Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Weighted-average discount rates for fair value estimations	46.00%
Historical recovery rate of collateral values of consumer installment loans	49.00%
Residential Mortgage Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Capitalized servicing rights	$ 456,000,000	$ 194,000,000	$ 241,000,000	$ 231,000,000
Capitalized servicing rights, valuation allowance			(24,000,000)
Weighted-average prepayment speeds	6.93%
Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rates for fair value estimations	10.00%
Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rates for fair value estimations	90.00%
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value of nonrecurring fair value measured loans for charge-offs and impairment reserves	$ (381,000,000)	(191,000,000)	(53,000,000)
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Capitalized servicing rights, valuation allowance	0	0
Valuation Charge Recognized		24,000,000	6,000,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	923,000,000	853,000,000	574,000,000
Fair Value, Measurements, Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	234,000,000	329,000,000	340,000,000
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	$ 689,000,000	$ 524,000,000	$ 234,000,000