Customer Deposits (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
U.S.:
Interest-bearing	$ 37,537	$ 37,271
Non-interest-bearing	4	4
Non-U.S.:
Interest-bearing	667	612
Non-interest-bearing	11	11
Total customer deposits	$ 38,219	$ 37,898