Accumulated Other Comprehensive Loss (Components of accumulated comprehensive loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2017	$ 236.0
Other comprehensive income (loss)	4.1	$ 2.8
March 31, 2017	250.2
Cumulative Translation Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2017	(30.8)	(16.9)
Other comprehensive income (loss)	3.9	2.6
March 31, 2017	(26.9)	(14.3)
Pension and Postretirement Benefits
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2017	(11.9)	(13.1)
Other comprehensive income (loss)	0.2	0.2
March 31, 2017	(11.7)	(12.9)
Total
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2017	(42.7)	(30.0)
March 31, 2017	$ (38.6)	$ (27.2)