Acquisition of Gordon Trucking, Inc. Potential Earn Out Schedule (Details) (USD $)	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Acquisition of Gordon Trucking [Abstract]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 8,000,000	$ 6,000,000	$ 6,000,000	$ 20,000,000
Earn Out Agreement				$ 13,600,000

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant