Fair Value Option - Summary of Fair Value and Unpaid Principal Balance (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, designated under fair value option	$ 0	$ 32
Commercial loans held for sale, Fair Value	48	36
Student Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, designated under fair value option	25	32
Loans held for investment, Unpaid Principal Balance	28	34
Fair Value Over (Under) Unpaid Principal Balance	(3)	(2)
Commercial loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Commercial loans held for sale, Fair Value	23	36
Commercial loans held for sale, Unpaid Principal Balance	23	36
Fair Value Over (Under) Unpaid Principal Balance	0	0
Fixed rate long-term debt
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value Over (Under) Unpaid Principal Balance	204	289
Fixed rate long-term debt, Fair Value	945	1,030
Fixed rate long-term debt, Unpaid Principal Balance	741	741
Fixed rate long-term debt \| Structured notes
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value Over (Under) Unpaid Principal Balance	1,163	1,363
Hybrid instruments, Unpaid Principal Balance	6,834	8,332
Hybrid instruments, structured notes, Fair Value	7,997	9,695
Structured deposits
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value Over (Under) Unpaid Principal Balance	284	311
Hybrid instruments, structured deposits, Fair Value	2,749	4,155
Hybrid instruments, Unpaid Principal Balance	$ 2,465	$ 3,844

Fair Value, Option, Loans Held As Assets

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- Definition

Fair Value Over (Under) Unpaid Principal Balance

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No definition available.

+ Details

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- Definition

Fixed-rate debt accounted for under fair value option.

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No definition available.

+ Details

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- Definition

Unpaid Principal Balance Commercial Syndicated Loans Held For Sale Carried At Fair Value

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No definition available.

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- Definition

Unpaid Principal Balance, Loans Receivable

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No definition available.

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- Definition

Unpaid principal balance on fixed-rate debt accounted for under FVO.

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No definition available.

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- Definition

Unpaid Principal Balance On Hybrid Instruments At Fair Value Option

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No definition available.

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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No definition available.

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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No definition available.

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