Schedule of Disaggregates Revenue by Major Source (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Net revenues		$ 3,467,518	$ 3,292,956
Percentage of Net Revenue		100.00%	100.00%
Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 405,990	$ 416,621
Percentage of Net Revenue		12.00%	13.00%
Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 419,109	$ 396,098
Percentage of Net Revenue		12.00%	12.00%
Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 316,482	$ 331,239
Percentage of Net Revenue		9.00%	10.00%
Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 591,249	$ 505,802
Percentage of Net Revenue		17.00%	15.00%
Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues		$ 1,046,092	$ 1,004,100
Percentage of Net Revenue		30.00%	30.00%
UK Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 167,789	$ 176,092
Percentage of Net Revenue		5.00%	5.00%
Other Patient Revenue and Adjustments, Net
Disaggregation Of Revenue [Line Items]
Net revenues		$ 242,634	$ 212,843
Percentage of Net Revenue		7.00%	6.00%
Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 278,173	$ 250,161
Percentage of Net Revenue		8.00%	8.00%
Acute Care Hospital Services
Disaggregation Of Revenue [Line Items]
Net revenues		$ 1,973,532	$ 1,912,316
Percentage of Net Revenue		100.00%	100.00%
Acute Care Hospital Services | Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 329,446	$ 337,109
Percentage of Net Revenue		17.00%	18.00%
Acute Care Hospital Services | Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 344,032	$ 332,248
Percentage of Net Revenue		17.00%	17.00%
Acute Care Hospital Services | Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 110,009	$ 155,836
Percentage of Net Revenue		6.00%	8.00%
Acute Care Hospital Services | Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 192,298	$ 171,637
Percentage of Net Revenue		10.00%	9.00%
Acute Care Hospital Services | Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues		$ 654,795	$ 638,895
Percentage of Net Revenue		33.00%	33.00%
Acute Care Hospital Services | UK Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 0	$ 0
Percentage of Net Revenue		0.00%	0.00%
Acute Care Hospital Services | Other Patient Revenue and Adjustments, Net
Disaggregation Of Revenue [Line Items]
Net revenues		$ 120,957	$ 92,110
Percentage of Net Revenue		6.00%	5.00%
Acute Care Hospital Services | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 221,995	$ 184,481
Percentage of Net Revenue		11.00%	10.00%
Behavioral Health Services
Disaggregation Of Revenue [Line Items]
Net revenues	[1]	$ 1,490,489	$ 1,366,467
Percentage of Net Revenue		100.00%	100.00%
Behavioral Health Services | Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 76,544	$ 79,512
Percentage of Net Revenue		5.00%	6.00%
Behavioral Health Services | Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues		$ 75,077	$ 63,850
Percentage of Net Revenue		5.00%	5.00%
Behavioral Health Services | Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 206,473	$ 175,403
Percentage of Net Revenue		14.00%	13.00%
Behavioral Health Services | Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues		$ 398,951	$ 334,165
Percentage of Net Revenue		27.00%	24.00%
Behavioral Health Services | Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues		$ 391,297	$ 365,205
Percentage of Net Revenue		26.00%	27.00%
Behavioral Health Services | UK Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 167,789	$ 176,092
Percentage of Net Revenue		11.00%	13.00%
Behavioral Health Services | Other Patient Revenue and Adjustments, Net
Disaggregation Of Revenue [Line Items]
Net revenues		$ 121,677	$ 120,733
Percentage of Net Revenue		8.00%	9.00%
Behavioral Health Services | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 52,681	$ 51,507
Percentage of Net Revenue		4.00%	4.00%
Other
Disaggregation Of Revenue [Line Items]
Net revenues		$ 3,497	$ 14,173
Other | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues		$ 3,497	$ 14,173

[1] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $168 million and $176 million for the three-month periods ended March 31, 2023 and 2022, respectively. Total assets at our U.K. behavioral health care facilities were approximately $1.265 billion and $1.320 billion as of March 31, 2023 and 2022, respectively.