Derivatives (Hedges of Net Investments in Foreign Operations) (Details) - Foreign Operations Hedges [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in AOCI (Effective Portion)	$ (326)	$ (399)
Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in AOCI (Effective Portion)	(95)	(231)
Currency options
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in AOCI (Effective Portion)	$ (231)	$ (168)