Finance Receivable Sale Agreements - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) agreementType	Jun. 30, 2021 USD ($)	Mar. 22, 2022 USD ($)	Mar. 31, 2021 USD ($)
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Number of agreement types | agreementType			2
Consumer Loan | MPSA
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Commitment of purchaser, current availability financing, principal balances of finance receivables	$ 5,000,000,000		$ 5,000,000,000		$ 5,000,000,000	$ 4,000,000,000
Commitment of purchaser, current availability financing, principal balances of finance receivables, amount increased from previous commitment					$ 1,000,000,000
Principal balances of finance receivables sold	1,300,000,000	$ 597,000,000	1,800,000,000	$ 1,100,000,000
Receivable purchase agreement, remaining unused capacity	3,200,000,000		3,200,000,000
Consumer Loan | Master Purchase Sale Agreement, 2017 Master Transfer Agreement and Other Partners
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Gain on loan sales	130,000,000	200,000,000	235,000,000	338,000,000
Securitization Transaction
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Principal balances of finance receivables sold	$ 605,000,000	$ 1,200,000,000	$ 2,000,000,000	$ 2,000,000,000