v3.20.4
Long-Term Debt - Credit Agreements (Details) - Line of Credit - Revolving credit facility - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Sep. 29, 2020
ABL Credit Agreement        
Line of Credit Facility [Line Items]        
Total Capacity $ 20,146,000     $ 35,000,000
Amount Borrowed 0      
Outstanding Letters of Credit 0      
Available Capacity 20,146,000      
Deferred financing costs       $ 400,000
Amortization expense $ 200,000 $ 200,000 $ 200,000  
ABL Credit Agreement, Through December 31, 2020 | Base Rate        
Line of Credit Facility [Line Items]        
Basis spread on variable rate (as a percent) 1.00%      
ABL Credit Agreement, After December 31, 2020 | Base Rate | Quarterly Excess Availability Greater Than 50%        
Line of Credit Facility [Line Items]        
Basis spread on variable rate (as a percent) 1.00%      
ABL Credit Agreement, After December 31, 2020 | Base Rate | Quarterly Excess Availability Not Greater Than 50%        
Line of Credit Facility [Line Items]        
Basis spread on variable rate (as a percent) 1.50%