Investment Securities (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings				$ (15)
Other Gains (losses)	1	(10)	1	(15)
Available for sale Securities [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings	(40)	(9)	(49)
Other Gains (losses)	1	(10)	1	(15)
Total Available for sale other-than-temporary impairment	(39)	(19)	(48)	(30)
Available for sale Securities [Member] | Other asset-backed securities [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings		(1)	(1)	(1)
Other Gains (losses)			1
Total Available for sale other-than-temporary impairment		(1)		(1)
Available for sale Securities [Member] | Perpetual preferred securities [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings	(27)		(27)
Total Available for sale other-than-temporary impairment	(27)		(27)
Available for sale Securities [Member] | Non-agency [Member] | Commercial [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings	(1)		(1)
Other Gains (losses)			(1)
Total Available for sale other-than-temporary impairment	(1)		(2)
Available for sale Securities [Member] | Residential Non-agency Prime [Member] | Residential [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings	(2)	(1)	(3)	(2)
Other Gains (losses)	(6)	(4)	(9)	(3)
Total Available for sale other-than-temporary impairment	(8)	(5)	(12)	(5)
Available for sale Securities [Member] | Residential Non-agency Non-Prime [Member] | Residential [Member]
Summary of other-than-temporary impairment by investment category
Losses Recorded in Earnings	(10)	(7)	(17)	(12)
Other Gains (losses)	7	(6)	10	(12)
Total Available for sale other-than-temporary impairment	$ (3)	$ (13)	$ (7)	$ (24)