Income Taxes Pretax Income (Loss) for Domestic and Foreign Operations Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Gains (Losses) on Extinguishment of Debt	$ (27)	$ (23)	$ (56)