Inventories - Summary of Inventories, at LIFO Value (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Finished goods	$ 32,756us-gaap_InventoryFinishedGoods	$ 30,423us-gaap_InventoryFinishedGoods
Raw materials	16,290us-gaap_InventoryRawMaterials	16,502us-gaap_InventoryRawMaterials
Total FIFO inventories	49,046us-gaap_InventoryGross	46,925us-gaap_InventoryGross
Reserve to adjust inventories to LIFO value	(25,299)us-gaap_InventoryLIFOReserve	(24,497)us-gaap_InventoryLIFOReserve
Total LIFO inventories	$ 23,747us-gaap_InventoryNet	$ 22,428us-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.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(1))

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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.

+ References

+ Details

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- Definition

Amount of difference between inventory at lower of LIFO cost or market and inventory at lower of other inventory accounting method cost or market, for example, but not limited to, FIFO or average cost.

+ References

+ Details

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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 330

-SubTopic 10

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6386567&loc=d3e3927-108312

Reference 3: http://www.xbrl.org/2003/role/presentationRef

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- Definition

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

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(4))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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