Derivatives and Hedging - Interest Rate Risk Management (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Estimated pretax losses currently included within Accumulated Other Comprehensive Loss that will be reclassified to earnings in next twelve months	$ 7
(Loss) income on financial instruments	(24)	$ (15)	$ 18
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
(Loss) income on financial instruments	$ (8)	$ (18)	$ (18)