Securities Available for Sale, Gross Unrealized Losses and Fair Value (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	$ (301)	$ (553)
Less than 12 months, Fair Value	25,318	20,456
12 months or more, Gross Unrealized Losses	(1,637)	(2,158)
12 months or more, Fair Value	13,963	14,205
Total Gross Unrealized Losses	(1,938)	(2,711)
Total, Fair Value	39,281	34,661
Debt Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(293)	(512)
Less than 12 months, Fair Value	24,990	19,494
12 months or more, Gross Unrealized Losses	(1,570)	(2,109)
12 months or more, Fair Value	13,146	13,731
Total Gross Unrealized Losses	(1,863)	(2,621)
Total, Fair Value	38,136	33,225
US Treasury and Government [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(13)	(15)
Less than 12 months, Fair Value	7,267	544
12 months or more, Gross Unrealized Losses	0	0
12 months or more, Fair Value	0	0
Total Gross Unrealized Losses	(13)	(15)
Total, Fair Value	7,267	544
US States and Political Subdivisions [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(124)	(322)
Less than 12 months, Fair Value	5,237	6,242
12 months or more, Gross Unrealized Losses	(439)	(515)
12 months or more, Fair Value	3,576	2,720
Total Gross Unrealized Losses	(563)	(837)
Total, Fair Value	8,813	8,962
Mortgage Backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(97)	(139)
Less than 12 months, Fair Value	7,138	9,567
12 months or more, Gross Unrealized Losses	(743)	(1,081)
12 months or more, Fair Value	8,183	9,641
Total Gross Unrealized Losses	(840)	(1,220)
Total, Fair Value	15,321	19,208
Federal agencies [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(19)	(95)
Less than 12 months, Fair Value	4,045	8,103
12 months or more, Gross Unrealized Losses	(7)	(1)
12 months or more, Fair Value	676	60
Total Gross Unrealized Losses	(26)	(96)
Total, Fair Value	4,721	8,163
Residential [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(39)	(35)
Less than 12 months, Fair Value	1,751	1,023
12 months or more, Gross Unrealized Losses	(279)	(454)
12 months or more, Fair Value	3,571	4,440
Total Gross Unrealized Losses	(318)	(489)
Total, Fair Value	5,322	5,463
Commercial [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(39)	(9)
Less than 12 months, Fair Value	1,342	441
12 months or more, Gross Unrealized Losses	(457)	(626)
12 months or more, Fair Value	3,936	5,141
Total Gross Unrealized Losses	(496)	(635)
Total, Fair Value	5,278	5,582
Corporate debt securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(16)	(10)
Less than 12 months, Fair Value	1,291	477
12 months or more, Gross Unrealized Losses	(59)	(27)
12 months or more, Fair Value	227	157
Total Gross Unrealized Losses	(75)	(37)
Total, Fair Value	1,518	634
Collateralized debt obligations [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(25)	(13)
Less than 12 months, Fair Value	1,933	679
12 months or more, Gross Unrealized Losses	(161)	(216)
12 months or more, Fair Value	501	456
Total Gross Unrealized Losses	(186)	(229)
Total, Fair Value	2,434	1,135
Other Debt Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(18)	(13)
Less than 12 months, Fair Value	2,124	1,985
12 months or more, Gross Unrealized Losses	(168)	(270)
12 months or more, Fair Value	659	757
Total Gross Unrealized Losses	(186)	(283)
Total, Fair Value	2,783	2,742
Equity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(8)	(41)
Less than 12 months, Fair Value	328	962
12 months or more, Gross Unrealized Losses	(67)	(49)
12 months or more, Fair Value	817	474
Total Gross Unrealized Losses	(75)	(90)
Total, Fair Value	1,145	1,436
Perpetual preferred securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(5)	(41)
Less than 12 months, Fair Value	303	962
12 months or more, Gross Unrealized Losses	(67)	(48)
12 months or more, Fair Value	817	467
Total Gross Unrealized Losses	(72)	(89)
Total, Fair Value	1,120	1,429
Other equity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Gross Unrealized Losses	(3)	0
Less than 12 months, Fair Value	25	0
12 months or more, Gross Unrealized Losses	0	(1)
12 months or more, Fair Value	0	7
Total Gross Unrealized Losses	(3)	(1)
Total, Fair Value	$ 25	$ 7