Investment Securities (Gross Unrealized Loss and Fair Value of Securities Available for Sale) (Details) (USD $) In Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Debt Securities [Member]
Unrealized loss position less than 12 months - unrealized loss	$ (148)	$ (500)
Unrealized loss position less than 12 months - fair value	10,013	20,384
Unrealized loss position 12 months or more - unrealized loss	(1,235)	(1,476)
Unrealized loss position 12 months or more - fair value	6,636	7,013
Total unrealized loss	(1,383)	(1,976)
Total fair value	16,649	27,397
US Treasury and Government Agencies Securities [Member]
Unrealized loss position less than 12 months - unrealized loss	(12)	(22)
Unrealized loss position less than 12 months - fair value	232	398
Total unrealized loss	(12)	(22)
Total fair value	232	398
Residential Mortgage-backed Agency [Member]
Unrealized loss position less than 12 months - unrealized loss	(76)	(406)
Unrealized loss position less than 12 months - fair value	6,465	17,040
Unrealized loss position 12 months or more - unrealized loss	(29)	(14)
Unrealized loss position 12 months or more - fair value	841	186
Total unrealized loss	(105)	(420)
Total fair value	7,306	17,226
Residential Mortgage-backed Non-agency [Member]
Unrealized loss position less than 12 months - unrealized loss	(26)	(17)
Unrealized loss position less than 12 months - fair value	601	345
Unrealized loss position 12 months or more - unrealized loss	(972)	(1,173)
Unrealized loss position 12 months or more - fair value	4,810	5,707
Total unrealized loss	(998)	(1,190)
Total fair value	5,411	6,052
Commercial Mortgage-backed Agency [Member]
Unrealized loss position less than 12 months - unrealized loss	(1)	(6)
Unrealized loss position less than 12 months - fair value	1	344
Total unrealized loss	(1)	(6)
Total fair value	1	344
Commercial Mortgage-backed Non-agency [Member]
Unrealized loss position less than 12 months - unrealized loss	(12)	(8)
Unrealized loss position less than 12 months - fair value	1,178	184
Unrealized loss position 12 months or more - unrealized loss		(3)
Unrealized loss position 12 months or more - fair value		84
Total unrealized loss	(12)	(11)
Total fair value	1,178	268
Asset backed [Member]
Unrealized loss position less than 12 months - unrealized loss	(6)	(5)
Unrealized loss position less than 12 months - fair value	819	441
Unrealized loss position 12 months or more - unrealized loss	(185)	(233)
Unrealized loss position 12 months or more - fair value	722	776
Total unrealized loss	(191)	(238)
Total fair value	1,541	1,217
State and Municipal [Member]
Unrealized loss position less than 12 months - unrealized loss	(5)	(22)
Unrealized loss position less than 12 months - fair value	363	931
Unrealized loss position 12 months or more - unrealized loss	(47)	(50)
Unrealized loss position 12 months or more - fair value	250	247
Total unrealized loss	(52)	(72)
Total fair value	613	1,178
Other Debt Securities [Member]
Unrealized loss position less than 12 months - unrealized loss	(10)	(14)
Unrealized loss position less than 12 months - fair value	354	701
Unrealized loss position 12 months or more - unrealized loss	(2)	(3)
Unrealized loss position 12 months or more - fair value	13	13
Total unrealized loss	(12)	(17)
Total fair value	$ 367	$ 714