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Fair Value of Assets and Liabilities - Changes In Fair Value Of Assets And Liabilities Which Fair Value Option Included In Current Period Earnings (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Mortgage Banking Noninterest Income | Loans held for sale |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Changes in fair value included in net income | $ 4 | $ 0 | $ (5) | $ 1

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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. + References No definition available. + Details
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- Definition For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14172-108612 + Details
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