Fair Value (Fair Value Measurements - Nonrecurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	$ 654	$ 549
Finance receivables and loans, net	132,037	119,001
Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	700	595
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	(86)	(70)
Loans held-for-sale, net | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	641	468
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	0	0
Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	12	7
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	3	(5)
Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	5	4
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	0	0
Fair value, inputs, level 1 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Fair value, inputs, level 1 | Loans held-for-sale, net | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	0	0
Fair value, inputs, level 1 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair value, inputs, level 1 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair value, inputs, level 2 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Fair value, inputs, level 2 | Loans held-for-sale, net | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	0	0
Fair value, inputs, level 2 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair value, inputs, level 2 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair value, inputs, level 3 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	700	595
Fair value, inputs, level 3 | Loans held-for-sale, net | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	641	468
Fair value, inputs, level 3 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	12	7
Fair value, inputs, level 3 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	5	4
Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	42	116
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	(89)	(65)
Commercial | Fair value, inputs, level 1 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Commercial | Fair value, inputs, level 2 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Commercial | Fair value, inputs, level 3 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	42	116
Automotive | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	3	4
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	0	0
Automotive | Commercial | Fair value, inputs, level 1 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Automotive | Commercial | Fair value, inputs, level 2 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Automotive | Commercial | Fair value, inputs, level 3 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	3	4
Other | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	39	112
Lower-of-cost-or-fair-value reserve, valuation reserve, or cumulative adjustments	(89)	(65)
Other | Commercial | Fair value, inputs, level 1 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Other | Commercial | Fair value, inputs, level 2 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0	0
Other | Commercial | Fair value, inputs, level 3 | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	$ 39	$ 112