Allowance for Loan and Lease Losses - Schedule of Components of Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Receivables [Abstract]
Day 2 provision for loan and lease losses	$ 0	$ 0	$ 462	$ 454
Provision for loan and lease losses	212	50	452	33
Total provision for loan and lease losses	212	50	914	487
Day 2 provision for off-balance sheet credit exposure	0	0	254	59
(Benefit) provision for off-balance sheet credit exposure	(17)	10	(42)	20
Total (benefit) provision for off-balance sheet credit exposure	(17)	10	212	79
Benefit for investment securities available for sale credit losses	(3)	0	0	0
Provision for credit losses	$ 192	$ 60	$ 1,126	$ 566

Credit Loss Expense (Reversal)

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- Definition

Financing Receivable, Credit Loss, Expense

+ 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.

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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

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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

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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

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- References

No definition available.

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