(Loss) 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
Numerator:
Loss from continuing operations	$ (17.4)	$ (19.8)	$ (31.8)	$ (36.6)
Loss from discontinued operations	0.0	(1.6)	0.0	(2.3)
Net loss	$ (17.4)	$ (21.4)	$ (31.8)	$ (38.9)
Denominator:
Weighted average number of common shares outstanding during the period - basic (in shares)	41.1	41.2	41.1	41.0
Dilutive effect of stock-based compensation plans (in shares)	0.0	0.0	0.0	0.0
Weighted average number of diluted shares outstanding during the period - diluted (in shares)	41.1	41.2	41.1	41.0
Loss per common share — basic:
Continuing operations - basic (in dollars per share)	$ (0.42)	$ (0.48)	$ (0.77)	$ (0.89)
Discontinued operations - basic (in dollars per share)	0.00	(0.04)	0.00	(0.06)
Net loss - basic (in dollars per share)	(0.42)	(0.52)	(0.77)	(0.95)
Loss per common share — diluted:
Continuing operations - diluted (in dollars per share)	(0.42)	(0.48)	(0.77)	(0.89)
Discontinued operations - diluted (in dollars per share)	0.00	(0.04)	0.00	(0.06)
Net loss - diluted (dollars per share)	$ (0.42)	$ (0.52)	$ (0.77)	$ (0.95)
Anti-dilutive shares excluded from calculation (in shares)	3.3	4.9	3.5	4.7