Revenue - Schedule of Revenue Attributed to Each Category (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 616,653	$ 551,199
U.S. Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	616,653	551,199
U.S. Facilities [Member] | Acute Inpatient Psychiatric Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	310,748	267,359
U.S. Facilities [Member] | Specialty Treatment Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	233,640	211,757
U.S. Facilities [Member] | Residential Treatment Centers [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 72,265	68,649
U.S. Facilities [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue		$ 3,434