Accumulated Other Comprehensive Loss (Components of accumulated comprehensive loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			$ 212.2
Other comprehensive income (loss)	$ (6.3)	$ 2.8	(3.5)	$ (2.3)
Ending balance	221.2		221.2
Cumulative Translation Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(16.9)	(5.1)
Other comprehensive income (loss)			(3.9)	(2.6)
Ending balance	(20.8)	(7.7)	(20.8)	(7.7)
Pension and OPEB
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(13.1)	(8.9)
Other comprehensive income (loss)			0.4	0.3
Ending balance	(12.7)	(8.6)	(12.7)	(8.6)
Total
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(30.0)	(14.0)
Ending balance	$ (33.5)	$ (16.3)	$ (33.5)	$ (16.3)