Deferred Income Tax Assets and Liabilities with Temporary Differences and Carryforwards (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Benefit plans	$ 1,590	$ 1,099
Inventories	525	536
Other	37	38
Total deferred tax assets	2,152	1,673
Deferred tax liabilities:
Property, plant and equipment	9,716	10,299
Patents and goodwill	2,956	2,972
Other	166	11
Total deferred tax liabilities	12,838	13,282
Net deferred tax liability	10,686	11,609
Balance Sheet classification:
Non-current deferred income tax liability	12,062	12,232
Current deferred income tax asset	1,376	623
Net deferred tax liability	$ 10,686	$ 11,609