Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current deferred tax assets:
Inventory	$ 7,457	$ 12,466
Federal tax carryforwards	11,774	12,418
Share-based compensation	2,271	2,000
Receivables	684	765
Accrued liabilities	746	679
Other	65	348
Total current deferred tax assets	22,997	28,676
Noncurrent deferred tax assets:
Federal and state tax carryforwards	4,640	4,498
Deferred tax liabilities:
Property, plant and equipment (noncurrent)	59,867	52,789
Other (current)	258	238
Deferred Tax Liabilities, Net, Total	$ 60,125	$ 53,027