Earnings per Share (EPS) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1.0		0.6
Reallocation Adjustment For Participating Securities			$ 0.1
EPS numerator:
(Loss) income from continuing operations, net of income taxes	(10.3)		183.0
Net Income Attributable to Noncontrolling Interest	(4.0)		(5.6)
(Loss) income from continuing operations attributable to common stockholders, before allocation of earnings to participating securities	(14.3)		177.4
Less: Earnings from continuing operations allocated to participating securities	0		1.2
(Loss) income from continuing operations attributable to common stockholders, after allocation of earnings to participating securities	(14.3)	[1]	176.2	[1]
Loss from discontinued operations, net of income taxes	(9.1)		(4.7)
Net (loss) income attributable to common stockholders, after aloocation of earnings to participating securities	(23.4)	[1]	171.5	[1]
EPS denominator:
Weighted average shares outstanding - basic	266.9		270.1
Impact of dilutive securities	0		0.8
Weighted average shares outstanding - diluted	266.9		270.9
Basic EPS attributable to common stockholders:
(Loss) income from continuing operations	$ (0.05)		$ 0.65
Loss from discontinued operations	$ (0.04)		$ (0.02)
Net (loss) income	$ (0.09)		$ 0.63
Diluted EPS attributable to common stockholders:
(Loss) income from continuing operations	$ (0.05)		$ 0.65
Loss from discontinued operations	$ (0.04)		$ (0.02)
Net (loss) income	$ (0.09)		$ 0.63
Noncontrolling Interest [Member]
EPS numerator:
Net Income Attributable to Noncontrolling Interest	$ (4.0)

[1] The reallocation adjustment for participating securities to arrive at the numerator used to calculate diluted EPS was less than $0.1 million for the three months ended March 31, 2012.