Earnings (Loss) Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Basic
Income from continuing operations, net of tax, available to common shareholders	$ (0.25)	$ 0.23	$ (0.05)	$ 0.97
Income (loss) from discontinued operations, net of tax	$ (0.01)	$ (0.18)	$ (0.01)	$ 0.18
Net income (loss) available to common shareholders	$ (0.26)	$ 0.05	$ (0.06)	$ 1.15
Diluted
Income from continuing operations, net of tax, available to common shareholders	$ (0.25)	$ 0.21	$ (0.05)	$ 0.89
Income (loss) from discontinued operations, net of tax	$ (0.01)	$ (0.16)	$ (0.01)	$ 0.17
Net income available to common shareholders	$ (0.26)	$ 0.05	$ (0.06)	$ 1.06
Shares
Weighted average common shares outstanding, basic	438.2	445.1	439.4	444.9
Dilutive effect of warrants		36.3		38.6
Dilutive effect of stock compensation plans		1.0		1.4
Dilutive effect of mandatory convertible preferred shares				20.7
Weighted average shares outstanding and dilutive potential common shares	438.2	482.4	439.4	505.6
Net income
Net income (loss)	$ (101)	$ 33	$ (5)	$ 534
Net income (loss) available to common shareholders	(112)	22	(26)	513
Add: Dilutive effect of preferred stock dividends
Net income (loss) available to common shareholders and assumed conversion of preferred shares	(112)	22	(26)	534
Income (loss) from discontinued operations, net of tax	(1)	(80)	(2)	82
Income from continuing operations
Income from continuing operations, net of tax	(100)	113	(3)	452
Less: Preferred stock dividends	11	11	21	21
Income from continuing operations, net of tax, available to common shareholders	(111)	102	(24)	431
Add: Dilutive effect of preferred stock dividends
Income from continuing operations, net of tax, available to common shareholders and assumed conversion of preferred shares	(111)	102	(24)	431
Income (loss) from continuing operations, net of tax [Member]
Net income
Add: Dilutive effect of preferred stock dividends
Income from continuing operations
Add: Dilutive effect of preferred stock dividends
Net Income [Member]
Net income
Add: Dilutive effect of preferred stock dividends				21
Income from continuing operations
Add: Dilutive effect of preferred stock dividends				$ 21