Condensed Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net (loss) income	$ (736.8)	$ 44.2	$ (936.9)	$ 65.9
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net	17.0	(15.7)	16.2	(20.7)
Unrealized gains (losses) on derivative contracts, net	19.8	(2.5)	31.9	(17.9)
Amortization of prior service costs and actuarial losses, net	8.9	5.9	27.1	16.9
Total other comprehensive income (loss), net of tax	45.7	(12.3)	75.2	(21.7)
Comprehensive (loss) income	$ (691.1)	$ 31.9	$ (861.7)	$ 44.2