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           3. INVENTORIES (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        
           Jun. 30, 2013 
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           Dec. 31, 2012 
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|---|---|---|
| Inventory balances | ||
| Finished goods | $ 12,869 | $ 10,230 | 
| Work in progress | 4,270 | 3,846 | 
| Raw materials | 1,152 | 1,363 | 
| Other | 857 | 805 | 
| Total | $ 19,148 | $ 16,244 | 
| X | ||||||||||
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- Definition 
          Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Details 
          
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| X | ||||||||||
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
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- Definition 
          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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Definition 
          Amount before valuation and LIFO reserves of other supplies used within the manufacturing or production process expected to be consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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