Loans and Allowance for Credit Losses - Narrative (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) loan_segment loan	Mar. 31, 2020 USD ($) loan	Dec. 31, 2020 USD ($) loan
Financing Receivable, Credit Quality Indicator [Line Items]
Number of loans and leases segments \| loan_segment	2
Loans and leases pledged as collateral	$ 8,630		$ 8,070
Number of loans on non-accrual status \| loan	0		0
Sale of loans	$ 35	$ 93
Loss on sale of loans	$ (7)
Loans modified in troubled debt restructurings \| loan	0	0
Loans no longer meeting similar risk of collective pool \| loan	9
Loans no longer meeting similar risk of collective pool, amount	$ 212
Allowance for credit loss	$ 118		$ 122
Investment grade loans	82.00%
Speculative grade loans	17.00%
Speculative senior secured loans with BB or B rating	86.00%
Allowance for credit loss, period increase (decrease)	$ 13	$ 31
Provision for credit losses	(9)	$ 36
Leveraged Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Sale of loans	42
Commercial and Financial Segment
Financing Receivable, Credit Quality Indicator [Line Items]
Allowance for credit loss	$ 20

Financing Receivable, Recorded Investment, Nonaccrual Status, Number of Loans

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- Definition

Investment Grade Loans

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Loans And Leases Receivable, Number Of Loans And Leases Segments

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Loans No Longer Meeting Similar Risk of Collective Pool

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- Definition

Number of Loans, No Longer Met Similar Risk

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- Definition

Speculative Grade Loans

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No definition available.

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- Definition

Speculative Senior Secured Loans, with BB or B Rating

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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

+ References

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- Definition

Amount of increase (decrease) in allowance for credit loss on financing receivable.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

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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

Amount of gain (loss) on sale of financing receivable.

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- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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- Definition

The cash inflow associated with the sale of loans receivables arising from the financing of goods and services.

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- Definition

Amount of credit loss expense (reversal of expense) for financing receivable.

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