Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets related to:
Expenses not yet deducted for tax purposes	$ 256,728	$ 344,927
Net operating loss	257,766	397,391
Net operating loss	31,046	4,673
Net deferred tax assets, gross	545,540	746,991
Deferred tax liabilities related to:
Employee and retiree benefits	210,429	276,256
Inventory	93,067	141,181
Other intangible assets	287,018	120,689
Property, plant, and equipment	66,727	61,666
Other	35,859	58,468
Deferred tax liabilities, total	693,100	658,260
Net deferred tax (liability) asset before valuation allowance	(147,560)	88,731
Valuation allowance	(5,590)	(4,405)
Total net deferred tax liability	$ (153,150)
Total net deferred tax asset		$ 84,326