Annual report pursuant to Section 13 and 15(d)

Accumulated Other Comprehensive Income (Reclassification Out Of Accumulated Other Comprehensive Income) (Details)

v3.8.0.1
Accumulated Other Comprehensive Income (Reclassification Out Of Accumulated Other Comprehensive Income) (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Sales $ 52,677 $ 45,774 $ 30,680 $ 41,556 $ 41,399 $ 39,441 $ 29,142 $ 38,207 $ 170,687 $ 148,189 $ 155,266
Less: Income tax expense                 (5,087) 665 $ 47,692
Total reclassificaitons from AOCI                 878    
Unrealized Gains (Losses) on Cash Flow Hedges [Member]                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Total reclassificaitons from AOCI                 1,080    
Foreign Currency Translation Adjustments [Member]                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Total reclassificaitons from AOCI                 (202)    
Reclassification Out Of Accumulated Other Comprehensive Income [Member]                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Sales                 (450) $ (351)  
Less: Income tax expense                 630    
Total reclassificaitons from AOCI                 (878)    
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Cash Flow Hedges [Member]                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Sales                 (450)    
Total reclassificaitons from AOCI                 1,080    
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustments [Member]                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Other, net                 $ 202