Non-U.S. Activities - Summary Of Non-U.S. Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Interest-bearing deposits with banks	$ 83,398	$ 93,523
Other assets	37,549	32,600
Total assets	279,476	274,119
Non- U.S.
Segment Reporting Information [Line Items]
Interest-bearing deposits with banks	26,893	17,382
Investment securities	26,863	29,060
Other assets	13,948	13,577
Total assets	$ 67,704	$ 60,019