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Derivatives - Derivatives Associated With Cash Flow Hedges (Details) - Hedging Instruments And Hedged Items - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flow Hedges | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Variability in cash flows related to debt instruments (primarily loans)	$ 1,500	$ 900
Cash Flow Hedges | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,500	900
Assets	32
Liabilities	0	$ 0
Mortgage Banking Hedges | Interest Rate Lock
Derivative Instruments, Gain (Loss) [Line Items]
Notional	667
Assets	20
Liabilities	0
Gain (loss) on derivative instruments	15
Mortgage Banking Hedges | Forward Sales Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	725
Assets	0
Liabilities	6
Gain (loss) on derivative instruments	$ (37)

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- Definition

Held-to-maturity trust preferred loans.

+ References

No definition available.

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- Definition

Fair value of all asset derivatives designated as cash flow hedging instruments.

+ References

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-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 4B
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- Definition

Fair value of all liability derivatives designated as cash flow hedging instruments.

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- Definition

Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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- Definition

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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