Quarterly report pursuant to Section 13 or 15(d)

Revolving Credit Facility (Details)

v3.10.0.1
Revolving Credit Facility (Details) - Revolving credit facility - Bank of America Credit Agreement - USD ($)
Jul. 11, 2017
Sep. 30, 2018
Dec. 31, 2017
Long-term debt      
Maximum borrowing capacity $ 25,000,000.0    
Annual commitment fee 0.20%    
Long-term line of credit   $ 1,800,000  
LIBOR      
Long-term debt      
Margin on variable rate 1.25%    
Effective interest rate   3.49% 2.82%