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Allowance for Credit Losses and Reserve for Unfunded Lending Commitments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Jan. 01, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss	$ 14,955		$ 14,955				$ 13,240
Financing Receivable Allowance For Credit Loss Translation Adjustments And Purchase Credit Deteriorated Loans	0	$ 10	32	$ 10
Allowance for credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (Decrease) in Allowance for Credit Loss			1,700
Allowance for credit loss	14,955	12,209	14,955	12,209	$ 14,646	$ 13,177	13,240	$ 11,491	$ 11,430
Credit Card: | Allowance for credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss	11,324	8,716	11,324	8,716	10,976	9,482	9,545	8,166	8,345
Consumer Banking: | Allowance for credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss	2,049	2,108	2,049	2,108	2,185	2,237	2,237	2,047	1,918
Commercial Portfolio | Allowance for credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss	$ 1,582	$ 1,385	$ 1,582	$ 1,385	$ 1,485	$ 1,458	$ 1,458	$ 1,278	$ 1,167

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- Definition

Financing Receivable Allowance For Credit Loss Translation Adjustments And Purchase Credit Deteriorated Loans

+ References

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Increase (Decrease) in Allowance for Credit Loss

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

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