Income Taxes - Components of Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Restructuring reserves	$ 8.4	$ 2.7
Accruals not yet deductible for tax purposes	9.1	10.7
Net operating loss carryforwards	265.5	199.4
Foreign, federal and state credits	10.4	69.2
Employee benefit items	77.0	69.6
Capitalized expenses	8.9	10.8
Derivatives and other	38.0	23.7
Sub-total deferred tax assets	417.3	386.1
Valuation allowance	(218.4)	(189.2)
Total deferred tax assets	198.9	196.9
Depreciation and amortization	(26.8)	(13.9)
Unremitted foreign earnings	0.0	(9.0)
Intangible assets	(21.7)	(26.3)
Other	(0.4)	0.0
Total deferred tax liabilities	(48.9)	(49.2)
Net deferred tax assets	$ 150.0	$ 147.7