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Derivatives - Derivatives Associated With Cash Flow Hedges and Mortgage Banking Hedges (Details) - Hedging Instruments And Hedged Items - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022
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Cash Flow Hedge | Interest Rate Contract |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Variability in cash flows related to debt instruments (primarily loans) | $ 5,200 | $ 5,350
Cash Flow Hedge | Interest Rate Swap |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 5,200 | 5,350
Assets | 0 | 0
Liabilities | 118 | 71
Mortgage Banking Hedges | Option contracts written |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 84 | 35
Assets | 1 | 0
Liabilities | 0 | 0
Mortgage Banking Hedges | Forward contracts written |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 129 | 61
Assets | 1 | 0
Liabilities | $ 0 | $ 0

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