Fair Value (Fair Value Measurements - Nonrecurring Basis) (Details) - USD ($) $ in Millions		12 Months Ended
	Apr. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		$ 549	$ 406
Finance receivables and loans, net		119,001	115,251
Goodwill impairment		0	50	$ 0
Corporate and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill impairment	$ 50		50
Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		595	530
Lower of cost or fair value, valuation reserve, or cumulative adjustments		(70)	62
Mortgage loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		468	315
Lower of cost or fair value, 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		7	125
Lower of cost or fair value, valuation reserve, or cumulative adjustments		(5)	88
Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets		4	9
Lower of cost or fair value, valuation reserve, or cumulative adjustments		0	(1)
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 | Mortgage loans held-for-sale | 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	7
Fair value, inputs, level 2 | Mortgage loans held-for-sale | 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	7
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		595	523
Fair value, inputs, level 3 | Mortgage loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		468	315
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		7	118
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		4	9
Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net		116	81
Lower of cost or fair value, valuation reserve, or cumulative adjustments		(65)	(25)
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		116	81
Automotive loan | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net		4	27
Lower of cost or fair value, valuation reserve, or cumulative adjustments		0	(5)
Automotive loan | 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 loan | 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 loan | 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		4	27
Other | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net		112	54
Lower of cost or fair value, valuation reserve, or cumulative adjustments		(65)	(20)
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		$ 112	$ 54