Interest Income and Interest Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income
Loans	$ 9,102	$ 9,507
Securities	2,295	2,216
Trading assets	2,394	2,885
Federal funds sold and securities purchased under resale agreements	651	543
Securities borrowed	37	47
Deposits with banks	152	101
Other assets	70	148
Total interest income	14,701	15,447
Interest expense
Interest-bearing deposits	722	922
Short-term and other liabilities	409	818
Long-term debt	1,722	1,588
Beneficial interests issued by consolidated VIEs	182	214
Total interest expense	3,035	3,542
Net interest income	11,666	11,905
Provision for credit losses	726	1,169
Net interest income after provision for credit losses	$ 10,940	$ 10,736