Segment Information (Schedule of Segment Reporting Information by Segment) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net operating revenues	$ 3,059	$ 3,666	$ 4,144	$ 4,486	$ 4,469	$ 4,380	$ 4,590	$ 4,999	$ 15,353	$ 18,438	$ 19,437
Loss from continuing operations before income taxes	(2,379)	$ (147)	$ (131)	$ (176)	(152)	$ (83)	$ (1,543)	$ 63	(2,833)	(1,715)	411
Expenditures for segment assets									564	744	953
Total assets	$ 17,450				21,944				$ 17,450	21,944
Hospital Operations [Member]
Segment Reporting Information [Line Items]
Net operating revenues										18,210	19,234
Loss from continuing operations before income taxes										(1,418)	767
Expenditures for segment assets										727	915
Total assets					20,582					20,582
Corporate and All Other Reporting Units [Member]
Segment Reporting Information [Line Items]
Net operating revenues										228	203
Loss from continuing operations before income taxes										(297)	(356)
Expenditures for segment assets										17	$ 38
Total assets					$ 1,362					$ 1,362