Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Gross inpatient revenues	$ 5,485,263	$ 5,083,418
Gross outpatient revenues	2,150,120	1,848,225
Total net revenues	1,920,166	1,831,632
Income/(loss) before allocation of corporate overhead and income taxes	235,783	203,984
Allocation of corporate overhead	0	0
Income/(loss) after allocation of corporate overhead and before income taxes	235,783	203,984
Total assets	8,431,385	8,316,508	8,311,723
Acute Care Hospital Services
Segment Reporting Information [Line Items]
Gross inpatient revenues	3,876,364	3,507,270
Gross outpatient revenues	1,957,491	1,651,575
Total net revenues	971,391	908,734
Income/(loss) before allocation of corporate overhead and income taxes	111,650	80,629
Allocation of corporate overhead	(44,697)	(46,112)
Income/(loss) after allocation of corporate overhead and before income taxes	66,953	34,517
Total assets	3,200,203	3,077,881
Behavioral Health Services
Segment Reporting Information [Line Items]
Gross inpatient revenues	1,608,899	1,576,148
Gross outpatient revenues	184,115	185,802
Total net revenues	945,457	909,544
Income/(loss) before allocation of corporate overhead and income taxes	221,148	220,775
Allocation of corporate overhead	(26,169)	(22,367)
Income/(loss) after allocation of corporate overhead and before income taxes	194,979	198,408
Total assets	5,004,478	4,963,760
Other
Segment Reporting Information [Line Items]
Gross outpatient revenues	8,514	10,848
Total net revenues	3,318	13,354
Income/(loss) before allocation of corporate overhead and income taxes	(97,015)	(97,420)
Allocation of corporate overhead	70,866	68,479
Income/(loss) after allocation of corporate overhead and before income taxes	(26,149)	(28,941)
Total assets	$ 226,704	$ 274,867