Derivatives - Derivatives Associated With Interest Rate Risk Management Activities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 3,724	$ 3,076
Assets	4	3
Liabilities	311	270
Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,958	3,076
Assets	222	91
Liabilities	6	6
Customer Interest Rate Contracts Hedging \| Hedging Instruments And Hedged Items \| Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	8,563	8,377
Assets	1	3
Liabilities	631	570
Customer Interest Rate Contracts Hedging \| Hedging Instruments And Hedged Items \| Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	8,563	8,377
Assets	626	351
Liabilities	$ 2	$ 5

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4E
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4E

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A

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Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

No definition available.

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

No definition available.

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