Annual report pursuant to Section 13 and 15(d)

Operating Leases (Details)

v3.6.0.2
Operating Leases (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
USD ($)
Years
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Operating Leased Assets [Line Items]      
Operating lease renewal option, minimum (in years) | Years 1    
Operating lease renewal option, maximum (in years) | Years 10    
Operating lease original term, for tractors, trucks and trailers, minimum (in years) 3 years    
Operating lease original term, for tractors, trucks and trailers, maximum (in years) 5 years    
Sublease rental income $ 1,517 $ 1,611 $ 980
Expected future sublease rental income 1,011    
Operating Leases, Future Minimum Payments Due [Abstract]      
2017 36,106    
2018 27,320    
2019 19,449    
2020 12,604    
2021 5,454    
Thereafter 2,990    
Total $ 103,923