Financial Information for the Company and Its Subsidiaries - Summary of Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating activities:
Net income (loss)	$ 55,591	$ 33,844	$ 80,960	$ 48,438
Adjustments to reconcile net income (loss) to net cash (used in) provided by continuing operating activities:
Depreciation and amortization	36,752	14,926	64,727	28,030
Amortization of debt issuance costs			4,956	3,218
Equity-based compensation expense	6,888	5,355	13,844	9,249
Deferred income tax (benefit) expense			16,821	24,682
Loss from discontinued operations, net of taxes		(1)		(3)
Loss (gain) on foreign currency derivatives	(98)	961	(508)	908
Other			704	692
Change in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net			(18,982)	(10,442)
Other current assets			(7,256)	(13,048)
Other assets			1,582	(1,218)
Accounts payable and other accrued liabilities			29,101	(4,313)
Accrued salaries and benefits			(3,846)	(225)
Other liabilities			3,728	4,619
Net cash (used in) provided by continuing operating activities			185,831	90,587
Net cash (used in) provided by discontinued operating activities			(2,973)	554
Net cash (used in) provided by operating activities			182,858	91,141
Investing activities:
Cash paid for acquisitions, net of cash acquired			(683,285)	(286,734)
Cash paid for capital expenditures			(177,718)	(122,035)
Cash paid for real estate acquisitions			(28,439)	(3,428)
Settlement of foreign currency derivatives			508	(908)
Other			(1,084)	(481)
Net cash used in investing activities			(890,018)	(413,586)
Financing activities:
Borrowings on long-term debt			1,480,000	875,000
Borrowings on revolving credit facility			158,000	180,000
Principal payments on revolving credit facility			(166,000)	(180,000)
Principal payments on long-term debt			(29,869)	(15,875)
Repayment of assumed CRC debt			(1,348,389)	(904,467)
Payment of debt issuance costs			(35,511)	(22,775)
Issuance of Common Stock			685,097	331,530
Common stock withheld for minimum statutory taxes, net			(7,365)	(7,826)
Excess tax benefit from equity awards				6,327
Other			(823)	(150)
Net cash provided by financing activities			735,140	261,764
Effect of exchange rate changes on cash			(8,479)	1,213
Net (decrease) increase in cash and cash equivalents			19,501	(59,468)
Cash and cash equivalents at beginning of the period			11,215	94,040
Cash and cash equivalents at end of the period	30,716	34,572	30,716	34,572
Consolidating Adjustments [Member]
Operating activities:
Net income (loss)	(67,943)	(50,281)	(108,812)	(76,268)
Adjustments to reconcile net income (loss) to net cash (used in) provided by continuing operating activities:
Equity in earnings of subsidiaries	67,943	50,281	108,812	76,268
Change in operating assets and liabilities, net of effect of acquisitions:
Other assets			755	300
Net cash (used in) provided by continuing operating activities			775	300
Net cash (used in) provided by operating activities			775	300
Financing activities:
Principal payments on long-term debt			775	300
Cash (used in) provided by intercompany activity			(1,550)	(600)
Net cash provided by financing activities			(775)	(300)
Parent [Member]
Operating activities:
Net income (loss)	55,591	33,844	80,960	48,438
Adjustments to reconcile net income (loss) to net cash (used in) provided by continuing operating activities:
Equity in earnings of subsidiaries	(67,943)	(50,281)	(108,812)	(76,268)
Amortization of debt issuance costs			5,171
Equity-based compensation expense			13,844	9,249
Deferred income tax (benefit) expense				(798)
Loss (gain) on foreign currency derivatives	(98)	961	(508)	908
Change in operating assets and liabilities, net of effect of acquisitions:
Other assets			(775)	(300)
Net cash (used in) provided by continuing operating activities			(10,120)	(18,771)
Net cash (used in) provided by operating activities			(10,120)	(18,771)
Financing activities:
Borrowings on long-term debt			1,480,000	875,000
Borrowings on revolving credit facility			158,000	180,000
Principal payments on revolving credit facility			(166,000)	(180,000)
Principal payments on long-term debt			(29,869)	(15,875)
Repayment of assumed CRC debt			(1,348,389)	(904,467)
Payment of debt issuance costs			(35,511)
Issuance of Common Stock			685,097
Common stock withheld for minimum statutory taxes, net			(7,365)
Cash (used in) provided by intercompany activity			(725,843)	64,113
Net cash provided by financing activities			10,120	18,771
Combined Subsidiary Guarantors [Member]
Operating activities:
Net income (loss)	40,763	42,628	67,071	59,054
Adjustments to reconcile net income (loss) to net cash (used in) provided by continuing operating activities:
Depreciation and amortization	14,216	10,551	26,967	19,262
Amortization of debt issuance costs				3,438
Deferred income tax (benefit) expense			18,420	22,964
Loss from discontinued operations, net of taxes		(1)		(3)
Other			720	662
Change in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net			(24,072)	(11,409)
Other current assets			(1,459)	(12,026)
Other assets			1,327	(1,220)
Accounts payable and other accrued liabilities			21,943	5,991
Accrued salaries and benefits			9,230	791
Other liabilities			7,208	5,442
Net cash (used in) provided by continuing operating activities			127,355	92,946
Net cash (used in) provided by discontinued operating activities			(2,973)	554
Net cash (used in) provided by operating activities			124,382	93,500
Investing activities:
Cash paid for acquisitions, net of cash acquired			(103,189)	(89,041)
Cash paid for capital expenditures			(99,157)	(62,101)
Cash paid for real estate acquisitions			(16,638)	(3,428)
Settlement of foreign currency derivatives			508	(908)
Other			(1,084)	(481)
Net cash used in investing activities			(219,560)	(155,959)
Financing activities:
Payment of debt issuance costs				(22,775)
Issuance of Common Stock				331,530
Common stock withheld for minimum statutory taxes, net				(7,826)
Excess tax benefit from equity awards				6,327
Other			(823)	(150)
Cash (used in) provided by intercompany activity			104,062	(305,366)
Net cash provided by financing activities			103,239	1,740
Effect of exchange rate changes on cash				1,213
Net (decrease) increase in cash and cash equivalents			8,061	(59,506)
Cash and cash equivalents at beginning of the period			1,987	76,685
Cash and cash equivalents at end of the period	10,048	17,179	10,048	17,179
Combined Non-Guarantors [Member]
Operating activities:
Net income (loss)	27,180	7,653	41,741	17,214
Adjustments to reconcile net income (loss) to net cash (used in) provided by continuing operating activities:
Depreciation and amortization	22,536	4,375	37,760	8,768
Amortization of debt issuance costs			(215)	(220)
Deferred income tax (benefit) expense			(1,599)	2,516
Other			(16)	30
Change in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net			5,090	967
Other current assets			(5,797)	(1,022)
Other assets			255	2
Accounts payable and other accrued liabilities			7,158	(10,304)
Accrued salaries and benefits			(13,076)	(1,016)
Other liabilities			(3,480)	(823)
Net cash (used in) provided by continuing operating activities			67,821	16,112
Net cash (used in) provided by operating activities			67,821	16,112
Investing activities:
Cash paid for acquisitions, net of cash acquired			(580,096)	(197,693)
Cash paid for capital expenditures			(78,561)	(59,934)
Cash paid for real estate acquisitions			(11,801)
Net cash used in investing activities			(670,458)	(257,627)
Financing activities:
Principal payments on long-term debt			(775)	(300)
Cash (used in) provided by intercompany activity			623,331	241,853
Net cash provided by financing activities			622,556	241,553
Effect of exchange rate changes on cash			(8,479)
Net (decrease) increase in cash and cash equivalents			11,440	38
Cash and cash equivalents at beginning of the period			9,228	17,355
Cash and cash equivalents at end of the period	$ 20,668	$ 17,393	$ 20,668	$ 17,393