Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Reserves	$ 991	$ 3,720
Environmental	5,696	10,795
Compensation	3,287	3,957
Post-retirement benefits	1,619	2,133
Research & development expenses	6,439
Inventories	(91)	(35)
Tax carryforwards	25,227	21,843
Other	1,117	3,506
Deferred tax assets	44,285	45,919
Valuation allowance	(28,485)	(30,029)
Net deferred tax assets	15,800	15,890
Property	(65,027)	(66,426)
Intangible assets	(19,355)	(22,231)
Pension	(6,198)	(3,890)
Other	(1,577)	(1,935)
Deferred tax liabilities	(92,157)	(94,482)
Net deferred tax liabilities	$ (76,357)	$ (78,592)