%		100	%		100	%

Investments (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Schedule of Investments

Investments held are summarized as follows (in thousands):


	December 31, 2016				December 31, 2015
	Short-Term		Long-Term		Short-Term		Long-Term
Municipal debt securities	$	10,306	$	46,513	$	8,608	$	34,858
Federal home loan securities		—		28,747		—		26,715
Certificates of deposit		980		3,715		245		1,715

	$	11,286	$	78,975	$	8,853	$	63,288

Schedule of Contractual Maturities of Long-Term Investments

Contractual maturities of long-term investments are summarized as follows (in thousands):


	December 31,
	2016		2015
Due after one year through five years	$	70,005	$	60,383
Due after five years through seven years		8,970		2,905

	$	78,975	$	63,288

- Definition

Tabular disclosure of all investments in certain debt and equity securities for which the entity has the positive intent and ability to hold until maturity.

+ References + Details

Accounts Receivable and Net Revenue (Tables)

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Schedule of Accounts Receivable, Net

Accounts receivable, net consists of the following (in thousands):


	December 31,
	2016			2015
Gross accounts receivable	$	1,719,642		$	1,574,038
Allowance for contractual adjustments and uncollectibles		(1,224,366	)		(1,129,301	)

	$	495,276		$	444,737

Schedule of Net Revenue

Net revenue consists of the following (in thousands):


	Years Ended December 31,
	2016			2015			2014
Gross revenue	$	10,374,813		$	8,942,957		$	7,662,556
Contractual adjustments and uncollectibles		(7,464,030	)		(6,389,195	)		(5,403,437	)
Hospital contract administrative fees		272,376			226,234			179,794

	$	3,183,159		$	2,779,996		$	2,438,913

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consists of the following (in thousands):


	December 31,
	2016			2015
Building	$	26,572		$	26,382
Land		6,683			6,683
Equipment and other		213,521			169,903

		246,776			202,968
Accumulated depreciation		(143,708	)		(119,334	)

	$	103,068		$	83,634

Business Acquisitions (Tables)

12 Months Ended

Dec. 31, 2016

Business Combinations [Abstract]

Summary of Company's Preliminary Allocation of Purchase Price

The Company’s preliminary allocation of purchase price is as follows (in thousands):


	Third-Party Receivables Acquisition			Other Acquisitions			Total
Current assets	$	17,819		$	200		$	18,019
Property and equipment		5,807			866			6,673
Other noncurrent assets		115			689			804
Goodwill		190,977			299,005			489,982
Other intangible assets		221,870			82,756			304,626
Current liabilities		(5,863	)		(333	)		(6,196	)
Deferred income tax liabilities—long-term		(31,114	)		(22,388	)		(53,502	)
Other long-term liabilities		(829	)		—			(829	)

	$	398,782		$	360,795		$	759,577

Schedule of Pro Forma Information Combines Consolidated Results of Company and Business Acquisitions

The following unaudited pro forma information combines the consolidated results of operations of the Company on a GAAP basis and the acquisitions completed during 2016 and 2015, including adjustments for pro forma amortization and interest expense, as if the transactions had occurred on January 1, 2015 and January 1, 2014, respectively (in thousands, except per share data):


	Years Ended December 31,
	2016		2015
Pro forma net revenue	$	3,336,120	$	3,276,266
Pro forma net income		329,720		348,788
Pro forma net income per common share (1):
Basic	$	3.57	$	3.75
Diluted	$	3.54	$	3.71
Weighted average common shares (1):
Basic		92,422		93,077
Diluted		93,109		93,960

(1)	The comparison of net income per common share is affected by the changes in the number of weighted average shares outstanding in each period.

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Intangible Assets, Net

Intangible assets, net, consist of the following (in thousands):


	December 31, 2016
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Physician and hospital agreements	$	347,862	$	(168,488	)	$	179,374
Customer relationships		443,300		(27,368	)		415,932
Trade names		43,156		(1,604	)		41,552
Patented and other technology		37,503		(5,832	)		31,671

	$	871,821	$	(203,292	)	$	668,529


	December 31, 2015
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Physician and hospital agreements	$	265,465	$	(130,050	)	$	135,415
Customer relationships		248,880		(10,612	)		238,268
Trade names		28,620		(597	)		28,023
Patented and other technology		24,230		(1,717	)		22,513

	$	567,195	$	(142,976	)	$	424,219

Amortization Expenses for Existing Intangible Assets for the Next Five Years

Amortization expense for existing intangible assets for the next five years is expected to be as follows (in thousands):


2017	$	65,560
2018		61,374
2019		57,060
2020		51,298
2021		44,896

Accounts Payable and Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2016

Payables and Accruals [Abstract]

Schedule of Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses consist of the following (in thousands):


	December 31,
	2016		2015
Accounts payable	$	28,474	$	21,969
Accrued salaries and bonuses		220,635		233,499
Accrued payroll taxes and benefits		67,830		58,979
Accrued professional liabilities		28,972		25,995
Accrued contingent consideration		6,566		13,565
Accrual for uncertain tax positions		—		7,000
Accrued interest		4,511		2,655
Other accrued expenses		50,950		32,145

	$	407,938	$	395,807

Accrued Professional Liabilities (Tables)

12 Months Ended

Dec. 31, 2016

Health Care Organizations [Abstract]

Schedule of Accrued Professional Liability

The activity related to the Company’s total accrued professional liability for the years ended December 31, 2016, 2015 and 2014 is as follows (in thousands):


	Years Ended December 31,
	2016			2015			2014
Balance at beginning of year	$	202,527		$	168,369		$	158,691
Assumed liabilities through acquisition		—			35,968			—

Provision (adjustment) for losses related to:
Current year		38,129			39,204			39,386
Prior years		(25,428	)		(25,797	)		(16,125	)

Total provision for losses		12,701			13,407			23,261

Claim payments related to:
Current year		(766	)		(1,382	)		(293	)
Prior years		(12,410	)		(13,835	)		(13,290	)

Total payments		(13,176	)		(15,217	)		(13,583	)

Balance at end of year	$	202,052		$	202,527		$	168,369

Line of Credit, Long-Term Debt and Capital Lease Obligations (Tables)

12 Months Ended

Dec. 31, 2016

Debt Disclosure [Abstract]

Schedule of Long-Term Debt

The carrying value of the Company’s long-term debt was $1.7 billion and $1.3 billion at December 31, 2016 and 2015, respectively, and consisted of the following (in thousands):


	December 31, 2016
	Principal			Unamortized Debt Issuance Costs			Total
2023 Senior Notes	$	750,000		$	(11,109	)	$	738,891
Revolving line of credit		783,500			—			783,500
Term loan		180,000			(259	)		179,741

		1,713,500			(11,368	)		1,702,132
Less: Current portion		(20,000	)		—			(20,000	)

Long-term portion	$	1,693,500		$	(11,368	)	$	1,682,132


	December 31, 2015
	Principal			Unamortized Debt Issuance Costs			Total
2023 Senior Notes	$	750,000		$	(12,695	)	$	737,305
Revolving line of credit		343,500			—			343,500
Term loan		190,000			(401	)		189,599

		1,283,500			(13,096	)		1,270,404
Less: Current portion		(10,000	)		—			(10,000	)

Long-term portion	$	1,273,500		$	(13,096	)	$	1,260,404

Schedule of Aggregate Annual Maturities of Term Loan and 2023 Senior Notes

Aggregate annual maturities of the Company’s term loan and 2023 Senior Notes as of December 31, 2016 are as follows (in thousands):


2017	$	20,000
2018		30,000
2019		130,000
2020		—
Thereafter		750,000

Schedule of Capital Lease Obligations

The Company’s capital lease obligations consist of the following (in thousands):


	December 31,
	2016			2015
Capital lease obligations	$	3,550		$	4,299
Less: Current portion		(2,054	)		(1,883	)

Long-term portion	$	1,496		$	2,416

Schedule of Amounts Due Under Terms of Capital Lease Obligations

The amounts due under the terms of the Company’s capital lease obligations at December 31, 2016 are as follows:


2017	$	2,054
2018		1,193
2019		156
2020		84
2021		63

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Summary of Components of Income Tax Provision

The components of the income tax provision are as follows (in thousands):


	December 31,
	2016		2015		2014
Federal:
Current	$	166,758	$	168,596	$	167,745
Deferred		15,596		12,866		2,262

		182,354		181,462		170,007

State:
Current		4,296		20,948		21,109
Deferred		2,553		1,628		297

		6,849		22,576		21,406

Total	$	189,203	$	204,038	$	191,413

Schedule of Differences Between Effective Rate and United States Federal Income Tax Statutory Rate

The differences between the effective rate and the United States federal income tax statutory rate are as follows:


	December 31,
	2016			2015			2014
Tax at statutory rate		35.00	%		35.00	%		35.00	%
State income tax, net of federal benefit		2.94			2.97			2.74
Non-deductible expenses		0.43			0.34			0.33
Change in accrual estimates relating to uncertain tax positions		(2.11	)		(0.43	)		(0.59	)
Change in valuation allowance		0.48			0.29			—
Other, net		0.06			(0.41	)		0.15

Income tax provision		36.80	%		37.76	%		37.63	%

Significant Components of Deferred Income Tax Assets And Liabilities

The significant components of deferred income tax assets and liabilities are as follows (in thousands):


	December 31,
	2016			2015
Allowance for uncollectible accounts	$	103,525		$	82,928
Reserves and accruals		62,212			66,655
Stock-based compensation		13,726			13,662
Net operating loss carryforward		49,156			51,505
Property and equipment		1,621			3,116
Other		1,610			2,723

Deferred tax assets before valuation allowance		231,850			220,589
Less: Valuation allowance		(4,014	)		(1,552	)

Deferred tax assets, net of valuation allowance		227,836			219,037

Gross deferred tax liabilities:
Amortization		(380,594	)		(311,303	)
Accrual to cash adjustment		(53,771	)		(55,046	)
Other		(1,023	)		(6,693	)

Total deferred tax liabilities		(435,388	)		(373,042	)

Net deferred tax liability	$	(207,552	)	$	(154,005	)

Schedule of Activity Related to Gross Unrecognized Tax Benefits

The following table summarizes the activity related to the Company’s liability for uncertain tax positions for the years ended December 31, 2016, 2015 and 2014 (in thousands):


	Years Ended December 31,
	2016			2015			2014
Balance at beginning of year	$	18,447		$	17,165		$	14,902
Increases related to prior year tax positions		301			467			40
Decreases related to prior year tax positions		(3,927	)		(1,168	)		—
Increases related to current year tax positions		2,258			3,675			3,750
Settlements		(5,644	)		—			—
Decreases related to lapse of statutes of limitations		(1,966	)		(1,692	)		(1,527	)

Balance at end of year	$	9,469		$	18,447		$	17,165

Common and Common Equivalent Shares (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Schedule of Calculation of Shares Used in Basic and Diluted Net Income Per Share

The calculation of shares used in the basic and diluted net income per share calculation for the years ended December 31, 2016, 2015 and 2014 is as follows (in thousands):


	Years Ended December 31,
	2016		2015		2014
Weighted average number of common shares outstanding		92,422		93,077		98,588
Weighted average number of dilutive common share equivalents		687		883		1,299

Weighted average number of common and common equivalent shares outstanding		93,109		93,960		99,887

Antidilutive securities not included in the diluted net income per common share calculation		2		—		1

Stock Incentive Plans and Stock Purchase Plans (Tables)

12 Months Ended

Dec. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Restricted Stock Awards

The activity related to the Company’s restricted stock awards and the corresponding weighted average grant-date fair values for the year ended December 31, 2016 are as follows:


	Number of Shares			Weighted Average Fair Value
Non-vested shares at January 1, 2016		1,013,791		$	61.50
Awarded		504,943		$	67.90
Forfeited		(52,957	)	$	66.18
Vested		(519,448	)	$	57.31

Non-vested shares at December 31, 2016		946,329		$	66.98

Schedule of Activity and Certain Other Information Related to Stock Option Awards

The activity and certain other information related to the Company’s outstanding stock option awards for the year ended December 31, 2016 are as follows:


	Number of Stock Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Outstanding at January 1, 2016		585,387		$	27.96
Exercised		(175,101	)	$	27.08			$	6.8

Outstanding and exercisable at December 31, 2016		410,286		$	28.33		2.0	$	15.7

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases

Future minimum lease payments under non-cancelable operating leases as of December 31, 2016 are as follows (in thousands):


2017	$	35,465
2018		27,421
2019		19,791
2020		13,132
2021		8,960
Thereafter		17,602

	$	122,371

Selected Quarterly Financial Information (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Summary of Company's Selected Quarterly Financial Information


	2016 Quarters
	First			Second			Third			Fourth
Net revenue	$	752,624		$	771,759		$	828,006		$	830,770

Operating expenses:
Practice salaries and benefits		491,811			484,625			521,832			532,952
Practice supplies and other operating expenses		27,046			26,992			31,641			32,737
General and administrative expenses		89,950			92,116			93,457			97,049
Depreciation and amortization		19,584			20,241			24,185			25,254

Total operating expenses		628,391			623,974			671,115			687,992

Income from operations		124,233			147,785			156,891			142,778
Investment and other income		618			410			221			770
Interest expense		(14,463	)		(15,058	)		(17,215	)		(16,356	)
Equity in earnings of unconsolidated affiliate		794			789			796			806

Total non-operating expenses		(13,051	)		(13,859	)		(16,198	)		(14,780	)
Income before income taxes		111,182			133,926			140,693			127,998
Income tax provision		43,411			51,601			44,272			49,919

Net income		67,771			82,325			96,421			78,079
Net loss attributable to noncontrolling interests		128			102			88			—

Net income attributable to MEDNAX, Inc.	$	67,899		$	82,427		$	96,509		$	78,079

Per common and common equivalent share data (1):
Net income attributable to MEDNAX, Inc.:
Basic	$	0.74		$	0.89		$	1.04		$	0.84

Diluted	$	0.73		$	0.89		$	1.04		$	0.84

Weighted average common shares:
Basic		92,269			92,182			92,604			92,728

Diluted		93,091			92,945			93,146			93,347

(1)	Basic and diluted per share amounts are computed for each of the periods presented. Accordingly, the sum of the quarterly per share amounts may not agree with the full year amount.


	2015 Quarters
	First			Second			Third			Fourth
Net revenue	$	639,395		$	676,588		$	722,273		$	741,740

Operating expenses:
Practice salaries and benefits		419,595			422,803			450,033			461,074
Practice supplies and other operating expenses		23,431			24,878			24,007			26,164
General and administrative expenses		67,936			72,401			80,185			85,393
Depreciation and amortization		13,612			15,549			16,918			18,149

Total operating expenses		524,574			535,631			571,143			590,780

Income from operations		114,821			140,957			151,130			150,960
Investment and other income		142			384			567			751
Interest expense		(3,267	)		(5,149	)		(6,201	)		(8,493	)
Equity in earnings of unconsolidated affiliate		821			745			784			777

Total non-operating expenses		(2,304	)		(4,020	)		(4,850	)		(6,965	)
Income before income taxes		112,517			136,937			146,280			143,995
Income tax provision		43,928			52,889			55,640			51,581

Net income		68,589			84,048			90,640			92,414
Net loss attributable to noncontrolling interests		118			82			141			288

Net income attributable to MEDNAX, Inc.	$	68,707		$	84,130		$	90,781		$	92,702

Per common and common equivalent share data (1):
Net income attributable to MEDNAX, Inc.:
Basic	$	0.73		$	0.91		$	0.98		$	1.00

Diluted	$	0.72		$	0.90		$	0.97		$	0.99

Weighted average common shares:
Basic		94,231			92,500			92,949			92,790

Diluted		95,325			93,495			93,646			93,536

(2)	Basic and diluted per share amounts are computed for each of the periods presented. Accordingly, the sum of the quarterly per share amounts may not agree with the full year amount.

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 08, 2015
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents maturity description	90 days or less
Additional amounts to be paid in cash or common stock based on achievement of performance measures within period, maximum years	5 years
Money market funds fair value	$ 12.4	$ 13.9
Cash surrender fair value of life insurance	15.8	14.5
Contingent consideration liabilities related to acquisitions, fair value	$ 17.3	$ 24.9
5.25% Senior Unsecured Notes Due 2023 [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt instrument interest rate			5.25%
Variable Interest Entity, Primary Beneficiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Consolidation method ownership percentage in joint venture	75.00%
Unnamed Corporate Joint Venture [Member]
Summary Of Significant Accounting Policies [Line Items]
Equity method ownership percentage in joint venture	37.50%
Government Contracts Concentration Risk [Member] \| Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of net accounts receivable	17.00%	19.00%
Buildings [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	20 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Long-term investments maturity period, in years	7 years
Short-Term investments maturity period, in years	1 year
Intangible assets finite lives	20 years
Maximum [Member] \| Medical Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	7 years
Maximum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	7 years
Maximum [Member] \| Software and Software Development Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	7 years
Maximum [Member] \| Furniture [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	7 years
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Long-term investments maturity period, in years	1 year
Intangible assets finite lives	1 year
Minimum [Member] \| Medical Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	3 years
Minimum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	3 years
Minimum [Member] \| Software and Software Development Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	3 years
Minimum [Member] \| Furniture [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives, years	3 years

Summary of Significant Accounting Policies - Schedule of Net Revenue by Service Line (Detail) - Product Concentration Risk [Member] - Sales Revenue, Services, Net [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net revenue in percentage	100.00%	100.00%	100.00%
Neonatology and Other Pediatric Subspecialties [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	39.00%	44.00%	50.00%
Anesthesiology [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	39.00%	37.00%	36.00%
Maternal-Fetal Medicine [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	8.00%	9.00%	9.00%
Radiology [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	6.00%	4.00%
Management Services [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	5.00%	2.00%	1.00%
Pediatric Cardiology [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	3.00%	4.00%	4.00%

Investments - Schedule of Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Short-Term	$ 11,286	$ 8,853
Long-Term	78,975	63,288
Municipal Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Short-Term	10,306	8,608
Long-Term	46,513	34,858
Federal Home Loan Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Long-Term	28,747	26,715
Certificates of Deposit [Member]
Schedule of Held-to-maturity Securities [Line Items]
Short-Term	980	245
Long-Term	$ 3,715	$ 1,715

Investments - Schedule of Contractual Maturities of Long-Term Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Due after one year through five years	$ 70,005	$ 60,383
Due after five years through seven years	8,970	2,905
Total	$ 78,975	$ 63,288

Accounts Receivable - Schedule of Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Gross accounts receivable	$ 1,719,642	$ 1,574,038
Allowance for contractual adjustments and uncollectibles	(1,224,366)	(1,129,301)
Accounts receivable, net	$ 495,276	$ 444,737

Accounts Receivable and Net Revenue - Schedule of Net Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Gross revenue									$ 10,374,813	$ 8,942,957	$ 7,662,556
Contractual adjustments and uncollectibles									(7,464,030)	(6,389,195)	(5,403,437)
Hospital contract administrative fees									272,376	226,234	179,794
Net revenue	$ 830,770	$ 828,006	$ 771,759	$ 752,624	$ 741,740	$ 722,273	$ 676,588	$ 639,395	$ 3,183,159	$ 2,779,996	$ 2,438,913

Accounts Receivable and Net Revenue - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Accounts receivable, net	$ 495,276				$ 444,737				$ 495,276	$ 444,737
Net patient service revenue	$ 830,770	$ 828,006	$ 771,759	$ 752,624	$ 741,740	$ 722,273	$ 676,588	$ 639,395	$ 3,183,159	$ 2,779,996	$ 2,438,913

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Building	$ 26,572	$ 26,382
Land	6,683	6,683
Equipment and other	213,521	169,903
Property and equipment, gross	246,776	202,968
Accumulated depreciation	(143,708)	(119,334)
Property and equipment, net	$ 103,068	$ 83,634

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Medical and other equipment held under capital leases	$ 246,776	$ 202,968
Accumulated depreciation of property and equipment held under capital leases	143,708	119,334
Recorded depreciation expense	29,000	22,200	$ 15,900
Medical and Other Equipment Held under Capital Lease [Member]
Property, Plant and Equipment [Line Items]
Medical and other equipment held under capital leases	6,200	5,400
Accumulated depreciation of property and equipment held under capital leases	$ 4,000	$ 2,300

Business Acquisitions - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) Acquisition Company	Dec. 31, 2015 USD ($) Acquisition Company shares
Business Acquisition [Line Items]
Number of physician group practices acquired \| Company	13	10
Number of anesthesiology practices acquired \| Company	8
Number of other pediatric subspecialty practices acquired \| Company	2
Number of neonatology practices acquired \| Company	1
Total business acquisition consideration, net of cash acquired	$ 759.6	$ 853.3
Cash payments to acquire businesses	756.1	818.3
Contingent consideration liability	$ 3.5	$ 3.8
Number of maternal-fetal medicine practices acquired \| Company	1
Number of pediatric cardiology practices acquired \| Company	1
Number of third-party receivables companies acquired \| Company	1	1
Number of patient engagement software company acquired \| Company	1
Number of business acquired \| Acquisition	15	12
Cash acquired from acquisition	$ 15.0	$ 23.0
Additional amounts to be paid in cash or common stock based on achievement of performance measures within period, maximum years	5 years
Additional cash payment for prior-period acquisitions	$ 11.8
Business acquisition, other current liabilities		0.4
Payments to acquire business by issue of common stock		$ 7.8
Number of shares of common stock issued \| shares		114,306
Number of teleradiology physician services acquired \| Company		1
Prior-Period Acquisitions [Member]
Business Acquisition [Line Items]
Additional cash payment for prior-period acquisitions	6.2
Increase in deferred tax assets	19.9
Decrease to goodwill resulting from finalization of tax acquisition accounting	(11.0)
Decrease in current assets	0.2
Increase in deferred tax liabilities	$ 2.5
Contingent Consideration [Member]
Business Acquisition [Line Items]
Additional amounts to be paid in cash or common stock based on achievement of performance measures within period, maximum years	5 years
Assumed payment probability of contingent consideration payment	100.00%
Range of the undiscounted amount under contingent consideration agreement, low	$ 0.0
Range of the undiscounted amount under contingent consideration agreement, high	$ 4.1
Minimum [Member] \| Contingent Consideration [Member]
Business Acquisition [Line Items]
Assumed discount rates for acquisition-date fair value	4.50%
Maximum [Member] \| Contingent Consideration [Member]
Business Acquisition [Line Items]
Assumed discount rates for acquisition-date fair value	5.30%

Business Acquisitions - Summary of Company's Preliminary Allocation of Purchase Price (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 3,845,157	$ 3,366,150
Third-Party Receivables Acquisition [Member]
Business Acquisition [Line Items]
Current assets	17,819
Property and equipment	5,807
Other noncurrent assets	115
Goodwill	190,977
Other intangible assets	221,870
Current liabilities	(5,863)
Deferred income tax liabilities - long-term	(31,114)
Other long-term liabilities	(829)
Total assets and liabilities	398,782
Other Acquisition [Member]
Business Acquisition [Line Items]
Current assets	200
Property and equipment	866
Other noncurrent assets	689
Goodwill	299,005
Other intangible assets	82,756
Current liabilities	(333)
Deferred income tax liabilities - long-term	(22,388)
Total assets and liabilities	360,795
Third-Party Receivable And Other Acquisition [Member]
Business Acquisition [Line Items]
Current assets	18,019
Property and equipment	6,673
Other noncurrent assets	804
Goodwill	489,982
Other intangible assets	304,626
Current liabilities	(6,196)
Deferred income tax liabilities - long-term	(53,502)
Other long-term liabilities	(829)
Total assets and liabilities	$ 759,577

Business Acquisitions - Schedule of Pro Forma Information Combines Consolidated Results of Company and Business Acquisitions (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Pro forma net revenue	$ 3,336,120	$ 3,276,266
Pro forma net income	$ 329,720	$ 348,788
Pro forma net income per common share, Basic	$ 3.57	$ 3.75
Pro forma net income per common share, Diluted	$ 3.54	$ 3.71
Weighted average common shares, Basic	92,422	93,077
Weighted average common shares, Diluted	93,109	93,960

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Other Intangible Asset [Line Items]
Goodwill	$ 3,845,157	$ 3,366,150
Change in goodwill carrying amount	479,000	590,000
Goodwill deductible for tax purpose	179,800
Intangible assets related to acquisitions	304,600
Amortization expense for intangible assets	60,300	$ 42,000	$ 30,100
Physician And Hospital Agreements [Member]
Goodwill And Other Intangible Asset [Line Items]
Intangible assets related to acquisitions	$ 82,400
Weighted average amortization period	10 years
Customer Relationships [Member]
Goodwill And Other Intangible Asset [Line Items]
Intangible assets related to acquisitions	$ 194,400
Weighted average amortization period	20 years
Trade Names [Member]
Goodwill And Other Intangible Asset [Line Items]
Intangible assets related to acquisitions	$ 14,500
Weighted average amortization period	20 years
Patented and Other Technology [Member]
Goodwill And Other Intangible Asset [Line Items]
Intangible assets related to acquisitions	$ 13,300
Weighted average amortization period	10 years

Goodwill and Intangible Assets - Summary of Intangible Assets, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 871,821	$ 567,195
Accumulated Amortization	(203,292)	(142,976)
Net Carrying Value	668,529	424,219
Physician And Hospital Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	347,862	265,465
Accumulated Amortization	(168,488)	(130,050)
Net Carrying Value	179,374	135,415
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	443,300	248,880
Accumulated Amortization	(27,368)	(10,612)
Net Carrying Value	415,932	238,268
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	43,156	28,620
Accumulated Amortization	(1,604)	(597)
Net Carrying Value	41,552	28,023
Patented and Other Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	37,503	24,230
Accumulated Amortization	(5,832)	(1,717)
Net Carrying Value	$ 31,671	$ 22,513

Goodwill and Intangible Assets - Amortization Expenses for Existing Intangible Assets for the Next Five Years (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for existing other intangible assets, 2017	$ 65,560
Amortization expense for existing other intangible assets, 2018	61,374
Amortization expense for existing other intangible assets, 2019	57,060
Amortization expense for existing other intangible assets, 2020	51,298
Amortization expense for existing other intangible assets, 2021	$ 44,896

Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accounts payable	$ 28,474	$ 21,969
Accrued salaries and bonuses	220,635	233,499
Accrued payroll taxes and benefits	67,830	58,979
Accrued professional liabilities	28,972	25,995
Accrued contingent consideration	6,566	13,565
Accrual for uncertain tax positions		7,000
Accrued interest	4,511	2,655
Other accrued expenses	50,950	32,145
Accounts payable and accrued expenses, total	$ 407,938	$ 395,807

Accrued Professional Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Total accrued professional liability	$ 202,052	$ 202,527	$ 168,369	$ 158,691
Accrued professional liability incurred but loss reserves not reported for claims	128,100	135,100
Accrued professional liability incurred and loss reserves reported for claims	$ 74,000	$ 67,400

Accrued Professional Liabilities - Schedule of Accrued Professional Liability (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Balance at beginning of year	$ 202,527	$ 168,369	$ 158,691
Assumed liabilities through acquisition		35,968
Provision (adjustment) for losses related to Current year	38,129	39,204	39,386
Provision (adjustment) for losses related to Prior years	(25,428)	(25,797)	(16,125)
Total provision for losses	12,701	13,407	23,261
Claim payments related to Current year	(766)	(1,382)	(293)
Claim payments related to Prior years	(12,410)	(13,835)	(13,290)
Total payments	(13,176)	(15,217)	(13,583)
Balance at end of year	$ 202,052	$ 202,527	$ 168,369

Line of Credit, Long-Term Debt and Capital Lease Obligations - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 08, 2015
Debt Instrument [Line Items]
Line of Credit facility, maturity date	Oct. 29, 2019
Line of Credit facility, estimated increase in borrowings	$ 2,200,000,000
Long term debt	$ 1,702,132,000	$ 1,270,404,000
Letters of credit outstanding amount		400,000
Line of Credit facility, available balance		916,100,000
Minimum [Member]
Debt Instrument [Line Items]
Commitment fee percentage	0.15%
Maximum [Member]
Debt Instrument [Line Items]
Commitment fee percentage	0.30%
Alternate Base Rate [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	Federal Funds Rate plus 1/2 of 1.00%
Alternate Base Rate [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	LIBOR for an interest period of one month plus 1.00%
Debt instrument, variable interest rate	1.00%
Applicable Margin Rate [Member] \| LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, variable interest rate	0.125%
Applicable Margin Rate [Member] \| LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, variable interest rate	0.75%
Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit facility, borrowing capacity	$ 1,700,000,000
Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit facility, borrowing capacity	200,000,000
Long term debt	179,741,000	189,599,000
Swingline Loans [Member]
Debt Instrument [Line Items]
Line of Credit facility, borrowing capacity	75,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Line of Credit facility, borrowing capacity	$ 37,500,000
5.25% Senior Unsecured Notes Due 2023 [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt			$ 750,000,000
Debt instrument interest rate			5.25%
Debt instrument maturity date description	Payable semi-annually in arrears on June 1 and December 1
Debt instrument, maturity year	2023
Long term debt	$ 738,891,000	737,305,000
Estimated fair value of notes	$ 773,400,000	$ 753,800,000
5.25% Senior Unsecured Notes Due 2023 [Member] \| Change In Control [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	101.00%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption Before 2018 [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	100.00%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption Before 2018 [Member] \| Redeem up to 35% of Aggregate Principal Amount [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	35.00%
Redemption price percentage of aggregate principal amount redeemed	105.25%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption in 2018 [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	103.938%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption in 2019[Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	102.625%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption in 2020 [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	101.313%
5.25% Senior Unsecured Notes Due 2023 [Member] \| Redemption in 2021 and Thereafter [Member]
Debt Instrument [Line Items]
Redemption percentage of principal amount	100.00%

Line of Credit, Long-Term Debt and Capital Lease Obligations - Schedule of Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt instrument principal amount	$ 1,713,500	$ 1,283,500
Less: Current portion, principal	(20,000)	(10,000)
Debt instrument principal long-term portion	1,693,500	1,273,500
Unamortized debt issuance cost	(11,368)	(13,096)
Less: Current portion, unamortized debt issuance costs	0	0
Long-term portion, principal, unamortized debt issuance costs	(11,368)	(13,096)
Long term debt	1,702,132	1,270,404
Less: Current portion	(20,000)	(10,000)
Long-term portion	1,682,132	1,260,404
5.25% Senior Unsecured Notes Due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	750,000	750,000
Unamortized debt issuance cost	(11,109)	(12,695)
Long term debt	738,891	737,305
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	783,500	343,500
Long term debt	783,500	343,500
Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	180,000	190,000
Unamortized debt issuance cost	(259)	(401)
Long term debt	$ 179,741	$ 189,599

Line of Credit, Long-Term Debt and Capital Lease Obligations - Schedule of Aggregate Annual Maturities of Term Loan and 2023 Senior Notes (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	$ 20,000
2018	30,000
2019	130,000
2020	0
Thereafter	$ 750,000

Line of Credit, Long-Term Debt and Capital Lease Obligations - Schedule of Capital Lease Obligations (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Capital lease obligations	$ 3,550	$ 4,299
Less: Current portion	(2,054)	(1,883)
Long-term portion	$ 1,496	$ 2,416

Line of Credit, Long-Term Debt and Capital Lease Obligations - Schedule of Amounts Due Under Terms of Capital Lease Obligations (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Debt Disclosure [Abstract]
2017	$ 2,054
2018	1,193
2019	156
2020	84
2021	$ 63

Income Taxes - Summary of Components of Income Tax Provision (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal, Current									$ 166,758	$ 168,596	$ 167,745
Federal, Deferred									15,596	12,866	2,262
Federal income tax provision, Total									182,354	181,462	170,007
State, Current									4,296	20,948	21,109
State, Deferred									2,553	1,628	297
State income tax provision, Total									6,849	22,576	21,406
Income tax provision, Total	$ 49,919	$ 44,272	$ 51,601	$ 43,411	$ 51,581	$ 55,640	$ 52,889	$ 43,928	$ 189,203	$ 204,038	$ 191,413

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Effective tax rate									36.80%	37.76%	37.63%
Effective income tax rate favorable impact of change in uncertain tax positions		$ 10,600
Effective tax rate excluding impact of tax settlement									38.87%	37.76%
Adjustment to additional paid-in capital for excess tax benefits related to stock-based awards									$ 4,200	$ 11,600	$ 17,500
Net operating loss carryforwards for federal and state tax	$ 130,000				$ 136,600				130,000	136,600	29,000
Uncertain tax position liability	9,469				18,447				9,469	18,447	17,165	$ 14,902
Unrecognized tax benefits that would impact effective tax rate	9,500								9,500
Increase (decrease) in uncertain tax position									(9,000)	1,200
Expected increase in uncertain tax position in the next twelve months	2,200								2,200
Expected decrease in uncertain tax position in the next twelve months	2,100								2,100
Income tax expense (benefit)	49,919	$ 44,272	$ 51,601	$ 43,411	51,581	$ 55,640	$ 52,889	$ 43,928	189,203	204,038	191,413
Company's accrued liability for interest and penalties related to income tax liabilities	$ 1,400				$ 9,300				1,400	9,300
Interest and Penalties [Member]
Income Tax [Line Items]
Income tax expense (benefit)									$ (7,900)	$ 600	$ 300
Earliest Tax Year [Member]
Income Tax [Line Items]
Federal and state income tax examinations									2012
Latest Tax Year [Member]
Income Tax [Line Items]
Federal and state income tax examinations									2015
Minimum [Member]
Income Tax [Line Items]
Expiration period of operating loss carryforwards									2019
Maximum [Member]
Income Tax [Line Items]
Expiration period of operating loss carryforwards									2036

Income Taxes - Schedule of Differences Between Effective Rate and United States Federal Income Tax Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax at statutory rate	35.00%	35.00%	35.00%
State income tax, net of federal benefit	2.94%	2.97%	2.74%
Non-deductible expenses	0.43%	0.34%	0.33%
Change in accrual estimates relating to uncertain tax positions	(2.11%)	(0.43%)	(0.59%)
Change in valuation allowance	0.48%	0.29%
Other, net	0.06%	(0.41%)	0.15%
Income tax provision	36.80%	37.76%	37.63%

Income Taxes - Significant Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Allowance for uncollectible accounts	$ 103,525	$ 82,928
Reserves and accruals	62,212	66,655
Stock-based compensation	13,726	13,662
Net operating loss carryforward	49,156	51,505
Property and equipment	1,621	3,116
Other	1,610	2,723
Deferred tax assets before valuation allowance	231,850	220,589
Less: Valuation allowance	(4,014)	(1,552)
Total deferred tax assets	227,836	219,037
Gross deferred tax liabilities:
Amortization	(380,594)	(311,303)
Accrual to cash adjustment	(53,771)	(55,046)
Other	(1,023)	(6,693)
Total deferred tax liabilities	(435,388)	(373,042)
Net deferred tax liability	$ (207,552)	$ (154,005)

Income Taxes - Schedule of Activity Related to Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 18,447	$ 17,165	$ 14,902
Increases related to prior year tax positions	301	467	40
Decreases related to prior year tax positions	(3,927)	(1,168)
Increases related to current year tax positions	2,258	3,675	3,750
Settlements	(5,644)
Decreases related to lapse of statutes of limitations	(1,966)	(1,692)	(1,527)
Balance at end of year	$ 9,469	$ 18,447	$ 17,165

Common and Common Equivalent Shares - Schedule of Calculation of Shares Used in Basic and Diluted Net Income Per Share (Detail) - shares shares in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Weighted average number of common shares outstanding	92,728	92,604	92,182	92,269	92,790	92,949	92,500	94,231	92,422	93,077	98,588
Weighted average number of dilutive common share equivalents									687	883	1,299
Weighted average number of common and common equivalent shares outstanding	93,347	93,146	92,945	93,091	93,536	93,646	93,495	95,325	93,109	93,960	99,887
Antidilutive securities not included in the diluted net income per common share calculation									2		1

Stock Incentive Plans and Stock Purchase Plans - Additional Information (Detail) - USD ($)		12 Months Ended
	Nov. 03, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants and awards under Stock Incentive Plans		4,500,000
Common stock, aggregate shares authorized		200,000,000	200,000,000
Stock-based compensation expense related to its stock incentive plans, ESPP and SPP		$ 34,000,000	$ 32,100,000	$ 31,700,000
Aggregate fair value of restricted and deferred stocks vested		$ 29,800,000	$ 31,600,000	$ 28,200,000
Weighted average grant-date fair value of restricted and deferred stock awards granted		$ 67.90	$ 70.44	$ 57.73
Aggregate intrinsic value of stock options exercised		$ 6,800,000	$ 11,300,000	$ 38,800,000
Excess tax benefit related to employee stock incentive plans		4,131,000	11,583,000	17,479,000
Cash proceeds received from the exercise of stock options		$ 4,700,000	$ 6,100,000	$ 30,100,000
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Unrecognized compensation expense related to options		$ 0
Stock Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of options, maximum years		10 years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Unrecognized compensation expense related to non-vested restricted stock, weighted-average period in years		1 year 6 months
Unrecognized compensation expense related to non-vested restricted shares		$ 28,500,000
1996 Non-Qualified Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of market value of common stock at which employees are permitted to purchase	85.00%
2015 Non-Qualified Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of market value of common stock at which employees are permitted to purchase	90.00%
1996 Non-Qualified Employee Stock Purchase Plan and 2015 Non-Qualified Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number Shares issued under Stock Purchase Plans		300,000
Common stock, aggregate shares authorized		2,600,000
Common stock, reserved for issuance		2,300,000

Stock Incentive Plans and Stock Purchase Plans - Schedule of Restricted Stock Awards (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Non-vested shares at January 1, 2016	1,013,791
Number of Shares, Awarded	504,943
Number of Shares, Forfeited	(52,957)
Number of Shares, Vested	(519,448)
Number of Shares, Non-vested shares at December 31, 2016	946,329	1,013,791
Weighted Average Fair Value, Non-vested shares at January 1, 2016	$ 61.50
Weighted Average Fair Value, Awarded	67.90	$ 70.44	$ 57.73
Weighted Average Fair Value, Forfeited	66.18
Weighted Average Fair Value, Vested	57.31
Weighted Average Fair Value, Non-vested shares at December 31, 2016	$ 66.98	$ 61.50

Stock Incentive Plans and Stock Purchase Plans - Schedule of Activity and Certain Other Information Related to Stock Option Awards (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding at January 1, 2016	585,387
Number of Shares, Exercised	(175,101)
Number of Shares, Outstanding at December 31, 2016	410,286	585,387
Number of Shares, Exercisable at December 31, 2016	410,286
Weighted Average Exercise Price, Outstanding at January 1, 2016	$ 27.96
Weighted Average Exercise Price, Exercised	27.08
Weighted Average Exercise Price, Outstanding at December 31, 2016	28.33	$ 27.96
Weighted Average Exercise Price, Exercisable at December 31, 2016	$ 28.33
Weighted Average Remaining Contractual Term (in years), Outstanding at December 31, 2016	2 years
Weighted Average Remaining Contractual Term (in years), Exercisable at December 31, 2016	2 years
Aggregate Intrinsic Value, Exercised	$ 6.8	$ 11.3	$ 38.8
Aggregate Intrinsic Value, Outstanding at December 31, 2016	15.7
Aggregate Intrinsic Value, Exercisable at December 31, 2016	$ 15.7

Common Stock Repurchase Programs - Additional Information (Detail) - USD ($)			1 Months Ended		12 Months Ended
	Mar. 16, 2015	Dec. 17, 2014	Oct. 31, 2015	Jul. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Oct. 31, 2014
Common Stock [Line Items]
Repurchased common stock, shares					900,000	3,400,000
Common stock repurchased					$ 61,828,000	$ 235,051,000	$ 488,429,000
Common stock authorized for repurchase									$ 600,000,000
Restricted Stock [Member]
Common Stock [Line Items]
Number of shares withheld to satisfy minimum statutory tax withholding obligations					46,490	18,282
Amount withheld to satisfy minimum statutory tax withholding obligations					$ 3,200,000	$ 1,500,000
Accelerated Share Repurchase (ASR) Agreements [Member]
Common Stock [Line Items]
Repurchased common stock, shares	2,200,000	2,500,000	300,000	300,000
Common stock repurchased	$ 200,000,000	$ 200,000,000
Common stock purchase							$ 200,000,000	$ 200,000,000

Commitments and Contingencies - Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2017	$ 35,465
2018	27,421
2019	19,791
2020	13,132
2021	8,960
Thereafter	17,602
Total	$ 122,371

Selected Quarterly Financial Information - Summary of Company's Selected Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net revenue	$ 830,770	$ 828,006	$ 771,759	$ 752,624	$ 741,740	$ 722,273	$ 676,588	$ 639,395	$ 3,183,159	$ 2,779,996	$ 2,438,913
Practice salaries and benefits	532,952	521,832	484,625	491,811	461,074	450,033	422,803	419,595	2,031,220	1,753,505	1,543,395
Practice supplies and other operating expenses	32,737	31,641	26,992	27,046	26,164	24,007	24,878	23,431	118,416	98,480	89,002
General and administrative expenses	97,049	93,457	92,116	89,950	85,393	80,185	72,401	67,936	372,572	305,915	247,527
Depreciation and amortization	25,254	24,185	20,241	19,584	18,149	16,918	15,549	13,612	89,264	64,228	45,990
Total operating expenses	687,992	671,115	623,974	628,391	590,780	571,143	535,631	524,574	2,611,472	2,222,128	1,925,914
Income from operations	142,778	156,891	147,785	124,233	150,960	151,130	140,957	114,821	571,687	557,868	512,999
Investment and other income	770	221	410	618	751	567	384	142	2,019	1,844	2,728
Interest expense	(16,356)	(17,215)	(15,058)	(14,463)	(8,493)	(6,201)	(5,149)	(3,267)	(63,092)	(23,110)	(8,891)
Equity in earnings of unconsolidated affiliate	806	796	789	794	777	784	745	821	3,185	3,127	1,780
Total non-operating expenses	(14,780)	(16,198)	(13,859)	(13,051)	(6,965)	(4,850)	(4,020)	(2,304)	(57,888)	(18,139)	(4,383)
Income before income taxes	127,998	140,693	133,926	111,182	143,995	146,280	136,937	112,517	513,799	539,729	508,616
Income tax provision	49,919	44,272	51,601	43,411	51,581	55,640	52,889	43,928	189,203	204,038	191,413
Net income	78,079	96,421	82,325	67,771	92,414	90,640	84,048	68,589	324,596	335,691	317,203
Net loss attributable to noncontrolling interests		88	102	128	288	141	82	118	318	629	78
Net income attributable to MEDNAX, Inc.	$ 78,079	$ 96,509	$ 82,427	$ 67,899	$ 92,702	$ 90,781	$ 84,130	$ 68,707	$ 324,914	$ 336,320	$ 317,281
Earnings per share, Basic	$ 0.84	$ 1.04	$ 0.89	$ 0.74	$ 1.00	$ 0.98	$ 0.91	$ 0.73	$ 3.52	$ 3.61	$ 3.22
Earnings per share, Diluted	$ 0.84	$ 1.04	$ 0.89	$ 0.73	$ 0.99	$ 0.97	$ 0.90	$ 0.72	$ 3.49	$ 3.58	$ 3.18
Weighted average shares, Basic	92,728	92,604	92,182	92,269	92,790	92,949	92,500	94,231	92,422	93,077	98,588
Weighted average shares, Diluted	93,347	93,146	92,945	93,091	93,536	93,646	93,495	95,325	93,109	93,960	99,887

Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Balance at beginning of year	$ 1,129,301	$ 848,767	$ 712,285
Amount charged against operating revenue	7,464,030	6,389,195	5,403,437
Accounts receivable contractual adjustments and write-offs (net of recoveries)	(7,368,965)	(6,108,661)	(5,266,955)
Balance at end of year	$ 1,224,366	$ 1,129,301	$ 848,767

General - Additional Information (Detail)	Dec. 31, 2016 States
Teleradiology [Member]
Organization Presentation And General [Line Items]
Number of states in which entity operates	50