Interest Income and Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income
Loans	$ 10,187	$ 12,305
Taxable securities	1,605	2,233
Non-taxable securities	277	300
Total investment securities	1,882	2,533
Trading assets - debt instruments	1,782	2,064
Federal funds sold and securities purchased under resale agreements	233	1,095
Securities borrowed	(77)	152
Deposits with banks	65	569
All other interest-earning assets	199	443
Total interest income	14,271	19,161
Interest expense
Interest-bearing deposits	146	1,575
Federal funds purchased and securities loaned or sold under repurchase agreements	15	787
Short-term borrowings	33	151
Trading liabilities – debt and all other interest-bearing liabilities	27	372
Long-term debt	1,134	1,747
Beneficial interest issued by consolidated VIEs	27	90
Total interest expense	1,382	4,722
Net interest income	12,889	14,439
Provision for credit losses	(4,156)	8,285
Net interest income after provision for credit losses	$ 17,045	$ 6,154