Derivative Instruments and Hedging Activities (Derivative Instruments Used in Net Investment Hedge Accounting Relationships) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Cumulative Translation Adjustment, Net of Tax, Period Increase (Decrease)	$ 2	$ 16	$ 9	$ (56)
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	(1)	0	(6)	(130)
Foreign Exchange Contract [Member] | Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	(4)
Net Investment Hedges - Total Other Income, Net of Losses	0	0	0	(4)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	2	15	(4)	35
Other Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	(1)	1	(4)	9
Other Income [Member] | Revaluation of Foreign-Denominated Debt or Receivable [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 1	$ 1	$ 4	$ 134