Quarterly report pursuant to Section 13 or 15(d)

Long-term Debt - Summary of Debt (Details)

v3.21.2
Long-term Debt - Summary of Debt (Details) - USD ($)
Sep. 30, 2021
Dec. 31, 2020
Dec. 20, 2018
Debt Instrument [Line Items]      
Long-term debt $ 47,213,000 $ 60,495,000  
Current portion of long-term debt 1,750,000 875,000  
Total long-term debt 48,963,000 61,370,000  
Revolving Credit Facility | $150 million revolving line of credit, due January 15, 2025      
Debt Instrument [Line Items]      
Long-term debt 47,213,000 0  
Principal amount of debt 150,000,000    
Revolving Credit Facility | $100 million revolving line of credit, due December 20, 2021      
Debt Instrument [Line Items]      
Long-term debt 0 49,037,000  
Principal amount of debt 100,000,000    
Secured Debt | $20 million term loan, due February 1, 2024      
Debt Instrument [Line Items]      
Long-term debt 0 $ 11,458,000  
Principal amount of debt $ 20,000,000   $ 20,000,000