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Derivatives - Derivatives Associated With Interest Rate Risk Management Activities (Details) - USD ($) $ in Millions | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Customer interest rate contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | $ 3,815 | $ 3,950
Assets | 124 | 207
Liabilities | 33 | 7
Offsetting upstream interest rate contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 3,815 | 3,950
Assets | 6 | 2
Liabilities | 10 | 17
Customer Interest Rate Contracts Hedging | Hedging Instruments And Hedged Items | Customer interest rate contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 7,231 | 6,868
Assets | 286 | 436
Liabilities | 14 | 1
Customer Interest Rate Contracts Hedging | Hedging Instruments And Hedged Items | Offsetting upstream interest rate contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 7,231 | 6,868
Assets | 3 | 5
Liabilities | $ 15 | $ 35

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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
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