Derivatives and Hedging Activities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Total derivative assets, gross	$ 343	$ 514
Total derivative liabilities, gross	440	214
Derivative asset and derivative liability netting, assets	(90)	(90)
Derivative asset and derivative liability netting, liabilities	(90)	(90)
Cash collateral netting, assets	(185)	(28)
Cash collateral netting, liabilities	(9)	(78)
Total derivatives assets, net	68	396
Total derivatives liabilities, net	341	46
Other Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets, gross	209	256
Other Assets [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets, gross	185	34
Other Assets [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets, gross	24	222
Other Assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets, gross	134	258
Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative liabilities, gross	186	135
Other Liabilities [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative liabilities, gross	0	74
Other Liabilities [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative liabilities, gross	186	61
Other Liabilities [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivative liabilities, gross	$ 254	$ 79