Interest Income and Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income
Loans	$ 11,634	$ 9,995	$ 22,708	$ 19,746
Taxable securities	1,383	1,410	2,696	2,840
Non-taxable securities	395	479	805	937
Total investment securities	1,778	1,889	3,501	3,777
Trading assets	2,111	1,806	4,214	3,664
Federal funds sold and securities purchased under resale agreements	807	528	1,538	1,054
Securities borrowed	148	(21)	210	(65)
Deposits with banks	1,543	1,018	2,864	1,743
All other interest-earning assets	848	435	1,529	773
Total interest income	18,869	15,650	36,564	30,692
Interest expense
Interest-bearing deposits	1,340	629	2,400	1,112
Federal funds purchased and securities loaned or sold under repurchase agreements	759	387	1,337	680
Short-term borrowings	260	96	469	169
Trading liabilities – debt and all other interest-bearing liabilities	901	515	1,561	920
Long-term debt	2,003	1,687	3,756	3,276
Beneficial interest issued by consolidated VIEs	121	128	244	263
Total interest expense	5,384	3,442	9,767	6,420
Net interest income	13,485	12,208	26,797	24,272
Provision for credit losses	1,210	1,215	2,375	2,530
Net interest income after provision for credit losses	$ 12,275	$ 10,993	$ 24,422	$ 21,742