Customer Deposits (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
U.S.:
Interest-bearing	$ 35,805	$ 37,271
Non-interest-bearing	8	4
Non-U.S.:
Interest-bearing	139	612
Non-interest-bearing	9	11
Total customer deposits	$ 35,961	$ 37,898