Earnings (Loss) Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Basic
Income from continuing operations, net of tax, available to common shareholders	$ 1.10	$ (0.57)
Income (loss) from discontinued operations, net of tax	$ 0.00	$ (0.01)
Net income (loss) available to common shareholders	$ 1.10	$ (0.58)
Diluted
Income from continuing operations, net of tax, available to common shareholders	$ 1.03	$ (0.57)
Income (loss) from discontinued operations, net of tax	$ 0.00	$ (0.01)
Net income available to common shareholders	$ 1.03	$ (0.58)
Reconciliation of Net Income Loss Used in Calculating Basic Earnings Loss Per Common Share [Abstract]
Income from continuing operations, net of tax	$ 495	$ (240)
Less: Preferred stock dividends	0	10
Income from continuing operations, net of tax, available to common shareholders	495	(250)
Income (loss) from discontinued operations, net of tax	0	(1)
Reconciliation of Net Income Loss Used in Calculating Diluted Earnings Loss Per Common Share [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	495	(241)
Less: Preferred stock dividends	0
Net income (loss) available to common shareholders	$ 495	$ (251)
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average common shares outstanding, basic	449.8	436.3
Dilutive effect of warrants	22.6	0
Dilutive effect of stock compensation plans	6.2	0
Weighted average shares outstanding and dilutive potential common shares	478.6	436.3