Acquisitions and Divestitures (Schedule of Net Operating Revenues and Income (Loss) and Assets and Liabilities Classified as Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Acquisitions And Divestitures [Abstract]
Net operating revenues	$ 17	$ 114	$ 73	$ 203
Loss from operations of entities sold or held for sale before income taxes	(10)	(2)	(27)	(6)
Impairment of hospitals sold or held for sale		(5)	(2)	(29)
Loss on sale, net			(1)
Loss from discontinued operations, before taxes	(10)	(7)	(30)	(35)
Income tax benefit	(4)	(1)	(10)	(7)
Loss from discontinued operations, net of taxes	$ (6)	$ (6)	$ (20)	$ (28)