Derivatives and Hedging Activities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Total fair value of derivative assets	$ 127	$ 277
Total fair value of derivative liabilities	80	16
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset and liability netting	(43)	(11)
Total derivative assets, net	84	266
Other Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative assets	65	57
Other Assets [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative assets	0	0
Other Assets [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative assets	65	57
Other Assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative assets	62	220
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset and liability netting	(43)	(11)
Total derivative liabilities, net	37	5
Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative liabilities	2	10
Other Liabilities [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative liabilities	0	0
Other Liabilities [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative liabilities	2	10
Other Liabilities [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivative liabilities	$ 78	$ 6