Segment Reporting (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net revenues		$ 2,855,168	$ 2,681,353	$ 5,659,559	$ 5,368,869
Total assets		11,752,650	11,069,417	11,752,650	11,069,417	$ 11,265,480
Behavioral Health Services
Segment Reporting Information [Line Items]
Net revenues	[1]	1,320,241	1,274,083	2,606,624	2,512,079
Total assets	[1]	6,933,825	6,746,272	6,933,825	6,746,272
Behavioral Health Services | Located in U.K.
Segment Reporting Information [Line Items]
Net revenues		144,000	119,000	281,000	234,000
Total assets		$ 1,217,000	$ 1,123,000	$ 1,217,000	$ 1,123,000

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $144 million and $119 million for the three-month periods ended June 30, 2019 and 2018, respectively, and approximately $281 million and $234 million for the six-month periods ended June 30, 2019 and 2018, respectively.  Total assets at our U.K. behavioral health care facilities were approximately $1.217 billion and $1.123 billion as of June 30, 2019 and 2018, respectively.