Acquisition of Gordon Trucking, Inc. Allocation of Purchase Price (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Cash Acquired from Acquisition	$ (20,000)
Cash paid (before netting $20 million cash acquired)	$ 115,900
Stock Issued During Period, Shares, Acquisitions	2,860,000
Earn Out Agreement			$ 13,600
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
Gordon Trucking Company, Inc [Member]
Business Acquisition [Line Items]
Total fair value of consideration transferred (before netting $20 million cash acquired), excluding debt assumed	$ 172,000