Variable Interest Entities (Details Textual) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Variable Interest Entities (Textual) [Abstract]
Balance related to consolidated VIEs of other liabilities	$ 187	$ 88
Variable Interest Entity [Line Items]
Maximum exposure to loss	3,211		2,470
Variable Interest Entities (Additional Textual) [Abstract]
Trading assets arising due to "failed sale" accounting treatment	62	73
Long-term liabilities arising due to "failed sale" accounting treatment	73	89
Asset Backed Commercial Paper Conduits [Member]
Variable Interest Entity [Line Items]
Maximum exposure to loss	1,142	677
Credit card operations [Member]
Variable Interest Entities (Textual) [Abstract]
Remaining balances related to consolidated VIEs as part of other assets	44
Balance related to consolidated VIEs of other liabilities	$ 273	$ 541