Dispositions and Acquisitions (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended			9 Months Ended		1 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Oct. 31, 2012 Ascend Health Corporation [Member] States Facilities	Sep. 30, 2011 Acute Care Hospital Services [Member]	Sep. 30, 2012 Hospital San Juan Capestrano [Member] Beds	Oct. 31, 2012 Auburn Regional Medical Center [Member] Beds	Sep. 30, 2012 Peak Behavioral Health Services [Member]	Dec. 31, 2011 Peak Behavioral Health Services [Member]	Oct. 31, 2012 Peak Behavioral Health Services [Member] Beds
Significant Acquisitions and Disposals [Line Items]
Business acquisition, cash paid			$ 500
Number of psychiatric inpatient facilities			9
Number of states facilities located			5
Aggregate cash proceeds from divestiture of businesses					56	93	14	14
Number of acute care hospital beds included in sale					108	159			104
Net cash proceeds from the sale of a closed acute care hospital				24
Dispositions and Acquisitions (Textual) [Abstract]
Acquisition of a physician practice and various real properties	25
Return of deposit on terminated purchase agreement	6.5
Payment to acquire administrative office buildings		$ 9