Securitizations and Financings - Securitization Trusts (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entities and Securitizations [Abstract]
Total collateral balances - UPB	$ 1,074	$ 1,122
Total certificate balances	1,061	1,112
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Unconsolidated securitization trusts	$ 134	$ 138

Amount, before allowance for credit loss, of financing receivable.

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