XML 71 R56.htm IDEA: XBRL DOCUMENT v3.8.0.1
Commitments and Contingencies (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Commitments and Contingencies [Line Items]      
Operating lease rent expense $ 850 $ 1,250 $ 1,515
Royalty expense $ 2,323 $ 1,895 $ 1,799
Minimum [Member]      
Commitments and Contingencies [Line Items]      
Royalty rates 3.00%    
Maximum [Member]      
Commitments and Contingencies [Line Items]      
Royalty rates 5.00%    
Royalty agreement term 20 years    
Office, Manufacturing, Warehouse Facilities, And Equipment [Member]      
Commitments and Contingencies [Line Items]      
Operating leases expire at various terms Dec. 31, 2022