Contingencies and Legal Claim Costs - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended		3 Months Ended		9 Months Ended		0 Months Ended	3 Months Ended		9 Months Ended
	Apr. 25, 2014	Oct. 28, 2011 Cases	Mar. 31, 2014	Dec. 31, 2012	Sep. 30, 2014 Hospital	Oct. 31, 2009	Jan. 24, 2013 Pending Litigation [Member] Health Care Foundation of Greater Kansas City [Member]	Mar. 31, 2014 Pending Litigation [Member] Health Care Foundation of Greater Kansas City [Member]	Dec. 31, 2012 Pending Litigation [Member] Health Care Foundation of Greater Kansas City [Member]	Sep. 30, 2014 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						8
Number of claims filed		3
Capital commitments in connection with purchase of hospitals						$ 450
Additional shortfall related to capital expenditures	78
Legal claim costs			78	175	78
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 years
Plaintiff attorneys fees award										$ 12
Percentage of legal claim costs								9.00%	9.00%