Earnings (Loss) Per Common Share (Details) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Income (loss) from Continuing Operations
Income from continuing operations, net of tax	$ 104	$ 175	$ 453	$ 495
Less: Preferred stock dividends and accretion of discount	11	11	21	494
Income from continuing operations, net of tax, available to common shareholders	93	164	432	1
Add: Dilutive effect of preferred stock dividends
Income from continuing operations, net of tax, available to common shareholders and assumed conversion of preferred shares	93	164	432	1
Income (Loss) from discontinued operations, net of tax	(80)	(99)	82	(100)
Net income
Net income	24	76	535	395
Less: Preferred stock dividends and accretion of discount	11	11	21	494
Net income (loss) available to common shareholders	13	65	514	(99)
Add: Dilutive effect of preferred stock dividends
Net income (loss) available to common shareholders and assumed conversion of preferred shares	$ 13	$ 65	$ 535	$ (99)
Shares
Weighted average common shares outstanding, basic	445.1	443.9	444.9	418.8
Diluted effect of warrants	36.3	35.2	38.6
Diluted effect of stock compensation plans	1.0	1.1	1.4
Diluted effect of mandatory convertible preferred shares			20.7
Weighted average shares outstanding and dilutive potential common shares	482.4	480.2	505.6	418.8
Basic
Income from continuing operations, net of tax, available to common shareholders	$ 0.21	$ 0.37	$ 0.97
Income (loss) from discontinued operations, net of tax	$ (0.18)	$ (0.22)	$ 0.19	$ (0.24)
Net income (loss) available to common shareholders	$ 0.03	$ 0.15	$ 1.16	$ (0.24)
Diluted
Income from continuing operations, net of tax, available to common shareholders	$ 0.19	$ 0.34	$ 0.89
Income (loss) from discontinued operations, net of tax	$ (0.16)	$ (0.20)	$ 0.17	$ (0.24)
Net income (loss) available to common shareholders	$ 0.03	$ 0.14	$ 1.06	$ (0.24)