Interest Income and Interest Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest income
Loans	$ 35,832	$ 37,098	$ 40,388
Securities	7,939	9,215	9,540
Trading assets	9,039	11,142	11,007
Federal funds sold and securities purchased under resale agreements	2,442	2,523	1,786
Securities borrowed	(3)	110	175
Deposits with banks	555	599	345
Other assets	259	606	541
Total interest income	56,063	61,293	63,782
Interest expense
Interest-bearing deposits	2,655	3,855	3,424
Short-term and other liabilities	1,788	2,873	2,364
Long-term debt	6,062	6,109	5,848
Beneficial interests issued by consolidated VIEs	648	767	1,145
Total interest expense	11,153	13,604	12,781
Net interest income	44,910	47,689	51,001
Provision for credit losses	3,385	7,574	16,639
Net interest income after provision for credit losses	$ 41,525	$ 40,115	$ 34,362