Fair Value Measurement - Carrying Value and Estimated Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financial assets
Cash and due from banks	$ 26,165	$ 26,438
Deposits with banks	728,367	714,396
Federal funds sold and securities purchased under resale agreements	301,875	261,698
Investment securities, held-to-maturity	350,494	362,628
Loans, net of allowance for loan losses	48,463	58,820
Financial liabilities
Beneficial interests issued by consolidated VIEs	10,144	10,750
Carrying value
Financial assets
Cash and due from banks	26,200	26,400
Deposits with banks	728,400	714,400
Accrued interest and accounts receivable	151,400	102,100
Federal funds sold and securities purchased under resale agreements	3,500	9,000
Securities borrowed	137,600	124,600
Investment securities, held-to-maturity	366,600	363,700
Loans, net of allowance for loan losses	1,007,600	1,002,500
Other	104,200	98,700
Financial liabilities
Deposits	2,550,800	2,451,000
Federal funds purchased and securities loaned or sold under repurchase agreements	77,700	67,900
Accounts payable and other liabilities	283,600	217,600
Beneficial interests issued by consolidated VIEs	10,100	10,700
Long-term debt	222,500	226,000
Wholesale lending-related commitments	2,300	2,100
Carrying value | Short-term borrowings
Financial liabilities
Commercial paper and Short-term borrowings	38,400	33,600
Total estimated fair value
Financial assets
Cash and due from banks	26,200	26,400
Deposits with banks	728,400	714,400
Accrued interest and accounts receivable	151,400	102,100
Federal funds sold and securities purchased under resale agreements	3,500	9,000
Securities borrowed	137,600	124,600
Investment securities, held-to-maturity	350,500	362,600
Loans, net of allowance for loan losses	1,013,300	1,023,200
Other	104,300	98,800
Financial liabilities
Deposits	2,550,800	2,451,000
Federal funds purchased and securities loaned or sold under repurchase agreements	77,700	67,900
Accounts payable and other liabilities	283,000	217,000
Beneficial interests issued by consolidated VIEs	10,100	10,800
Long-term debt	224,800	232,600
Wholesale lending-related commitments	2,900	2,900
Total estimated fair value | Short-term borrowings
Financial liabilities
Commercial paper and Short-term borrowings	38,400	33,600
Total estimated fair value | Level 1
Financial assets
Cash and due from banks	26,200	26,400
Deposits with banks	728,400	714,400
Accrued interest and accounts receivable	0	0
Federal funds sold and securities purchased under resale agreements	0	0
Securities borrowed	0	0
Investment securities, held-to-maturity	177,500	183,300
Loans, net of allowance for loan losses	0	0
Other	0	0
Financial liabilities
Deposits	0	0
Federal funds purchased and securities loaned or sold under repurchase agreements	0	0
Accounts payable and other liabilities	0	0
Beneficial interests issued by consolidated VIEs	0	0
Long-term debt	0	0
Wholesale lending-related commitments	0	0
Total estimated fair value | Level 1 | Short-term borrowings
Financial liabilities
Commercial paper and Short-term borrowings	0	0
Total estimated fair value | Level 2
Financial assets
Cash and due from banks	0	0
Deposits with banks	0	0
Accrued interest and accounts receivable	151,300	102,000
Federal funds sold and securities purchased under resale agreements	3,500	9,000
Securities borrowed	137,600	124,600
Investment securities, held-to-maturity	173,000	179,300
Loans, net of allowance for loan losses	198,900	202,100
Other	102,000	97,400
Financial liabilities
Deposits	2,550,800	2,451,000
Federal funds purchased and securities loaned or sold under repurchase agreements	77,700	67,900
Accounts payable and other liabilities	278,000	212,100
Beneficial interests issued by consolidated VIEs	10,100	10,800
Long-term debt	221,700	229,500
Wholesale lending-related commitments	0	0
Total estimated fair value | Level 2 | Short-term borrowings
Financial liabilities
Commercial paper and Short-term borrowings	38,400	33,600
Total estimated fair value | Level 3
Financial assets
Cash and due from banks	0	0
Deposits with banks	0	0
Accrued interest and accounts receivable	100	100
Federal funds sold and securities purchased under resale agreements	0	0
Securities borrowed	0	0
Investment securities, held-to-maturity	0	0
Loans, net of allowance for loan losses	814,400	821,100
Other	2,300	1,400
Financial liabilities
Deposits	0	0
Federal funds purchased and securities loaned or sold under repurchase agreements	0	0
Accounts payable and other liabilities	5,000	4,900
Beneficial interests issued by consolidated VIEs	0	0
Long-term debt	3,100	3,100
Wholesale lending-related commitments	2,900	2,900
Total estimated fair value | Level 3 | Short-term borrowings
Financial liabilities
Commercial paper and Short-term borrowings	$ 0	$ 0