Condensed Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 20.9	$ 13.4
Other comprehensive income, net of tax:
Foreign currency translation adjustments, net	12.4	6.0
Unrealized losses on derivative contracts, net	(0.1)	(2.0)
Amortization of prior service costs and actuarial losses, net	5.4	3.9
Total other comprehensive income, net of tax	17.7	7.9
Comprehensive income	$ 38.6	$ 21.3