Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014 Hospital Surgery_Center State	Sep. 30, 2013	Sep. 30, 2014 Hospital Surgery_Center State	Sep. 30, 2013
Accounting Policies [Abstract]
Number of owned and operated hospitals	165		165
Number of freestanding surgery centers	113		113
Number of facilities locations	20		20
General and administrative expense	$ 71	$ 76	$ 206	$ 207
Adjustments to Medicare revenues	94
Adjustment to Medicare revenues in diluted per share	$ 0.13
Adjustments to Medicaid revenues	68
Adjustment to Medicaid revenues in diluted per share	$ 0.09
Percentage of adjustment on claim amount	68.00%
Revenue increase	$ 26