Annual report pursuant to Section 13 and 15(d)

Debt and Capital Lease Obligations (Details)

v3.10.0.1
Debt and Capital Lease Obligations (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Sep. 29, 2017
Line of Credit Facility [Line Items]    
Credit facility term (in years)   5
Senior credit facility amount   $ 250,000
Additional borrowing capacity of credit facility   $ 100,000
Base reference rate of credit facilities LIBOR  
Debt Instrument, Basis Spread on Variable Rate 1.00%  
Utilized for outstanding letters of credit $ 10,650  
Available borrowing capacity 91,850  
Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Basis spread on variable rate minimum (in hundredths)   0.30%
Basis spread on variable rate maximum (in hundredths)   0.80%
Proceeds from Lines of Credit 47,500  
Available borrowing capacity $ 150,000  
Line of Credit Facility, Interest Rate at Period End 4.10%  
Letter of Credit [Member]    
Line of Credit Facility [Line Items]    
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases   $ 30,000
Swing line loan [Member]    
Line of Credit Facility [Line Items]    
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases   $ 30,000
Federal funds [Member]    
Line of Credit Facility [Line Items]    
Debt Instrument, Basis Spread on Variable Rate 0.50%