| Quarterly Financial Information (Unaudited) |  
		
			19. Quarterly Financial Information (Unaudited)
		 
			
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						2017 |  
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						First | 
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						Second | 
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						Third | 
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						Fourth |  
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						Net sales | 
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						$ | 
						 72,248 | 
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						$ | 
						 139,371 | 
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						$ | 
						 125,339 | 
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						$ | 
						 137,969 |  
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						Gross profit | 
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						$ | 
						 17,187 | 
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						$ | 
						 45,033 | 
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						$ | 
						 36,055 | 
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						$ | 
						 44,811 |  
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						Income (loss) before taxes | 
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						$ | 
						 (5,971) | 
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						$ | 
						 22,354 | 
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						$ | 
						 15,081 | 
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						$ | 
						 21,451 |  
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						Net income (loss) | 
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						$ | 
						 (3,277) | 
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						$ | 
						 14,746 | 
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						$ | 
						 9,327 | 
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						$ | 
						 34,528 |  
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						Basic net earnings (loss) per common share attributable to common shareholders | 
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						$ | 
						 (0.14) | 
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						$ | 
						 0.64 | 
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						$ | 
						 0.41 | 
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						$ | 
						 1.51 |  
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						Earnings (loss) per common share assuming dilution attributable to common shareholders | 
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						$ | 
						 (0.14) | 
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						$ | 
						 0.64 | 
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						$ | 
						 0.40 | 
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						$ | 
						 1.50 |  
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						Dividends per share | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 |  
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			Results for the year ended December 31, 2016 include Dejana which was purchased on July 15, 2016. Additionally, the first quarter of 2016 includes the impact of litigation proceeds of $10,050.
		 
			
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						2016 | 
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						First | 
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						Second | 
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						Third | 
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						Fourth | 
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						Net sales | 
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						$ | 
						 48,789 | 
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						$ | 
						 113,763 | 
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						$ | 
						 123,573 | 
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						$ | 
						 130,143 | 
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						Gross profit | 
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						$ | 
						 14,131 | 
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						$ | 
						 41,521 | 
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						$ | 
						 36,644 | 
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						$ | 
						 41,678 | 
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						Income before taxes | 
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						$ | 
						 8,606 | 
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						$ | 
						 25,551 | 
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						$ | 
						 11,873 | 
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						$ | 
						 17,666 | 
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						Net income  | 
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						$ | 
						 5,278 | 
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						$ | 
						 16,328 | 
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						$ | 
						 7,302 | 
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						$ | 
						 10,101 | 
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						Basic net earnings per common share attributable to common shareholders | 
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						$ | 
						 0.23 | 
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						$ | 
						 0.72 | 
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						$ | 
						 0.32 | 
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						$ | 
						 0.44 | 
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						Earnings per common share assuming dilution attributable to common shareholders | 
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						$ | 
						 0.23 | 
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						$ | 
						 0.71 | 
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						$ | 
						 0.32 | 
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						$ | 
						 0.44 | 
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						Dividends per share | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 | 
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						$ | 
						 0.24 | 
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			Due to changes in stock prices during the year and timing of issuance of shares, the sum of quarterly earnings per share may not equal the annual earnings per share.
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