Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Narrative) (Details)

v3.21.1
Commitments and Contingencies (Narrative) (Details)
12 Months Ended
Oct. 29, 2020
USD ($)
item
Dec. 31, 2020
USD ($)
shares
Dec. 31, 2019
USD ($)
shares
Commitments and Contingencies [Line Items]      
(Income) expense for long-term compensation plan   $ 66,000 $ 164,000
Accrual for long-term compensation plans   $ 230,000 $ 164,000
Long-Term Compensation Plan [Member]      
Commitments and Contingencies [Line Items]      
Award payouts, stock | shares   0 0
Award payouts, cash   $ 0 $ 0
2018 to 2020 Plans [Member]      
Commitments and Contingencies [Line Items]      
Percentage paid out in stock   50.00%  
Percentage paid out in cash   50.00%  
2019 to 2021 and 2020 to 2022 Plans [Member]      
Commitments and Contingencies [Line Items]      
Percentage paid out in stock   75.00%  
Percentage paid out in cash   25.00%  
Line of Credit [Member]      
Commitments and Contingencies [Line Items]      
Line of credit, maximum borrowing capacity   $ 5,000,000  
Line of credit, amount outstanding   0 $ 0
Line of credit, remaining borrowing capacity   $ 1,051,000  
Line of credit facility, interest rate at period end   2.00%  
Line of credit, expiration date   Aug. 28, 2021  
Line of Credit [Member] | Minimum [Member]      
Commitments and Contingencies [Line Items]      
Ability to obtain letter of credit, number of letters of credit | item 1    
Letter of Credit [Member]      
Commitments and Contingencies [Line Items]      
Line of credit, maximum borrowing capacity $ 2,000,000    
LIBOR [Member] | Line of Credit [Member]      
Commitments and Contingencies [Line Items]      
Line of credit, basis spread on variable rate   1.25%  
LIBOR [Member] | Line of Credit [Member] | Minimum [Member]      
Commitments and Contingencies [Line Items]      
Line of credit, basis spread on variable rate   0.75%