(Loss) Earnings per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Numerator:
Loss from continuing operations	$ (14.4)	$ (61.4)	$ (19.8)	$ (16.8)	$ 19.2	$ (26.2)	$ (1.8)	$ (15.6)	$ (112.4)	[1]	$ (24.4)	[1]	$ (324.8)
Loss from discontinued operations	0	0	(1.6)	(0.7)	(2.5)	(8.7)	(3.3)	(5.5)	(2.3)	[1]	(20.0)	[1]	(15.9)
Net loss	$ (14.4)	$ (61.4)	$ (21.4)	$ (17.5)	$ 16.7	$ (34.9)	$ (5.1)	$ (21.1)	$ (114.7)	[1]	$ (44.4)	[1]	$ (340.7)
Denominator:
Weighted average number of common shares outstanding during the period (in shares)									41.0		40.5		37.5
Dilutive effect of stock-based compensation plans (in shares)									0		0		0
Weighted average number of diluted shares outstanding during the period (in shares)									41.0		40.5		37.5
Basic loss per common share:
Continuing operations (dollars per share)	$ (0.35)	$ (1.49)	$ (0.48)	$ (0.41)	$ 0.47	$ (0.65)	$ (0.04)	$ (0.39)	$ (2.74)	[1]	$ (0.60)	[1]	$ (8.67)
Discontinued operations (dollars per share)	$ 0.00	$ 0.00	$ (0.04)	$ (0.02)	$ (0.06)	$ (0.21)	$ (0.08)	$ (0.14)	$ (0.06)	[1]	$ (0.49)	[1]	$ (0.42)
Net loss (dollars per share)	$ (0.35)	$ (1.49)	$ (0.52)	$ (0.43)	$ 0.41	$ (0.86)	$ (0.13)	$ (0.52)	$ (2.80)	[1]	$ (1.10)	[1]	$ (9.09)
Diluted (loss) earnings per common share:
Continuing operations (dollars per share)	$ (0.35)	$ (1.49)	$ (0.48)	$ (0.41)	$ 0.47	$ (0.65)	$ (0.04)	$ (0.39)	$ (2.74)	[1]	$ (0.60)	[1]	$ (8.67)
Discontinued operations (dollars per share)	$ 0.00	$ 0.00	$ (0.04)	$ (0.02)	$ (0.06)	$ (0.21)	$ (0.08)	$ (0.14)	$ (0.06)	[1]	$ (0.49)	[1]	$ (0.42)
Net loss (dollars per share)	$ (0.35)	$ (1.49)	$ (0.52)	$ (0.43)	$ 0.41	$ (0.86)	$ (0.13)	$ (0.52)	$ (2.80)	[1]	$ (1.10)	[1]	$ (9.09)
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from calculation (in shares)									4.5		6.1		6.3

[1] The sum of the quarterly loss per share may not equal the annual loss per share due to changes in average shares outstanding.