Annual report pursuant to Section 13 and 15(d)

Note 3 - Financing Arrangements (Details Textual)

v3.19.2
Note 3 - Financing Arrangements (Details Textual) - USD ($)
9 Months Ended 12 Months Ended
Sep. 19, 2017
May 16, 2017
Dec. 31, 2017
Mar. 31, 2019
Apr. 01, 2018
Sep. 18, 2017
Selling, General and Administrative Expense, Total       $ 15,194,000 $ 14,272,000  
Line of Credit Facility, Remaining Borrowing Capacity       19,400,000 13,200,000  
Revolving Credit Facility [Member]            
Line of Credit Facility, Maximum Borrowing Capacity       26,000,000    
Long-term Line of Credit, Total       4,500,000 9,500,000  
Letters of Credit Outstanding, Amount       $ 0 0  
Revolving Credit Facility [Member] | Prime Rate [Member]            
Debt Instrument Basis Spread Below Variable Rate       0.50%    
Debt Instrument, Basis Spread on Variable Rate       2.00%    
Debt Instrument, Interest Rate, Effective Percentage       3.50%    
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]            
Debt Instrument, Basis Spread on Variable Rate       1.75%    
Debt Instrument, Interest Rate, Effective Percentage       4.24%    
Letter of Credit [Member]            
Line of Credit Facility, Maximum Borrowing Capacity       $ 1,500,000    
Factoring Fees [Member]            
Selling, General and Administrative Expense, Total       $ 261,000 223,000  
Chase Bank N.A. [Member] | Master Stand-by Claims Purchase Agreement [Member]            
Purchase Agreement, Monthly Fee, Percentage of Accounts Receivable   1.65%        
Purchase Agreement, Limit of Accounts Receivable Used in Determination of Monthly Fee   $ 1,800,000        
Selling, General and Administrative Expense, Total     $ 480,000      
Chase Bank N.A. [Member] | Master Stand-by Claims Purchase Agreement [Member] | Other Accounts Receivable [Member]            
Accounts Receivable, after Allowance for Credit Loss, Total           $ 866,000
Chase Bank N.A. [Member] | Master Stand by Claims Second Purchase Agreement [Member]            
Purchase Agreement, Monthly Fee, Percentage of Accounts Receivable 1.50%          
Purchase Agreement, Limit of Accounts Receivable Used in Determination of Monthly Fee $ 1,800,000          
Selling, General and Administrative Expense, Total         $ 173,000