Annual report pursuant to Section 13 and 15(d)

Debt (Details)

v3.6.0.2
Debt (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Long-term Debt, Fiscal Year Maturity [Abstract]    
Deferred financing costs $ 1,700,000 $ 2,200,000
Amended and Restated    
Debt Instrument [Line Items]    
Financing costs $ 2,700,000  
Amortization period of debt issuance costs 5 years  
Long-term Debt, Fiscal Year Maturity [Abstract]    
Debt outstanding $ 216,300,000 234,700,000
Revolving loans potential increment in maximum borrowing capacity $ 75,000,000  
Duration of interest rate cash flow hedge 3 years  
Derivative, notional amount $ 100,000,000  
Effective interest rate 3.27%  
Interest expense, net $ 7,800,000 7,300,000
Amended and Restated | LIBOR    
Long-term Debt, Fiscal Year Maturity [Abstract]    
Base margin 2.25%  
Amended and Restated | Base Rate    
Long-term Debt, Fiscal Year Maturity [Abstract]    
Base margin 1.00%  
Term Loan    
Long-term Debt, Fiscal Year Maturity [Abstract]    
2017 $ 21,600,000  
2018 28,100,000  
2019 30,000,000  
2020 36,200,000  
Debt outstanding 115,900,000  
Revolving Loans    
Long-term Debt, Fiscal Year Maturity [Abstract]    
Revolving loans maximum borrowing capacity 150,000,000  
Revolving loans amount outstanding 100,400,000 101,000,000
Letters of credit outstanding $ 0 $ 0
Minimum | Amended and Restated    
Long-term Debt, Fiscal Year Maturity [Abstract]    
Stated interest rate 2.96%  
Maximum | Amended and Restated    
Long-term Debt, Fiscal Year Maturity [Abstract]    
Stated interest rate 4.75%