Variable Interest Entities and Securitizations - Continuing Involvement in Securitization Related VIEs (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
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Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Securities held by third-party investors, non-mortgage	$ 12,808	$ 10,361
Receivables in the trust, non-mortgage	22,454	23,683
Cash balance of spread or reserve accounts, non-mortgage	0	0
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Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Securities held by third-party investors, non-mortgage	2,186	2,053
Receivables in the trust, non-mortgage	2,418	2,243
Cash balance of spread or reserve accounts, non-mortgage	$ 13	$ 10