Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Gross inpatient revenues									$ 18,170,937	$ 17,277,976	$ 13,187,274
Gross outpatient revenues									6,828,975	6,091,262	4,995,754
Total net revenues	1,764,927	1,680,353	1,723,084	1,793,036	1,662,996	1,662,675	1,711,255	1,723,296	6,961,400	6,760,222	4,900,147
Income (loss) before allocation of corporate overhead and income taxes									763,663	696,336	428,097
Allocation of corporate overhead									0	0	0
Income (loss) after allocation of corporate overhead and before income taxes									763,663	696,336	428,097
Total assets	8,200,843				7,665,245				8,200,843	7,665,245	7,527,936
Acute Care Hospital Services
Segment Reporting Information [Line Items]
Gross inpatient revenues									12,406,567	11,770,248	10,623,407
Gross outpatient revenues									6,134,615	5,431,146	4,596,317
Total net revenues									3,461,416	3,423,957	3,272,488
Income (loss) before allocation of corporate overhead and income taxes									337,385	352,931	352,334
Allocation of corporate overhead									(162,056)	(131,225)	(128,588)
Income (loss) after allocation of corporate overhead and before income taxes									175,329	221,706	223,746
Total assets	2,984,169				2,782,102				2,984,169	2,782,102	2,681,803
Behavioral Health Services
Segment Reporting Information [Line Items]
Gross inpatient revenues									5,764,370	5,507,728	2,563,867
Gross outpatient revenues									646,177	606,876	350,192
Total net revenues									3,460,141	3,308,862	1,597,022
Income (loss) before allocation of corporate overhead and income taxes									838,603	729,142	353,046
Allocation of corporate overhead									(84,597)	(62,710)	(43,362)
Income (loss) after allocation of corporate overhead and before income taxes									754,006	666,432	309,684
Total assets	4,979,965				4,373,379				4,979,965	4,373,379	4,360,262
Other
Segment Reporting Information [Line Items]
Gross outpatient revenues									48,183	53,240	49,245
Total net revenues									39,843	27,403	30,637
Income (loss) before allocation of corporate overhead and income taxes									(412,325)	(385,737)	(277,283)
Allocation of corporate overhead									246,653	193,935	171,950
Income (loss) after allocation of corporate overhead and before income taxes									(165,672)	(191,802)	(105,333)
Total assets	$ 236,709				$ 509,764				$ 236,709	$ 509,764	$ 485,871