Schedule of Disaggregates Revenue by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation Of Revenue [Line Items]
Net revenues	$ 4,099,720	$ 3,843,582
Percentage of Net Revenue	100.00%	100.00%
Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 468,039	$ 425,903
Percentage of Net Revenue	11.00%	11.00%
Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 520,299	$ 469,475
Percentage of Net Revenue	13.00%	12.00%
Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 526,908	$ 483,225
Percentage of Net Revenue	13.00%	13.00%
Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 602,829	$ 582,667
Percentage of Net Revenue	15.00%	15.00%
Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues	$ 1,184,801	$ 1,102,958
Percentage of Net Revenue	29.00%	29.00%
UK Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 227,068	$ 207,796
Percentage of Net Revenue	6.00%	5.00%
Other Patient Revenue and Adjustments, Net
Disaggregation Of Revenue [Line Items]
Net revenues	$ 310,073	$ 267,464
Percentage of Net Revenue	8.00%	7.00%
Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 259,703	$ 304,094
Percentage of Net Revenue	6.00%	8.00%
Acute Care Hospital Services
Disaggregation Of Revenue [Line Items]
Net revenues	$ 2,349,229	$ 2,185,081
Percentage of Net Revenue	100.00%	100.00%
Acute Care Hospital Services | Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 391,561	$ 349,087
Percentage of Net Revenue	17.00%	16.00%
Acute Care Hospital Services | Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 419,862	$ 373,401
Percentage of Net Revenue	18.00%	17.00%
Acute Care Hospital Services | Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 250,865	$ 234,862
Percentage of Net Revenue	11.00%	11.00%
Acute Care Hospital Services | Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 158,414	$ 159,359
Percentage of Net Revenue	7.00%	7.00%
Acute Care Hospital Services | Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues	$ 780,148	$ 698,785
Percentage of Net Revenue	33.00%	32.00%
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	$ 149,226	$ 123,333
Percentage of Net Revenue	6.00%	6.00%
Acute Care Hospital Services | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 199,153	$ 246,254
Percentage of Net Revenue	8.00%	11.00%
Behavioral Health Services
Disaggregation Of Revenue [Line Items]
Net revenues	$ 1,747,649	$ 1,656,067
Percentage of Net Revenue	100.00%	100.00%
Behavioral Health Services | Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 76,478	$ 76,816
Percentage of Net Revenue	4.00%	5.00%
Behavioral Health Services | Managed Medicare
Disaggregation Of Revenue [Line Items]
Net revenues	$ 100,437	$ 96,074
Percentage of Net Revenue	6.00%	6.00%
Behavioral Health Services | Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 276,043	$ 248,363
Percentage of Net Revenue	16.00%	15.00%
Behavioral Health Services | Managed Medicaid
Disaggregation Of Revenue [Line Items]
Net revenues	$ 444,415	$ 423,308
Percentage of Net Revenue	25.00%	26.00%
Behavioral Health Services | Managed Care (HMO and PPOs)
Disaggregation Of Revenue [Line Items]
Net revenues	$ 404,653	$ 404,173
Percentage of Net Revenue	23.00%	24.00%
Behavioral Health Services | UK Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 227,068	$ 207,796
Percentage of Net Revenue	13.00%	13.00%
Behavioral Health Services | Other Patient Revenue and Adjustments, Net
Disaggregation Of Revenue [Line Items]
Net revenues	$ 160,847	$ 144,131
Percentage of Net Revenue	9.00%	9.00%
Behavioral Health Services | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 57,708	$ 55,406
Percentage of Net Revenue	3.00%	3.00%
Other
Disaggregation Of Revenue [Line Items]
Net revenues	$ 2,842	$ 2,434
Other | Other Non-patient Revenue
Disaggregation Of Revenue [Line Items]
Net revenues	$ 2,842	$ 2,434