Interest Income and Interest Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Interest income
Loans	$ 8,341	$ 8,902	$ 16,854	$ 18,004
Securities	1,778	2,101	3,668	4,396
Trading assets	2,197	2,265	4,470	4,659
Federal funds sold and securities purchased under resale agreements	490	646	1,004	1,297
Securities borrowed	(30)	(12)	(36)	25
Deposits with banks	222	136	385	288
Other assets	147	61	227	131
Total interest income	13,145	14,099	26,572	28,800
Interest expense
Interest-bearing deposits	539	737	1,084	1,459
Short-term and other liabilities	515	513	1,035	922
Long-term debt	1,261	1,538	2,556	3,260
Beneficial interests issued by consolidated VIEs	126	165	260	347
Interest expense	2,441	2,953	4,935	5,988
Net interest income	10,704	11,146	21,637	22,812
Provision for credit losses	47	214	664	940
Net interest income after provision for credit losses	$ 10,657	$ 10,932	$ 20,973	$ 21,872