Consolidated Statement of Comprehensive Income [Abstract]

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- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Amount, after tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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- Definition

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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- Definition

Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (77.2)	$ 44.2	$ (20.0)	$ 41.7	$ 53.3	$ 195.1	$ 58.6	$ 20.9	$ (11.3)	$ 327.9	$ 549.5
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net									(9.1)	(22.2)	31.7
Unrealized losses on derivative contracts, net									(15.4)	(11.7)	(1.7)
Pension and postretirement liability adjustments, net									(150.2)	(74.9)	(21.6)
Amortization of prior service costs and actuarial losses, net									22.3	28.3	17.0
Total other comprehensive (loss) income, net of tax									(152.4)	(80.5)	25.4
Comprehensive (loss) income									$ (163.7)	$ 247.4	$ 574.9