Segment Reporting (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Net revenues		$ 3,963,027	$ 3,562,774	$ 11,714,213	$ 10,578,430
Total assets		14,353,848	13,873,470	14,353,848	13,873,470	$ 13,967,602
Behavioral Health Services
Segment Reporting Information [Line Items]
Net revenues	[1]	1,714,914	1,542,695	5,102,290	4,575,378
Total assets	[1]	7,631,827	7,372,995	7,631,827	7,372,995
Behavioral Health Services | Located in U.K.
Segment Reporting Information [Line Items]
Net revenues		230,000	203,000	651,000	561,000
Total assets		$ 1,442,000	$ 1,260,000	$ 1,442,000	$ 1,260,000

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $230 million and $203 million for the three-month periods ended September 30, 2024 and 2023, respectively, and approximately $651 million and $561 million for the nine-month periods ended September 30, 2024 and 2023, respectively. Total assets at our U.K. behavioral health care facilities were approximately $1.442 billion and $1.260 billion as of September 30, 2024 and 2023, respectively.