Income Taxes - Schedule of Significant Deferred Tax Assets And Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Components Of Deferred Tax Assets And Liabilities [Abstract]
Pension and other postretirement benefits plan liabilities	$ 100.1	$ 120.3
Net operating losses and other tax carryforwards	164.9	156.6
Accrued liabilities	86.1	86.6
Foreign depreciation	14.6	16.6
Other	25.1	30.5
Total deferred tax assets	390.8	410.6
Valuation allowances	(154.1)	(130.8)
Net deferred tax assets	236.7	279.8
Accelerated depreciation	(68.2)	(77.6)
Other intangible assets	(36.0)	(75.7)
Inventories	(7.6)	(11.6)
Other	(23.1)	(28.3)
Total deferred tax liabilities	(134.9)	(193.2)
Net deferred tax assets	$ 101.8	$ 86.6