Acquisition of Gordon Trucking, Inc. Potential Earn Out Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Nov. 11, 2013
Acquisition of Gordon Trucking [Abstract]
Potential Earn Out, 2014	$ 6,000
Potential Earn Out, 2015	6,000
Potential Earn Out, 2016 & 2017	8,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	20,000			$ 20,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	(1,764)	$ 0	$ 0
Earn Out Agreement		13,600
business combination contingent consideration fair value non-current	$ 12,200	$ 11,300