Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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Period Type:	duration

ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION (ASC Topic 606) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
ASC Topic 606
Retained earnings	$ 450,267			$ 438,379
Revenues	700,001	$ 651,088
Difference between Revenue Guidance in Effect before and after Topic 606 \| ASC Topic 606, Revenue from Contracts with Customers
ASC Topic 606
Retained earnings			$ 400
Revenues	(300)
Purchased transportation	$ (300)