Income Taxes - Components of Net Deferred Tax Asset (Liability) (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Tax effect of temporary differences related to:
Inventories	$ 4.2	$ 3.7
Accrued OPEB costs	3.7	4.0
Accrued pension costs	52.6	44.0
Currency revaluation on intercompany debt	24.0	18.6
Accrued environmental liabilities	41.1	39.9
Other deductible differences	43.0	45.7
Tax loss and tax credit carryforwards	143.8	154.3
Valuation allowance	(173.4)	(168.9)
Adjusted gross deferred tax assets (liabilities)	139.0	141.3
Netting of items by tax jurisdiction, assets	(137.8)	(140.0)
Net noncurrent deferred tax asset (liability)	1.2	1.3
Tax effect of temporary differences related to:
Inventories	(4.0)	(3.7)
Marketable securities	(59.9)	(98.2)
Property and equipment	(91.9)	(96.6)
Other taxable differences	(18.9)	(21.7)
Investments in subsidiaries and affiliates	(235.3)	(238.8)
Tax on unremitted earnings of non-U.S. subsidiaries	(2.8)	(2.0)
Adjusted gross deferred tax assets (liabilities)	(412.8)	(461.0)
Netting of items by tax jurisdiction, liabilities	(137.8)	(140.0)
Net noncurrent deferred tax asset (liability)	$ (275.0)	$ (321.0)