Income Taxes (Income Tax Contingency and Taxes Paid Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Contingency [Abstract]
Unrecognized benefit that would affect the effective tax rate	$ 9
Amount of interest and penalties included in liabilities for uncertain tax positions	$ 3
Effective Income Tax Rate, Continuing Operations	0.00%	41.30%
Effective Income Tax Rate, Continuing Operations, Including Net Income from Noncontrolling Interests	0.00%	68.40%
Current provision for income taxes	$ 16
Cash Paid for Income Taxes, Net of Refunds Received [Abstract]
Cash paid for income taxes (refunds received), net	0	$ 0
Certain Hospitals [Member]
Income Tax Contingency [Abstract]
Impairment of long-lived assets held for sale	$ 250