Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Senior Secured Credit Facility - Revolver and Term Loan (Details)

v3.10.0.1
Long-Term Debt - Senior Secured Credit Facility - Revolver and Term Loan (Details)
Jun. 30, 2015
USD ($)
bank
Dec. 31, 2018
USD ($)
Jun. 30, 2018
USD ($)
Dec. 31, 2017
USD ($)
Jun. 01, 2017
USD ($)
May 31, 2017
USD ($)
Nov. 30, 2016
USD ($)
Line of Credit Facility [Line Items]              
Long-term debt value, carrying value   $ 253,873,000   $ 202,168,000      
Remaining borrowing capacity       72,234,000      
Revolving Credit Facility              
Line of Credit Facility [Line Items]              
Line of credit facility, number of banks | bank 2            
Additional borrowing capacity (up to) $ 25,000,000            
Current borrowing capacity $ 85,000,000            
Total Funded Debt to EBITDA covenant ratio, maximum     3.00     2.75  
Long-term debt value, carrying value     $ 136,000,000        
Amount outstanding   $ 1,696,000   27,580,000      
Commitment fee percentage 0.375%            
Debt interest rate   4.52%          
Periodic principal payment $ 1,500,000            
Maximum amount of Company's consolidated stockholders' equity eligible for investment in or loan to non-core subsidiaries 0.49            
Minimum debt service coverage ratio 1.5            
Revolving Credit Facility | As of the end of each fiscal quarter ending September 30, 2016, December 31, 2016, March 31, 2017 and June 30, 2017              
Line of Credit Facility [Line Items]              
Maximum EBITDA requirement 3            
Revolving Credit Facility | Federal Funds Effective Rate              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 0.50%            
Revolving Credit Facility | London Interbank Offered Rate (LIBOR)              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 1.50%            
Revolving Credit Facility | Minimum | Base Rate              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 0.50%            
Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR)              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 2.00%            
Revolving Credit Facility | Maximum              
Line of Credit Facility [Line Items]              
Current borrowing capacity $ 20,000,000            
Revolving Credit Facility | Maximum | Base Rate              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 0.25%            
Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR)              
Line of Credit Facility [Line Items]              
Basis spread on variable rate 1.75%            
Term loan              
Line of Credit Facility [Line Items]              
Additional borrowing capacity (up to)             $ 20,000,000
Current borrowing capacity     46,000,000   $ 75,000,000 $ 60,000,000 $ 30,000,000
Term loan | Notes payable to banks              
Line of Credit Facility [Line Items]              
Long-term debt value, carrying value   $ 41,500,000   $ 22,500,000      
Original principal amount $ 46,000,000            
Debt interest rate   4.72%          
Term loan | Revolving Credit Facility              
Line of Credit Facility [Line Items]              
Current borrowing capacity           25,000,000  
Line of Credit | Revolving Credit Facility              
Line of Credit Facility [Line Items]              
Current borrowing capacity     $ 85,000,000     $ 75,000,000  
Letter of Credit              
Line of Credit Facility [Line Items]              
Long-term debt value, carrying value   $ 11,070,000