Derivative Instruments and Hedging Activities (Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged liability, fair value hedge	$ 7,736	$ 7,697
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt	Long-term debt
Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged asset, fair value hedge	$ 14,478	$ 11,265
Hedged asset, fair value hedge, cumulative increase (decrease)	(434)	(180)
Closed portfolio and beneficial interest, last-of-layer, amortized cost	13,000	10,000
Amortized cost	12,800	9,700
Basis adjustment for active hedge	(360)	(135)
Hedged asset, last-of-layer, amount	10,500	4,000
Available-for-sale securities | Total derivatives designated as accounting hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Basis adjustment for active hedge	(234)	3
Finance receivables and loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged asset, fair value hedge	46,091	46,390
Hedged asset, fair value hedge, cumulative increase (decrease)	(358)	(617)
Basis adjustment for active hedge	(358)	(617)
Hedged asset, last-of-layer, amount	21,300	22,800
Closed portfolio, carrying value	40,100	46,100
Finance receivables and loans, net | Total derivatives designated as accounting hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Basis adjustment for active hedge	(328)	(560)
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged liability, fair value hedge, cumulative increase (decrease)	102	112
Discontinued hedge | Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged asset, discontinued fair value hedge, cumulative increase (decrease)	(164)	(181)
Basis adjustment for active hedge	(126)	(138)
Discontinued hedge | Finance receivables and loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged asset, discontinued fair value hedge, cumulative increase (decrease)	(30)	(57)
Basis adjustment for active hedge	(30)	(57)
Discontinued hedge | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged liability, discontinued fair value hedge, cumulative increase (decrease)	$ 102	$ 120