Interest Income and Interest Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest income
Loans	$ 32,218	$ 33,489	$ 35,832
Taxable securities	7,617	6,916	7,231
Non-taxable securities(a)	1,423	896	708
Total securities	9,040	7,812	7,939
Trading assets	7,312	8,099	8,929
Federal funds sold and securities purchased under resale agreements	1,642	1,940	2,442
Securities borrowed	(501)	(127)	(3)
Deposits with banks	1,157	918	555
Other assets	663	538	259
Total interest income	51,531	52,669	55,953
Interest expense
Interest-bearing deposits	1,633	2,067	2,655
Short-term and other liabilities	1,450	1,798	1,678
Long-term debt	4,409	5,007	6,062
Beneficial interests issued by consolidated VIEs	405	478	648
Total interest expense	7,897	9,350	11,043
Net interest income	43,634	43,319	44,910
Provision for credit losses	3,139	225	3,385
Net interest income after provision for credit losses	$ 40,495	$ 43,094	$ 41,525