Non-U.S. Activities (Summary Of Non-U.S. Assets) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Interest-bearing deposits with banks	$ 38,636	$ 50,763
Other assets	23,357	18,016
Total assets	217,180	222,582
Non-U.S. Assets [Member]
Segment Reporting Information [Line Items]
Interest-bearing deposits with banks	5,221	20,665
Investment securities	30,586	28,976
Other assets	16,982	13,441
Total assets	$ 52,789	$ 63,082