Customer Deposits (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Deposits By Type
Savings accounts - Direct	$ 15,795	$ 14,649
Certificates of deposit - Direct	965	893
Other deposits	682	627
Total customer deposits	38,219	37,898
United States [Member]
Deposits By Type
Certificates of deposit - Third party	9,684	10,781
Sweep accounts - Third party	$ 11,093	$ 10,948