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Finance Receivables and Loans, Net - Schedule of Financing Receivables, Nonaccrual Status (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 1,226		$ 1,226		$ 1,306	$ 1,366	$ 1,417	$ 1,486
Financing receivable, nonaccrual, with no allowance	442		442			485
Financing receivable, nonaccrual, interest income	14	$ 3	27	$ 7
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,176		1,176		1,190	1,217	1,223	1,375
Financing receivable, nonaccrual, with no allowance	439		439			460
Consumer \| Consumer automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,122		1,122		1,128	1,155	1,167	1,231
Financing receivable, nonaccrual, with no allowance	405		405			416
Consumer \| Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	54		54		62	62	56	54
Financing receivable, nonaccrual, with no allowance	34		34			44
Consumer \| Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status						0	0	90
Financing receivable, nonaccrual, with no allowance						0
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	50		50		116	149	194	111
Financing receivable, nonaccrual, with no allowance	3		3			25
Commercial \| Consumer automotive
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1		1		3	15	79	15
Financing receivable, nonaccrual, with no allowance	1		1			15
Commercial \| Consumer mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	2		2		1	10	21	2
Financing receivable, nonaccrual, with no allowance	2		2			10
Commercial \| Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	47		47		$ 112	124	$ 94	$ 94
Financing receivable, nonaccrual, with no allowance	$ 0		$ 0			$ 0