Derivatives and Hedging Activities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	$ 922	$ 991
Total fair value of derivatives liabilties	218	164
Other Assets [Member]
Derivative [Line Items]
Total derivative assets, net	485	711
Derivatives, Fair Value [Line Items]
Cash collateral netting	(307)	(158)
Derivative asset and liability netting	(130)	(122)
Total derivative assets, net	485	711
Other Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	776	806
Other Assets [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	146	185
Other Liabilities [Member]
Derivative [Line Items]
Total derivative liabilities, net	88	38
Derivatives, Fair Value [Line Items]
Cash collateral netting	0	(4)
Derivative asset and liability netting	(130)	(122)
Total derivative liabilities, net	88	38
Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilties	102	50
Other Liabilities [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilties	116	114
Fair Value Hedging [Member] | Other Assets [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	391	314
Fair Value Hedging [Member] | Other Liabilities [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilties	0	4
Net Investment Hedging [Member] | Other Assets [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	385	492
Net Investment Hedging [Member] | Other Liabilities [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilties	102	46
Risk Exposure Low [Member]
Derivative [Line Items]
Total derivative assets, net	0
Total derivative liabilities, net	0	0
Derivatives, Fair Value [Line Items]
Total derivative assets, net	0
Total derivative liabilities, net	0	0
Individually Significant Counterparties [Member]
Derivative [Line Items]
Total derivative assets, net	0	0
Total derivative liabilities, net	0	0
Derivatives, Fair Value [Line Items]
Total derivative assets, net	0	0
Total derivative liabilities, net	$ 0	$ 0