Condensed Statements of Comprehensive Income (Loss) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]        
Net income (loss) $ 58.6 $ (5.9) $ 79.5 $ 7.5
Other comprehensive (loss) income, net of tax:        
Foreign currency translation adjustments, net (26.1) 15.9 (13.7) 21.9
Unrealized losses on derivative contracts, net (2.4) (3.7) (2.5) (5.7)
Amortization of prior service costs and actuarial losses, net 8.1 4.5 13.5 8.4
Total other comprehensive (loss) income, net of tax (20.4) 16.7 (2.7) 24.6
Comprehensive income $ 38.2 $ 10.8 $ 76.8 $ 32.1