Acquisitions - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 2,200,659	$ 2,199,937
CenterPointe Behavioral Health System, LLC [Member]
Business Acquisition [Line Items]
Cash		5,640
Accounts receivable, net		9,697
Other current assets		2,087
Property and equipment		35,670
Goodwill		97,844
Intangible assets		825
Deferred tax assets		1,573
Operating lease right-of-use assets		29,245
Total assets acquired		182,581
Accounts payable		3,820
Accrued salaries and benefits		3,585
Current portion of operating lease liabilities		2,569
Other accrued liabilities		1,277
Operating lease liabilities		26,675
Total liabilities assumed		37,926
Net assets acquired		$ 144,655