Fair Value Measurement - Carrying Value and Estimated Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Financial assets
Cash and due from banks	$ 27,265	$ 29,066
Deposits with banks	503,554	595,085
Federal funds sold and securities purchased under resale agreements	392,763	276,152
Investment securities, held-to-maturity	294,803	342,754
Loans, net of allowance for loan losses	38,250	38,851
Financial liabilities
Beneficial interests issued by consolidated VIEs	27,104	23,020
Carrying value
Financial assets
Cash and due from banks	27,300	29,100
Deposits with banks	503,600	595,100
Accrued interest and accounts receivable	135,300	107,100
Federal funds sold and securities purchased under resale agreements	12,800	16,300
Securities borrowed	111,400	130,300
Investment securities, held-to-maturity	323,700	369,800
Loans, net of allowance for loan losses	1,259,500	1,262,500
Other	74,500	76,100
Financial liabilities
Deposits	2,327,100	2,322,300
Federal funds purchased and securities loaned or sold under repurchase agreements	64,500	47,500
Short-term borrowings	21,200	24,700
Accounts payable and other liabilities	253,500	241,800
Beneficial interests issued by consolidated VIEs	27,100	23,000
Long-term debt	300,500	303,900
Wholesale lending-related commitments	2,800	3,000
Carrying value | First Republic
Financial liabilities
Wholesale lending-related commitments	854	1,100
Total estimated fair value
Financial assets
Cash and due from banks	27,300	29,100
Deposits with banks	503,600	595,100
Accrued interest and accounts receivable	135,300	107,100
Federal funds sold and securities purchased under resale agreements	12,800	16,300
Securities borrowed	111,400	130,300
Investment securities, held-to-maturity	294,800	342,800
Loans, net of allowance for loan losses	1,245,100	1,250,200
Other	74,800	76,300
Financial liabilities
Deposits	2,327,700	2,322,600
Federal funds purchased and securities loaned or sold under repurchase agreements	64,500	47,500
Short-term borrowings	21,200	24,700
Accounts payable and other liabilities	252,300	241,400
Beneficial interests issued by consolidated VIEs	27,100	23,000
Long-term debt	300,200	303,500
Wholesale lending-related commitments	4,700	4,800
Total estimated fair value | Level 1
Financial assets
Cash and due from banks	27,300	29,100
Deposits with banks	503,400	594,600
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	127,200	160,600
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
Short-term borrowings	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 2
Financial assets
Cash and due from banks	0	0
Deposits with banks	200	500
Accrued interest and accounts receivable	135,200	107,000
Federal funds sold and securities purchased under resale agreements	12,800	16,300
Securities borrowed	111,400	130,300
Investment securities, held-to-maturity	167,600	182,200
Loans, net of allowance for loan losses	276,100	285,600
Other	73,100	74,900
Financial liabilities
Deposits	2,327,700	2,322,600
Federal funds purchased and securities loaned or sold under repurchase agreements	64,500	47,500
Short-term borrowings	21,200	24,700
Accounts payable and other liabilities	241,100	233,300
Beneficial interests issued by consolidated VIEs	27,100	23,000
Long-term debt	249,500	252,200
Wholesale lending-related commitments	0	0
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	969,000	964,600
Other	1,700	1,400
Financial liabilities
Deposits	0	0
Federal funds purchased and securities loaned or sold under repurchase agreements	0	0
Short-term borrowings	0	0
Accounts payable and other liabilities	11,200	8,100
Beneficial interests issued by consolidated VIEs	0	0
Long-term debt	50,700	51,300
Wholesale lending-related commitments	$ 4,700	$ 4,800