Quarterly report pursuant to Section 13 or 15(d)

Senior Credit Facility (Details)

v3.7.0.1
Senior Credit Facility (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2017
Mar. 31, 2015
Jun. 30, 2017
Jun. 30, 2016
Feb. 04, 2015
Debt Instrument [Line Items]          
Line of Credit Facility Term, In Years         5
Credit facility amount         $ 275,000
Base reference rate of credit facilities     LIBOR    
Interest rate spread above LIBOR as of reporting period (in hundredths)     1.00%    
Proceeds from senior credit facility     $ 35,000 $ 0  
Letters of Credit Outstanding, Amount $ 7,514   7,514    
Available borrowing capacity 121,986   $ 121,986    
Letter of Credit [Member]          
Debt Instrument [Line Items]          
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases         25,000
Swing line loan [Member]          
Debt Instrument [Line Items]          
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases         15,000
Revolving Credit Facility [Member]          
Debt Instrument [Line Items]          
Credit facility amount         $ 150,000
Debt Instrument, Basis Spread on Variable Rate, Minimum         0.30%
Debt Instrument, Basis Spread on Variable Rate, Maximum         0.80%
Proceeds from senior credit facility $ 20,500        
Line of Credit Facility, Interest Rate at Period End 2.50%   2.50%    
Federal funds [Member]          
Debt Instrument [Line Items]          
Interest rate spread above LIBOR as of reporting period (in hundredths)     0.50%    
Term loan [Member]          
Debt Instrument [Line Items]          
Credit facility amount         $ 125,000
Debt Instrument, Basis Spread on Variable Rate, Minimum         0.10%
Debt Instrument, Basis Spread on Variable Rate, Maximum         0.60%
Proceeds from term loan   $ 125,000      
Term Loan, Quarterly Payment Percentage     11.10%