Annual report pursuant to Section 13 and 15(d)

Nature Of Operations And Summary Of Significant Accounting Policies (Details)

v3.8.0.1
Nature Of Operations And Summary Of Significant Accounting Policies (Details) - USD ($)
$ in Thousands
 12 Months Ended 36 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2017
Oct. 07, 2015
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Accounts receivable,allowance for doubtful accounts $ 382 $ 399   $ 382  
Advertising expense 3,951 2,605 $ 3,220    
Cooperative advertising expense 537 741 1,037    
Reserve for product warranty 987 892   987  
Warranty claims 949 1,051 813    
Research and development costs 7,984 6,598 7,469    
Available-for-sale Securities, Gross Unrealized Loss     107    
Available-for-sale Securities, Gross Realized Gains   $ 241      
Available-for-sale Securities, Amortized Cost Basis $ 9,994     $ 9,994  
Available-for-sale Securities, Gross Unrealized Loss, tax     $ 63    
Maximum [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Sales returns as percentage of net sales       3.00%  
Building Improvements [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Estimated useful Life 20 years        
Machinery and Equipment [Member] | Minimum [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Estimated useful Life 3 years        
Machinery and Equipment [Member] | Maximum [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Estimated useful Life 10 years        
Furniture and Fixtures [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Estimated useful Life 5 years        
Sales Revenue, Goods, Net [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Concentration risk, percentage     17.00%    
Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Concentration risk, percentage 14.00% 16.00% 17.00%    
POC [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Disposal Group, Including Discontinued Operation, Consideration     $ 63,639   $ 63,639
Subsequent Event [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Operating Lease, Liability $ 800     $ 800