Fair Values - Financial Instruments Not Measured at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financial assets
Securities borrowed	$ 136,478	$ 129,713
Customer and other receivables	87,935	96,018
Loans	197,583	174,302
Financial liabilities
Deposits	338,123	347,574
Securities sold under agreements to repurchase	60,133	62,188
Securities loaned	13,097	12,299
Other secured financings	7,701	10,041
Customer and other payables	229,463	228,685
Borrowings	220,423	233,127
Carrying Value
Financial assets
Cash and cash equivalents	111,696	127,725
Investment securities—HTM	77,636	80,168
Securities purchased under agreements to resell	111,124	119,992
Securities borrowed	136,478	129,713
Customer and other receivables	83,417	91,664
Loans	210,936	188,134
Other assets	704	528
Financial liabilities
Deposits	334,462	345,634
Securities sold under agreements to repurchase	59,182	61,397
Securities loaned	13,097	12,299
Other secured financings	3,107	4,908
Customer and other payables	229,272	228,631
Borrowings	151,635	156,787
Additional Disclosures
Lending commitments	135,899	133,519
Fair Value
Financial assets
Cash and cash equivalents	111,696	127,725
Investment securities—HTM	66,393	79,882
Securities purchased under agreements to resell	110,992	119,997
Securities borrowed	136,471	129,713
Customer and other receivables	83,051	91,533
Loans	203,671	189,490
Other assets	704	528
Financial liabilities
Deposits	334,378	345,911
Securities sold under agreements to repurchase	59,070	61,419
Securities loaned	13,096	12,296
Other secured financings	3,107	4,910
Customer and other payables	229,272	228,631
Borrowings	148,109	162,158
Additional Disclosures
Lending commitments	2,945	1,360
Fair Value | Level 1
Financial assets
Cash and cash equivalents	111,696	127,725
Investment securities—HTM	27,657	29,454
Securities purchased under agreements to resell	0	0
Securities borrowed	0	0
Customer and other receivables	0	0
Loans	0	0
Other assets	0	0
Financial liabilities
Deposits	0	0
Securities sold under agreements to repurchase	0	0
Securities loaned	0	0
Other secured financings	0	0
Customer and other payables	0	0
Borrowings	0	0
Additional Disclosures
Lending commitments	0	0
Fair Value | Level 2
Financial assets
Cash and cash equivalents	0	0
Investment securities—HTM	37,721	49,352
Securities purchased under agreements to resell	108,312	117,922
Securities borrowed	136,471	129,713
Customer and other receivables	79,493	88,091
Loans	25,100	25,706
Other assets	704	528
Financial liabilities
Deposits	334,378	345,911
Securities sold under agreements to repurchase	59,070	61,419
Securities loaned	13,096	12,296
Other secured financings	3,107	4,910
Customer and other payables	229,272	228,631
Borrowings	148,105	162,154
Additional Disclosures
Lending commitments	2,065	890
Fair Value | Level 3
Financial assets
Cash and cash equivalents	0	0
Investment securities—HTM	1,015	1,076
Securities purchased under agreements to resell	2,680	2,075
Securities borrowed	0	0
Customer and other receivables	3,558	3,442
Loans	178,571	163,784
Other assets	0	0
Financial liabilities
Deposits	0	0
Securities sold under agreements to repurchase	0	0
Securities loaned	0	0
Other secured financings	0	0
Customer and other payables	0	0
Borrowings	4	4
Additional Disclosures
Lending commitments	$ 880	$ 470