Derivative Instruments and Other Financial Instruments Used For Hedging - Derivatives Designated as Cash Flow Hedges (Details) - Cash flow hedges - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amount and location of net gains and losses
Gains (Losses) Recognized in OCI (Effective Portion)	$ 51	$ (96)	$ (35)
Gains (Losses) Reclassified from AOCI into Income (Effective Portion)	(91)	(34)	69
Noninterest expense
Amount and location of net gains and losses
Gains (Losses) Recognized in Income (Ineffective Portion)		(1)	3
Designated as hedging instrument \| Interest rate contracts
Amount and location of net gains and losses
Gains (Losses) Recognized in OCI (Effective Portion)	51	(96)	(35)
Designated as hedging instrument \| Interest rate contracts \| Interest income
Amount and location of net gains and losses
Gains (Losses) Reclassified from AOCI into Income (Effective Portion)	(91)	(34)	69
Designated as hedging instrument \| Interest rate contracts \| Interest expense
Amount and location of net gains and losses
Gains (Losses) Reclassified from AOCI into Income (Effective Portion)	$ 0	0	0
Designated as hedging instrument \| Interest rate contracts \| Noninterest expense
Amount and location of net gains and losses
Gains (Losses) Recognized in Income (Ineffective Portion)		$ (1)	$ 3

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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- Definition

The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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