Interest Income and Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income
Loans	$ 12,207	$ 10,519	$ 34,915	$ 30,265
Taxable securities	1,402	1,362	4,098	4,202
Non-taxable securities	394	456	1,199	1,393
Total investment securities	1,796	1,818	5,297	5,595
Trading assets	2,155	1,947	6,369	5,611
Federal funds sold and securities purchased under resale agreements	952	622	2,490	1,676
Securities borrowed	200	0	410	(65)
Deposits with banks	1,585	1,259	4,449	3,002
All other interest-earning assets	945	522	2,474	1,295
Total interest income	19,840	16,687	56,404	47,379
Interest expense
Interest-bearing deposits	1,621	837	4,021	1,949
Federal funds purchased and securities loaned or sold under repurchase agreements	827	451	2,164	1,131
Short-term borrowings	288	149	757	318
Trading liabilities – debt and all other interest-bearing liabilities	1,018	570	2,579	1,490
Long-term debt	2,056	1,759	5,812	5,035
Beneficial interest issued by consolidated VIEs	122	123	366	386
Total interest expense	5,932	3,889	15,699	10,309
Net interest income	13,908	12,798	40,705	37,070
Provision for credit losses	948	1,452	3,323	3,982
Net interest income after provision for credit losses	$ 12,960	$ 11,346	$ 37,382	$ 33,088