Summary of Significant Accounting Policies (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenue Recognition
Fee-for-service revenue, net of contractuals	$ 1,545,317	$ 1,315,487	$ 3,019,853	$ 2,584,951
Subsidies and fees	144,488	128,644	275,200	266,970
Revenue, net of contractuals	1,689,805	1,444,131	3,295,053	2,851,921
Provision for uncompensated care	(790,550)	(643,033)	(1,507,474)	(1,244,529)
Net revenue	899,255	801,098	1,787,579	1,607,392
Medicare
Revenue Recognition
Fee-for-service revenue, net of contractuals	235,906	189,490	469,780	382,200
Medicaid
Revenue Recognition
Fee-for-service revenue, net of contractuals	51,849	47,217	103,063	93,327
Commercial insurance and managed care
Revenue Recognition
Fee-for-service revenue, net of contractuals	568,527	515,529	1,128,718	1,017,628
Self-pay
Revenue Recognition
Fee-for-service revenue, net of contractuals	$ 689,035	$ 563,251	$ 1,318,292	$ 1,091,796
Minimum | Self-pay
Revenue Recognition
Treatment period			30 days
Bills and notifications period			90 days
Maximum | Self-pay
Revenue Recognition
Treatment period			60 days
Bills and notifications period			120 days