Annual report pursuant to Section 13 and 15(d)

Debt (Details)

v3.20.1
Debt (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]      
Long-term debt $ 272,800,000 $ 162,734,000  
Less debt issuance costs (2,789,000) (2,135,000)  
Total long-term debt 270,011,000 160,599,000  
Less current portion (16,883,000) (9,466,000)  
Long-term debt, less current portion 253,128,000 151,133,000  
Long-term Debt, Fiscal Year Maturity [Abstract]      
Total long-term debt 270,011,000 160,599,000  
Amended and Restated      
Long-term Debt, Fiscal Year Maturity [Abstract]      
Revolving loans, potential increment in maximum borrowing capacity $ 100,000,000    
Effective interest rate 4.77%    
Interest expense, net $ 13,300,000 6,900,000 $ 7,200,000
Amended and Restated | LIBOR      
Long-term Debt, Fiscal Year Maturity [Abstract]      
Base margin 2.50%    
Amended and Restated | Base Rate      
Long-term Debt, Fiscal Year Maturity [Abstract]      
Base margin 1.25%    
Term Loan      
Debt Instrument [Line Items]      
Long-term debt $ 120,800,000 80,800,000  
Total long-term debt 120,800,000    
Long-term Debt, Fiscal Year Maturity [Abstract]      
2020 17,813,000    
2021 21,562,000    
2022 22,500,000    
2023 58,925,000    
Total long-term debt 120,800,000    
Revolving Loans      
Debt Instrument [Line Items]      
Long-term debt 152,000,000 81,934,000  
Long-term Debt, Fiscal Year Maturity [Abstract]      
Revolving loans maximum borrowing capacity 350,000,000    
Letters of credit outstanding $ 54,000 $ 57,000  
Minimum | Amended and Restated      
Long-term Debt, Fiscal Year Maturity [Abstract]      
Stated interest rate 4.21%    
Maximum | Amended and Restated      
Long-term Debt, Fiscal Year Maturity [Abstract]      
Stated interest rate 6.00%