Finance Receivables and Loans, Net (Troubled Debt Restructurings) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan	Dec. 31, 2023 USD ($)
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, gross carrying value	$ 2,400	$ 2,400
Loans modified, commitment to lend	$ 61	$ 18	$ 6
Number of loans | loan	52,662	78,162
Pre-modification amortized cost basis	$ 1,310	$ 1,458
Post-modification amortized cost basis	$ 1,289	$ 1,434
Consumer
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	52,657	78,158
Pre-modification amortized cost basis	$ 849	$ 1,419
Post-modification amortized cost basis	$ 823	$ 1,395
Consumer | Automotive
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	49,773	77,991
Pre-modification amortized cost basis	$ 831	$ 1,395
Post-modification amortized cost basis	$ 805	$ 1,371
Consumer | Consumer mortgage
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	31	54
Pre-modification amortized cost basis	$ 13	$ 24
Post-modification amortized cost basis	$ 13	$ 24
Consumer | Mortgage Finance
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	18	38
Pre-modification amortized cost basis	$ 12	$ 22
Post-modification amortized cost basis	$ 12	$ 22
Consumer | Mortgage — Legacy
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	13	16
Pre-modification amortized cost basis	$ 1	$ 2
Post-modification amortized cost basis	$ 1	$ 2
Consumer | Other
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	2,853	113
Pre-modification amortized cost basis	$ 5	$ 0
Post-modification amortized cost basis	$ 5	$ 0
Consumer | Credit card receivables
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	2,853	113
Pre-modification amortized cost basis	$ 5	$ 0
Post-modification amortized cost basis	$ 5	$ 0
Commercial
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	5	4
Pre-modification amortized cost basis	$ 461	$ 39
Post-modification amortized cost basis	$ 466	$ 39
Commercial | Automotive
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan		1
Pre-modification amortized cost basis		$ 2
Post-modification amortized cost basis		$ 2
Commercial | Other
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan	5	1
Pre-modification amortized cost basis	$ 461	$ 33
Post-modification amortized cost basis	$ 466	$ 33
Commercial | Commercial real estate
Financing Receivable, Troubled Debt Restructuring
Number of loans | loan		2
Pre-modification amortized cost basis		$ 4
Post-modification amortized cost basis		$ 4