Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Raw materials	$ 39,384us-gaap_InventoryRawMaterials	$ 34,153us-gaap_InventoryRawMaterials
Work in process	2,691us-gaap_InventoryWorkInProcess	2,262us-gaap_InventoryWorkInProcess
Finished goods	3,226us-gaap_InventoryFinishedGoods	1,917us-gaap_InventoryFinishedGoods
Inventory, gross	45,301us-gaap_InventoryGross	38,332us-gaap_InventoryGross
Less: Allowance for excess and obsolete inventories	(755)us-gaap_InventoryValuationReserves	(714)us-gaap_InventoryValuationReserves	(583)us-gaap_InventoryValuationReserves	(579)us-gaap_InventoryValuationReserves
Total, net	$ 44,546us-gaap_InventoryNet	$ 37,618us-gaap_InventoryNet

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount of valuation reserve for inventory.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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