Contingencies and Legal Claim Costs - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended			0 Months Ended
	Dec. 31, 2012 Hospital	Dec. 31, 2012 Y Hospital	Oct. 28, 2011 Cases	Dec. 31, 2003	Jan. 24, 2013 Pending Litigation [Member] Health Care Foundation of Greater Kansas City [Member]	Jul. 31, 2012 Florida [Member] Hospital
Schedule Of Activities Related To Claims Filed [Line Items]
Number of owned and operated hospitals reviewed	95	95				8
Number of claims filed			3
Capital commitments in connection with purchase of hospitals				$ 450
Legal claim costs	110	175
Judgment award by the court					$ 162
Period of agreed capital commitments		5 years
Number of year under court-supervisor accounting for expenditures following the purchase		10