Investment Securities (Details 7) (USD $) In Millions	Jun. 30, 2011
Available-for-sale
Fair Value Less Than 12 Months	$ 11,554
Unrealized Losses Less Than 12 Months	(133)
Fair Value 12 Months or Greater	3,756
Unrealized Losses 12 Months or Greater	(554)
Fair Value Total	15,310
Unrealized Losses Total	(687)
Held-to-maturity
Fair Value Less Than 12 Months	1,532
Unrealized Losses Less Than 12 Months	(5)
Fair Value 12 Months or Greater	169
Unrealized Losses 12 Months or Greater	(44)
Fair Value Total	1,701
Unrealized Losses Total	(49)
Agency [Member] | Residential [Member]
Held-to-maturity
Fair Value Less Than 12 Months	1,427
Unrealized Losses Less Than 12 Months	(4)
Fair Value 12 Months or Greater	0
Unrealized Losses 12 Months or Greater	0
Fair Value Total	1,427
Unrealized Losses Total	(4)
Agency [Member] | Residential [Member]
Available-for-sale
Fair Value Less Than 12 Months	7,170
Unrealized Losses Less Than 12 Months	(46)
Fair Value 12 Months or Greater	54
Unrealized Losses 12 Months or Greater	0
Fair Value Total	7,224
Unrealized Losses Total	(46)
Agency [Member] | Commercial Mortgage Backed Securities [Member]
Available-for-sale
Fair Value Less Than 12 Months	14
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	0
Unrealized Losses 12 Months or Greater	0
Fair Value Total	14
Unrealized Losses Total	0
Non-agency [Member] | Commercial Mortgage Backed Securities [Member]
Held-to-maturity
Fair Value Less Than 12 Months	0
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	3
Unrealized Losses 12 Months or Greater	(3)
Fair Value Total	3
Unrealized Losses Total	(3)
Non-agency [Member] | Commercial Mortgage Backed Securities [Member]
Available-for-sale
Fair Value Less Than 12 Months	4
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	1
Unrealized Losses 12 Months or Greater	(1)
Fair Value Total	5
Unrealized Losses Total	(1)
Non agency Prime [Member] | Residential [Member]
Available-for-sale
Fair Value Less Than 12 Months	97
Unrealized Losses Less Than 12 Months	(4)
Fair Value 12 Months or Greater	726
Unrealized Losses 12 Months or Greater	(93)
Fair Value Total	823
Unrealized Losses Total	(97)
Non agency Non Prime [Member] | Residential [Member]
Held-to-maturity
Fair Value Less Than 12 Months	0
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	2
Unrealized Losses 12 Months or Greater	0
Fair Value Total	2
Unrealized Losses Total	0
Non agency Non Prime [Member] | Residential [Member]
Available-for-sale
Fair Value Less Than 12 Months	56
Unrealized Losses Less Than 12 Months	(6)
Fair Value 12 Months or Greater	722
Unrealized Losses 12 Months or Greater	(228)
Fair Value Total	778
Unrealized Losses Total	(234)
Other Investments [Member]
Available-for-sale
Fair Value Less Than 12 Months	1
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	3
Unrealized Losses 12 Months or Greater	0
Fair Value Total	4
Unrealized Losses Total	0
U.S. Treasury and agency [Member]
Held-to-maturity
Fair Value Less Than 12 Months	104
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	0
Unrealized Losses 12 Months or Greater	0
Fair Value Total	104
Unrealized Losses Total	0
U.S. Treasury and agency [Member]
Available-for-sale
Fair Value Less Than 12 Months	685
Unrealized Losses Less Than 12 Months	(4)
Fair Value 12 Months or Greater	0
Unrealized Losses 12 Months or Greater	0
Fair Value Total	685
Unrealized Losses Total	(4)
Obligations of state and political subdivisions [Member]
Held-to-maturity
Fair Value Less Than 12 Months	0
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	9
Unrealized Losses 12 Months or Greater	(1)
Fair Value Total	9
Unrealized Losses Total	(1)
Obligations of state and political subdivisions [Member]
Available-for-sale
Fair Value Less Than 12 Months	3,177
Unrealized Losses Less Than 12 Months	(66)
Fair Value 12 Months or Greater	1,214
Unrealized Losses 12 Months or Greater	(99)
Fair Value Total	4,391
Unrealized Losses Total	(165)
Collateralized Debt Obligations [Member]
Held-to-maturity
Fair Value Less Than 12 Months	1
Unrealized Losses Less Than 12 Months	(1)
Fair Value 12 Months or Greater	41
Unrealized Losses 12 Months or Greater	(8)
Fair Value Total	42
Unrealized Losses Total	(9)
Collateralized Debt Obligations [Member]
Available-for-sale
Fair Value Less Than 12 Months	11
Unrealized Losses Less Than 12 Months	(3)
Fair Value 12 Months or Greater	7
Unrealized Losses 12 Months or Greater	(1)
Fair Value Total	18
Unrealized Losses Total	(4)
Others [Member]
Held-to-maturity
Fair Value Less Than 12 Months	0
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	15
Unrealized Losses 12 Months or Greater	(7)
Fair Value Total	15
Unrealized Losses Total	(7)
Others [Member]
Available-for-sale
Fair Value Less Than 12 Months	61
Unrealized Losses Less Than 12 Months	(1)
Fair Value 12 Months or Greater	76
Unrealized Losses 12 Months or Greater	(11)
Fair Value Total	137
Unrealized Losses Total	(12)
Corporate Debt Securities [Member]
Available-for-sale
Fair Value Less Than 12 Months	205
Unrealized Losses Less Than 12 Months	(2)
Fair Value 12 Months or Greater	691
Unrealized Losses 12 Months or Greater	(86)
Fair Value Total	896
Unrealized Losses Total	(88)
Perpetual preferred securities [Member]
Available-for-sale
Fair Value Less Than 12 Months	73
Unrealized Losses Less Than 12 Months	(1)
Fair Value 12 Months or Greater	262
Unrealized Losses 12 Months or Greater	(35)
Fair Value Total	335
Unrealized Losses Total	(36)
Other Debt Securities [Member]
Held-to-maturity
Fair Value Less Than 12 Months	0
Unrealized Losses Less Than 12 Months	0
Fair Value 12 Months or Greater	99
Unrealized Losses 12 Months or Greater	(25)
Fair Value Total	99
Unrealized Losses Total	$ (25)