CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statement of Comprehensive Income [Abstract]
Net (loss) income	$ 17.5	$ 17.5	$ (1.0)	$ (37.9)	$ (62.7)	$ 5.9	$ 42.3	$ 13.1	$ (3.9)	$ (1.4)	$ 105.7
Other comprehensive loss, net of tax:
Foreign currency translation adjustments, net									(12.0)	(9.8)	(1.8)
Unrealized gains (losses) on derivative contracts, net									19.7	(2.7)	(5.1)
Pension and postretirement liability adjustments, net									(37.5)	(78.8)	(86.6)
Amortization of prior service costs and actuarial losses, net									12.3	41.9	15.5
Total other comprehensive loss, net of tax									(17.5)	(49.4)	(78.0)
Comprehensive (loss) income									$ (21.4)	$ (50.8)	$ 27.7