Prepaid Tires, Property, Equipment and Depreciation (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Amortization Period of Tires	2 years
Increase (Decrease) in Restricted Cash and Investments	$ 6,313	$ 1,803	$ 200
Tractors [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Salvage Value	15
Trailers [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Salvage Value	$ 4