Derivative Instruments and Hedging Activities (Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	$ 1,217	$ 1,485
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	18	0
Closed Portfolio and Beneficial Interest, Last-of-Layer, Amortized Cost	230	47
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount		28
Hedge basis adjustment, last-of-layer		0
Hedged asset, last-of-layer, amount	0
Finance receivables and Loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	33,312	40,850
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	135	24
Hedge basis adjustment, last-of-layer	91	19
Hedged asset, last-of-layer, amount	10,200	21,400
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	11,995	13,001
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	24	67
Discontinued hedge | Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	18	(5)
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount	200
Hedge basis adjustment, last-of-layer	2
Discontinued hedge | Finance receivables and Loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	44	5
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount	12,800
Hedge basis adjustment, last-of-layer	43
Discontinued hedge | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	$ 127	$ 67