COMMON EQUITY (Details 2) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:
Net income (loss) from continuing operations	$ 39.4	$ 74.3	$ 217.7	$ 224.8
Discontinued operations, net of tax	(0.6)	(8.0)	4.7	(9.2)
Preferred stock dividends of subsidiary	(0.7)	(0.7)	(2.3)	(2.3)
Noncontrolling interest in subsidiaries	0	0.1	0.1	0.1
Net income attributed to common shareholders	38.1	65.7	220.2	213.4
Dilutive Securities, Effect on Basic Earnings Per Share	(0.1)	0	(0.1)	0
Net income (loss) attributed to common shareholders, diluted	$ 38.0	$ 65.7	$ 220.1	$ 213.4
Denominator:
Average shares of common stock - basic	79.8	78.5	79.3	78.5
Effect of dilutive securities - Stock-based compensation (in shares)	0.4	0.6	0.4	0.6
Effect of dilutive securities - Deferred compensation (in shares)	0	0.2	0.2	0.2
Average shares of common stock - diluted	80.2	79.3	79.9	79.3
Earnings (Loss) per common share
Basic (in dollars per share)	$ 0.48	$ 0.84	$ 2.78	$ 2.72
Diluted (in dollars per share)	$ 0.47	$ 0.83	$ 2.76	$ 2.69
Stock-based compensation
Disclosure of antidilutive shares
Antidilutive shares excluded from calculation of diluted earnings per share	0.4	0.9	0.2	0.6
Deferred compensation
Disclosure of antidilutive shares
Antidilutive shares excluded from calculation of diluted earnings per share	0.2	0	0.1	0