Interest Income and Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Interest income
Loans	$ 10,145	$ 10,889	$ 20,332	$ 23,194
Taxable securities	1,577	2,154	3,182	4,387
Non-taxable securities	270	307	547	607
Total investment securities	1,847	2,461	3,729	4,994
Trading assets - debt instruments	1,711	2,066	3,493	4,130
Federal funds sold and securities purchased under resale agreements	175	601	408	1,696
Securities borrowed	(90)	(175)	(167)	(23)
Deposits with banks	103	70	168	639
All other interest-earning assets	203	200	402	643
Total interest income	14,094	16,112	28,365	35,273
Interest expense
Interest-bearing deposits	132	349	278	1,924
Federal funds purchased and securities loaned or sold under repurchase agreements	60	131	75	918
Short-term borrowings	33	124	66	275
Trading liabilities – debt and all other interest-bearing liabilities	51	(43)	78	329
Long-term debt	1,056	1,639	2,190	3,386
Beneficial interest issued by consolidated VIEs	21	59	48	149
Total interest expense	1,353	2,259	2,735	6,981
Net interest income	12,741	13,853	25,630	28,292
Provision for credit losses	(2,285)	10,473	(6,441)	18,758
Net interest income after provision for credit losses	$ 15,026	$ 3,380	$ 32,071	$ 9,534