Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Revenues	$ 3,297,035	$ 2,954,083
Income from continuing operations before income taxes:
Income from continuing operations before income taxes	145,537	135,697
Hospital operations [Member]
Revenues:
Revenues	3,223,098	2,884,330
Income from continuing operations before income taxes:
Income from continuing operations before income taxes	200,308	178,113
Corporate and all other [Member]
Revenues:
Revenues	73,937	69,753
Income from continuing operations before income taxes:
Income from continuing operations before income taxes	$ (54,771)	$ (42,416)