Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments (Narrative) (Details)

v3.20.1
Derivative Financial Instruments (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Maximum net exposure to company                 $ 45    
Sales $ 61,022 $ 60,203 $ 46,994 $ 61,218 $ 57,307 $ 55,686 $ 45,881 $ 53,267 229,437 $ 212,141 $ 170,687
Reclassification Out Of Accumulated Other Comprehensive Income [Member]                      
Sales                 1,017 256  
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Cash Flow Hedges [Member]                      
Sales                 $ 1,017 $ 256