Annual report pursuant to Section 13 and 15(d)

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

v3.20.1
Nature Of Operations And Summary Of Significant Accounting Policies (Details) - USD ($)
12 Months Ended 36 Months Ended
Jan. 24, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2019
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Aggregate cost of tender offer   $ 4,167,000 $ 5,687,000 $ 17,000  
Contract liabilities   141,000 90,000   $ 141,000
Revenue recognized from satisfaction of performance obligations   $ 90,000 554,000    
Accounts receivable write-off         $ 0
Dividend annualized   $ 0.10     $ 0.10
Dividend per quarter   $ 0.025      
Dividends   $ 2,987,000 $ 1,488,000    
Dividends per share   $ 0.10 $ 0.05    
Goodwill impairment         $ 0
Indefinite-lived intangible asset impairment         0
Accrued liabilities   $ 9,559,000 $ 7,446,000   9,559,000
Stock options, term of expiration   10 years      
Advertising expense   $ 4,588,000 4,016,000 3,951,000  
Cooperative advertising expense   287,000 338,000 537,000  
Reserve for product warranty   1,155,000 1,032,000   1,155,000
Warranty claims   1,123,000 999,000 949,000  
Research and development costs   10,575,000 $ 9,471,000 $ 7,984,000  
Present value of future minimum lease payments   1,181,000     1,181,000
ROU asset   1,200,000     $ 1,200,000
Modified Dutch Auction [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Per share cost of tender offer     $ 8.00    
Number of shares acquired in tender offer     417,237    
Aggregate cost of tender offer     $ 3,338,000    
Authorized Stock Repurchase Program [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Aggregate cost of tender offer   $ 4,167,000 2,349,000    
ASU 2016-02 [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
ROU asset     $ 1,516,000    
Minimum [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Term available for extension   1 year     1 year
Maximum [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Term available for extension   5 years     5 years
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      
Customer Concentration Risk [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Concentration risk, percentage     15.00%    
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Concentration risk, percentage   14.00% 12.00% 14.00%  
Customer Concentration Risk [Member] | Accounts Receivable [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Concentration risk, percentage   14.00%      
Subsequent Event [Member]          
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]          
Dividends     $ 1,488,000    
Dividends per share $ 0.025        
Dividend date declared Jan. 24, 2020        
Dividend date of record Feb. 03, 2020        
Dividend date to be paid Feb. 14, 2020