Income Taxes - Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Employment – related liabilities	$ 10,975	$ 18,659
Liabilities related to discontinued operations	186	241
Capital loss carryforwards	308	282
Asbestos-related liability	12,179	21,024
Net operating loss – domestic	674	653
Net operating loss – state	2,782	2,123
Net operating loss – foreign	22,856	19,106
Inventory related	2,764	2,157
Impairment charge associated with investment in MG	1,155	2,184
Investment tax credits – foreign	848	791
Other	3,181	6,660
Gross deferred income tax assets	68,545	92,254
Valuation allowance	(38,112)	(45,449)
Deferred tax assets, net, Total	30,433	46,805
Liabilities:
Depreciation	(26,915)	(37,584)
Mark-to-market adjustment – derivatives	(4)	(187)
Intangible assets – definite life	(1,186)	(2,067)
Intangible assets – indefinite life	(605)	(731)
Other	(566)	(2,003)
Gross deferred income tax liabilities	(29,276)	(42,572)
Net deferred income tax assets	1,157	4,233
Foreign Tax Authority [Member]
Assets:
Pension liability	1,633	2,241
Domestic Tax Authority [Member]
Assets:
Pension liability	$ 9,004	$ 16,133