Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.10.0.1
Debt (Details) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Jan. 31, 2018
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Debt Instrument [Line Items]            
Deferred financing costs   $ 2,200,000   $ 2,200,000   $ 1,100,000
Long-term Debt, Fiscal Year Maturity [Abstract]            
Debt outstanding   177,100,000   $ 177,100,000   173,700,000
LIBOR            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Base margin       2.00%    
Base Rate            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Base margin       0.75%    
Amended and Restated            
Debt Instrument [Line Items]            
Deferred financing costs   $ 1,700,000   $ 1,700,000    
Amortization period of debt issuance costs 5 years          
Long-term Debt, Fiscal Year Maturity [Abstract]            
Increase in maximum availability       $ 100,000,000    
Duration of interest rate cash flow hedge       3 years    
Effective interest rate   4.10%   4.10%    
Interest expense, net   $ 1,900,000 $ 1,800,000 $ 5,100,000 $ 5,600,000  
Amended and Restated | Minimum            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Interest rate range   3.25%   3.25%    
Amended and Restated | Maximum            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Interest rate range   6.00%   6.00%    
Amended and Restated | Swap            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Derivative notional amount   $ 50,000,000   $ 50,000,000   85,000,000
Term Loan Facility            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Term loan payments 2018   2,500,000   2,500,000    
Term loan payments 2019   10,000,000   10,000,000    
Term loan payments 2020   11,900,000   11,900,000    
Term loan payments 2021   14,400,000   14,400,000    
Term loan payments 2022   15,000,000   15,000,000    
Term loan payments 2023   39,500,000   39,500,000    
Borrowings outstanding   93,300,000   93,300,000    
Revolving Loan Facility            
Long-term Debt, Fiscal Year Maturity [Abstract]            
Revolving loans maximum borrowing capacity   300,000,000   300,000,000    
Revolving loans amount outstanding   83,800,000   83,800,000   79,300,000
Letters of credit outstanding   $ 57,000   $ 57,000   $ 0