Segment Reporting (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net revenues		$ 2,804,391	$ 2,687,516
Total assets		11,721,277	11,023,517	$ 11,265,480
Behavioral Health Services
Segment Reporting Information [Line Items]
Net revenues	[1]	1,286,383	1,237,996
Total assets	[1]	6,972,929	6,649,732
Behavioral Health Services | Located in U.K.
Segment Reporting Information [Line Items]
Net revenues		137,000	115,000
Total assets		$ 1,237,000	$ 1,176,000

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $137 million and $115 million for the three-month periods ended March 31, 2019 and 2018, respectively. Total assets at our U.K. behavioral health care facilities were approximately $1.237 billion and $1.176 billion as of March 31, 2019 and 2018, respectively.