Segment Reporting (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Total net revenues		$ 4,283,816	$ 3,907,604	$ 8,383,536	$ 7,751,186
Salaries, wages and benefits		2,014,951	1,856,372	3,966,055	3,698,996
Other segment item operating expenses		1,162,566	1,043,116	2,268,318	2,075,286
Depreciation and amortization expense		152,004	147,480	300,349	288,483
Other (income) expense, net		(8,479)	5,493	(14,138)	5,343
Reportable segment income before income taxes		473,385	382,006	893,813	718,092
Interest expense, net		35,364	48,899	75,420	101,725
Operating Segments
Segment Reporting Information [Line Items]
Total net revenues		4,281,110	3,904,718	8,377,988	7,745,866
Material Reconciling Items
Segment Reporting Information [Line Items]
Total net revenues		2,706	2,886	5,548	5,320
Reportable segment income before income taxes		623,932	572,200	1,222,148	1,097,606
Corporate Nonsegment
Segment Reporting Information [Line Items]
Total net revenues		2,706	2,886	5,548	5,320
Other segment item operating expenses	[1]	124,106	139,350	264,584	280,713
Other (income) expense, net		(6,726)	6,825	(3,293)	6,717
Reportable segment income before income taxes		473,385	382,006	893,813	718,092
Interest expense, net		35,873	46,905	72,592	97,404
Acute Care Hospital Services
Segment Reporting Information [Line Items]
Total net revenues		2,401,034	2,178,686	4,750,263	4,363,767
Acute Care Hospital Services | Operating Segments
Segment Reporting Information [Line Items]
Total net revenues		2,401,034	2,178,686	4,750,263	4,363,767
Acute Care Hospital Services | Material Reconciling Items
Segment Reporting Information [Line Items]
Salaries, wages and benefits		937,105	859,147	1,847,829	1,720,694
Other segment item operating expenses	[2]	1,142,344	1,011,953	2,231,416	2,037,773
Depreciation and amortization expense		96,370	94,361	191,017	184,673
Interest (income) expense, net		(1,613)	986	649	2,286
Other (income) expense, net		(916)	(461)	(9,183)	173
Reportable segment income before income taxes		227,744	212,700	488,535	418,168
Behavioral Health Services
Segment Reporting Information [Line Items]
Total net revenues		1,880,076	1,726,032	3,627,725	3,382,099
Behavioral Health Services | Operating Segments
Segment Reporting Information [Line Items]
Total net revenues	[3]	1,880,076	1,726,032	3,627,725	3,382,099
Behavioral Health Services | Material Reconciling Items
Segment Reporting Information [Line Items]
Salaries, wages and benefits	[3]	977,156	895,494	1,905,322	1,767,690
Other segment item operating expenses	[2],[3]	453,206	420,423	883,606	836,133
Depreciation and amortization expense	[3]	53,259	50,478	104,667	98,350
Interest (income) expense, net	[3]	1,104	1,008	2,179	2,035
Other (income) expense, net	[3]	(837)	(871)	(1,662)	(1,547)
Reportable segment income before income taxes	[3]	396,188	359,500	733,613	679,438
Other
Segment Reporting Information [Line Items]
Total net revenues		$ 2,706	$ 2,886	$ 5,548	$ 5,320

[1] Non-segment operating expenses for each period includes salaries, wages and benefits, other operating expenses, supplies expense and lease and rental expense.

[2] Other segment operating expenses for each period includes other operating expenses, supplies expense and lease and rental expense.

[3] Includes net revenues generated from our behavioral health care facilities located in the U.K. amounting to approximately $247 million and $213 million for the three-month periods ended June 30, 2025 and 2024, respectively, and approximately $474 million and $421 million for the six-month periods ended June 30, 2025 and 2024, respectively.