Quarterly report pursuant to Section 13 or 15(d)

Debt and Interest Rate Swap (Details)

v3.20.2
Debt and Interest Rate Swap (Details) - USD ($)
3 Months Ended 6 Months Ended 29 Months Ended 35 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Mar. 31, 2020
Mar. 31, 2020
Dec. 31, 2019
Nov. 03, 2017
May 12, 2017
Debt Instrument [Line Items]                  
Long-term Debt, Gross $ 212,000,000.0   $ 212,000,000.0       $ 212,000,000.0    
Debt Instrument, Unamortized Discount                 $ (2,100,000)
Long-term debt 207,486,000   207,486,000       $ 206,909,000    
Line of Credit Facility, Incremental Borrowing Capacity $ 160,000,000.0   $ 160,000,000.0            
Debt Instrument, Frequency of Periodic Payment     quarterly installments            
Debt Instrument, Quarterly Amortization Rate 0.25%   0.25%            
Debt Instrument, Call Feature     1.0% soft call premium            
Repayments of Debt           $ 213,000,000.0      
Document Period End Date     Jun. 30, 2020            
Debt Instrument, Interest Rate, Effective Percentage 4.40%   4.40%       4.90%   4.60%
Long-term Debt, Fair Value $ 209,100,000   $ 209,100,000       $ 214,600,000   $ 398,500,000
Debt Issuance Costs, Gross                 6,000,000.0
Amortization of debt issuance costs and accretion of discount on debt and leases $ 300,000 $ 300,000 $ 600,000 $ 600,000          
Derivative, Fixed Interest Rate 4.25%   4.25%         1.74685%  
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss) $ 100,000 (800,000) $ (48,000) (1,405,000)          
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax 116,000 $ (623,000) (37,000) $ (1,111,000) $ 1,600,000        
Derivative Liability 85,000   $ 85,000       37,000    
Base Rate [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Interest Rate Terms     a base rate            
Debt Instrument, Basis Spread on Variable Rate     1.50%            
Fed Funds Effective Rate Overnight Index Swap Rate [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Interest Rate Terms     the federal funds rate, plus 0.50%            
Prime Rate [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Interest Rate Terms     prime rate            
One, Two, Or Three Month London Interbank Offered Rate (LIBOR) [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Interest Rate Terms     an adjusted LIBOR rate determined on the basis of a one- three- or six-month interest period, plus 1.0%            
London Interbank Offered Rate (LIBOR) Subject to Floor [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Interest Rate Terms     adjusted LIBOR rate, subject to a floor of 0.75%            
Debt Instrument, Basis Spread on Variable Rate     2.50%            
London Interbank Offered Rate (LIBOR) [Member]                  
Debt Instrument [Line Items]                  
Debt Instrument, Basis Spread on Variable Rate     2.50%            
Medium-term Notes [Member]                  
Debt Instrument [Line Items]                  
Long-term Debt, Gross 212,000,000   $ 212,000,000       212,000,000   $ 425,000,000.0
Debt Instrument, Unamortized Discount (1,177,000)   (1,177,000)       (1,328,000)    
Debt Issuance Costs, Net (3,337,000)   (3,337,000)       (3,763,000)    
Long-term Debt 207,486,000   207,486,000       206,909,000    
Long-term Debt, Current Maturities 0   0       0    
Long-term debt 207,486,000   207,486,000       206,909,000    
Fair Value, Inputs, Level 2 [Member]                  
Debt Instrument [Line Items]                  
Derivative Liability 85,000   85,000       37,000    
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Derivative Financial Instruments, Assets [Member]                  
Debt Instrument [Line Items]                  
Derivative Liability $ 100,000   $ 100,000       $ 40,000.00