Current report of foreign issuer pursuant to Rules 13a-16 and 15d-16 Amendments

Revenues (Schedule of Disaggregation of Revenues Based on Time) (Details)

v3.19.2
Revenues (Schedule of Disaggregation of Revenues Based on Time) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Disaggregation of Revenue [Line Items]        
Total Revenues $ 163,163 $ 170,236 $ 318,463 $ 324,069
Revenues recognized in point in time [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 121,088 129,462 236,806 243,457
Revenues recognized over time [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 42,075 40,774 81,657 80,612
Products [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 110,341 118,403 215,432 222,320
Products [Member] | Revenues recognized in point in time [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 110,341 118,403 215,432 222,320
Services [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 52,822 51,833 103,031 101,749
Services [Member] | Revenues recognized in point in time [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues 10,747 11,059 21,374 21,137
Services [Member] | Revenues recognized over time [Member]        
Disaggregation of Revenue [Line Items]        
Total Revenues $ 42,075 $ 40,774 $ 81,657 $ 80,612