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Allowance for Loan and Lease Losses - Schedule of Components of Credit Losses (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Receivables [Abstract] |  |  |
Day 2 provision for loan and lease losses | $ 462 | $ 454 | $ 0
Provision for credit losses - loans and leases | 703 | 97 |
(Benefit) for credit losses - loans and leases |  |  | (37)
Total provision for loan and lease losses | 1,165 | 551 | (37)
Day 2 provision for off-balance sheet credit exposure | 254 | 59 | 0
(Benefit) provision for off-balance sheet credit exposure | (44) | 35 | 0
Total provision for off-balance sheet credit exposure | 210 | 94 | 0
Benefit for investment securities available for sale credit losses | 0 |  | 0
Provision (benefit) for credit losses | $ 1,375 | $ 645 | $ (37)

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- Definition Financing Receivable, Credit Loss, Expense + References No definition available. + Details
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- Definition Financing Receivable, Credit Loss, Reversal + References No definition available. + Details
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- Definition Financing Receivable, Excluding Accrued Interest, Purchased without Credit Deterioration, Allowance for Credit Loss at Acquisition Date + References No definition available. + Details
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- Definition Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal), Acquired In Acquisition + References No definition available. + Details
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- Definition Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal), Excluding Amount Acquired In Acquisition + References No definition available. + Details
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- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with previously recorded allowance and not intended to be sold and not more likely than not will be required to sell before recovery of amortized cost basis. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479106/326-30-50-9 + Details
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- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
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- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
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