Segment Reporting (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net revenues		$ 2,822,453	$ 2,648,913	$ 8,482,012	$ 8,017,782
Total assets		11,594,401	11,273,585	11,594,401	11,273,585	$ 11,265,480
Behavioral Health Services
Segment Reporting Information [Line Items]
Net revenues	[1]	1,291,816	1,262,472	3,898,440	3,774,551
Total assets	[1]	6,919,100	6,871,765	6,919,100	6,871,765
Behavioral Health Services | Located in U.K.
Segment Reporting Information [Line Items]
Net revenues		135,000	130,000	415,000	364,000
Total assets		$ 1,175,000	$ 1,231,000	$ 1,175,000	$ 1,231,000

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $135 million and $130 million for the three-month periods ended September 30, 2019 and 2018, respectively, and approximately $415 million and $364 million for the nine-month periods ended September 30, 2019 and 2018, respectively.  Total assets at our U.K. behavioral health care facilities were approximately $1.175 billion and $1.231 billion as of September 30, 2019 and 2018, respectively.