Segment Reporting (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Net revenues	$ 4,283,816	$ 3,907,604	$ 8,383,536	$ 7,751,186
Total assets	14,985,577		14,985,577		$ 14,469,749
Behavioral Health Services
Segment Reporting Information [Line Items]
Net revenues	1,880,076	1,726,032	3,627,725	3,382,099
Behavioral Health Services | Located in U.K.
Segment Reporting Information [Line Items]
Net revenues	$ 247,000	$ 213,000	$ 474,000	$ 421,000