Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnings Per Share, Diluted	$ 0.89	$ 0.53	$ 1.12	$ 0.55
Income (Loss) from Continuing Operations, Per Diluted Share	0.84	0.58	0.84	0.59
Diluted earnings (loss) per common share from discontinued operations	0.05	(0.05)	0.28	(0.04)
Income (Loss) from Continuing Operations, Per Basic Share	0.85	0.58	0.84	0.60
Basic earnings (loss) per common share from discontinued operations	$ 0.05	$ (0.04)	$ 0.29	$ (0.04)
Numerator:
Net income (loss)	$ 191.6	$ 114.2	$ 240.8	$ 121.2
Preferred stock dividends	2.6	2.6	5.2	5.2
Net income (loss) applicable to common shareowners - basic and diluted	$ 189.0	$ 111.6	$ 235.6	$ 116.0
Denominator:
Weighted average common shares outstanding - basic	209.7	208.5	209.4	208.2
Stock-based compensation arrangements	0.4	0.9	0.7	1.0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	4.5	0.0
Weighted average common shares outstanding - diluted	214.6	209.4	210.1	209.2
Basic and diluted earnings (loss) per common share	$ 0.90	$ 0.54	$ 1.13	$ 0.56
Discontinued Operations [Member]
Numerator:
Net income (loss)	$ 10.9	$ (9.5)	$ 59.8	$ (8.4)
Preferred stock dividends	0.0	0.0	0.0	0.0
Net income (loss) applicable to common shareowners - basic and diluted	$ 10.9	$ (9.5)	$ 59.8	$ (8.4)
Denominator:
Weighted average common shares outstanding - basic	209.7	208.5	209.4	208.2
Stock-based compensation arrangements	0.4	0.9	0.7	1.0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	4.5	0.0
Weighted average common shares outstanding - diluted	214.6	209.4	210.1	209.2
Continuing Operations [Member]
Numerator:
Net income (loss)	$ 180.7	$ 123.7	$ 181.0	$ 129.6
Preferred stock dividends	2.6	2.6	5.2	5.2
Net income (loss) applicable to common shareowners - basic and diluted	$ 178.1	$ 121.1	$ 175.8	$ 124.4
Denominator:
Weighted average common shares outstanding - basic	209.7	208.5	209.4	208.2
Stock-based compensation arrangements	0.4	0.9	0.7	1.0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	4.5	0.0
Weighted average common shares outstanding - diluted	214.6	209.4	210.1	209.2
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3.4	3.2	3.7	3.5
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		4.5	4.5	4.5

The amount of net income or loss for the period in instances when the basic and diluted net income or loss available to common stockholders are the same amount and reported as a single line item on the face of the financial statements. Basic net income (loss) available to common stockholders is net income or loss after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period). Diluted net income (loss) available to common stockholders is net income or loss plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

No definition available.