Income Taxes - Schedule of Current and Non-Current Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Reserves, Non-current	$ 11,931	$ 7,987
Reserves, Current		5,032
Compensation, Non-current	8,250	5,075
Compensation, Current		3,087
Post-retirement benefits, Non-current	19,476	21,338
Post-retirement benefits, Current		1,531
Property, Non-current	(84,009)	(89,432)
Intangible Assets, Current	0	0
Intangible Assets, Non-current	(17,748)	(21,285)
Pension, Current		532
Pension, Non-current	(26,885)	(30,412)
Inventories, Current		2,758
Inventories, Non-current	3,445
Other		(783)
Other, Non-current	605	1,171
Research & development expenses	8,925
Tax carryforwards, Non-current	8,413	12,660
Tax carryforwards, Current		8,560
Subtotal, Non-current	(67,597)	(92,898)
Subtotal, Current		20,717
Valuation allowance, Non-current	(3,773)	(2,288)
Valuation allowance, Current		(934)
Total, Non-current	$ (71,370)	(95,186)
Total, Current		$ 19,783

Deferred Tax Assets Intangible Assets Current

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Deferred tax assets tax deferred expense compensation and benefits postretirement.

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Deferred tax assets tax deferred expense compensation and benefits share based compensation cost current.

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Deferred tax assets tax deferred expense reserves and accruals reserves current.

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Deferred Tax Liabilities Net Non Current

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Gross amount of noncurrent deferred tax liabilities, which result from applying the applicable tax rate to taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax.

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