CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (969.9)	$ (11.3)	$ 327.9
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net	27.8	(9.1)	(22.2)
Unrealized gains (losses) on derivative contracts, net	35.0	(15.4)	(11.7)
Pension and postretirement liability adjustments, net	14.8	(150.2)	(74.9)
Amortization of prior service costs and actuarial losses, net	35.9	22.3	28.3
Total other comprehensive income (loss), net of tax	113.5	(152.4)	(80.5)
Comprehensive (loss) income	$ (856.4)	$ (163.7)	$ 247.4