Fair Values - Financial Instruments Not Measured at Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financial assets
Securities borrowed	$ 138,508	$ 129,713
Customer and other receivables	82,759	96,018
Loans	193,453	174,302
Financial liabilities
Deposits	347,148	347,574
Securities sold under agreements to repurchase	66,179	62,188
Securities loaned	13,785	12,299
Other secured financings	7,237	10,041
Customer and other payables	234,007	228,685
Borrowings	226,177	233,127
Carrying Value
Financial assets
Cash and cash equivalents	131,286	127,725
Investment securities—HTM	79,477	80,168
Securities purchased under agreements to resell	120,735	119,992
Securities borrowed	138,508	129,713
Customer and other receivables	78,752	91,664
Loans	206,482	188,134
Other assets	722	528
Financial liabilities
Deposits	344,192	345,634
Securities sold under agreements to repurchase	65,223	61,397
Securities loaned	13,785	12,299
Other secured financings	3,107	4,908
Customer and other payables	233,719	228,631
Borrowings	155,505	156,787
Additional Disclosures
Lending commitments	139,858	133,519
Fair Value
Financial assets
Cash and cash equivalents	131,286	127,725
Investment securities—HTM	71,742	79,882
Securities purchased under agreements to resell	120,658	119,997
Securities borrowed	138,506	129,713
Customer and other receivables	78,491	91,533
Loans	201,673	189,490
Other assets	722	528
Financial liabilities
Deposits	344,259	345,911
Securities sold under agreements to repurchase	65,163	61,419
Securities loaned	13,791	12,296
Other secured financings	3,108	4,910
Customer and other payables	233,719	228,631
Borrowings	152,741	162,158
Additional Disclosures
Lending commitments	2,891	1,360
Fair Value | Level 1
Financial assets
Cash and cash equivalents	131,286	127,725
Investment securities—HTM	29,093	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	41,619	49,352
Securities purchased under agreements to resell	118,453	117,922
Securities borrowed	138,506	129,713
Customer and other receivables	74,975	88,091
Loans	26,339	25,706
Other assets	722	528
Financial liabilities
Deposits	344,259	345,911
Securities sold under agreements to repurchase	65,163	61,419
Securities loaned	13,791	12,296
Other secured financings	3,108	4,910
Customer and other payables	233,719	228,631
Borrowings	152,737	162,154
Additional Disclosures
Lending commitments	2,086	890
Fair Value | Level 3
Financial assets
Cash and cash equivalents	0	0
Investment securities—HTM	1,030	1,076
Securities purchased under agreements to resell	2,205	2,075
Securities borrowed	0	0
Customer and other receivables	3,516	3,442
Loans	175,334	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	$ 805	$ 470