Accumulated Other Comprehensive Income (Loss) (Components of accumulated comprehensive loss) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	$ (14.0)	$ 3.4
Cumulative Translation Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	2.8	5.4	4.8
Foreign currency translation adjustments	(7.9)	(2.6)	0.6
Recognition of actuarial gain	0	0	0
Tax adjustment	0	0	0
Recognition of actuarial gain, net	0	0	0
Balance	(5.1)	2.8	5.4
Pension and Postretirement Benefits
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	0.6	(12.2)	(13.2)
Foreign currency translation adjustments	0	0	0
Recognition of actuarial gain	(14.9)	19.9	1.6
Tax adjustment	5.4	(7.1)	(0.6)
Recognition of actuarial gain, net	(9.5)	12.8	1.0
Balance	(8.9)	0.6	(12.2)
Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	3.4	(6.8)	(8.4)
Foreign currency translation adjustments	(7.9)	(2.6)	0.6
Recognition of actuarial gain	(14.9)	19.9	1.6
Tax adjustment	5.4	(7.1)	(0.6)
Recognition of actuarial gain, net	(9.5)	12.8	1.0
Balance	$ (14.0)	$ 3.4	$ (6.8)