(Loss) Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Loss from continuing operations	$ (7.3)	$ (104.6)	$ (28.2)	$ (134.2)
Income (loss) from discontinued operations	0.2	(47.7)	(75.6)	(49.9)
Net loss	$ (7.1)	$ (152.3)	$ (103.8)	$ (184.1)
Denominator:
Weighted average number of common shares outstanding during the period - basic (in shares)	37.1	41.2	37.2	41.1
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)	37.1	41.2	37.2	41.1
Loss per common share — basic:
Continuing operations (in dollars per share)	$ (0.20)	$ (2.54)	$ (0.76)	$ (3.27)
Discontinued operations (in dollars per share)	0.01	(1.16)	(2.03)	(1.21)
Net loss (in dollars per share)	(0.19)	(3.70)	(2.79)	(4.48)
Loss per common share — diluted:
Continuing operations (in dollars per share)	(0.20)	(2.54)	(0.76)	(3.27)
Discontinued operations (in dollars per share)	0.01	(1.16)	(2.03)	(1.21)
Net loss (dollars per share)	$ (0.19)	$ (3.70)	$ (2.79)	$ (4.48)
Anti-dilutive shares excluded from calculation (in shares)	3.5	3.5	4.2	3.5