Interim Condensed Consolidated Financial Statements - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2012	Sep. 30, 2011
Interim Condensed Consolidated Financial Statements [Abstract]
Initial public offering of shares common stock				87,719,300
Initial public offering of shares of common stock, price per share				$ 30.00
Stockholders sold common stock in offering				57,410,700
Investor final fee upon completion of initial public offering of common stock		$ 181
Number of owned and operated hospitals	162				162
Number of freestanding surgery centers					112
Number of states facilities are located in					20
General and administrative expense	62		53		174	162
Increase of revenues					188
Additional Medicare payments					271
Reduction in Medicare revenues					83
Adjustment and related expenses added to income before income taxes					170
Adjustment and related expenses added to income before income taxes in diluted per share					$ 0.22
Electronic health record incentive income	131		51		256	90
Medicaid And Medicare [Member]
Interim Condensed Consolidated Financial Statements [Abstract]
Electronic health record incentive income			$ 51			$ 90