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ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION (Organization) (Details) - segment | 6 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2018
Organization and description of business |  |
Number of reportable operating segments |  | 3
Asset-Based |  |
Organization and description of business |  |
Percentage of the Company's revenues, before other revenues and intercompany eliminations, represented by the Asset-Based segment |  | 69.00%
Vacation accrual period | 5 days |
Estimated increase in compounded annual contractual wage and benefit contribution rates (as a percent) |  | 2.00%
Asset-Based | Unionized employees concentration risk | Number of employees |  |
Organization and description of business |  |
Percentage of Asset-Based segment employees covered under collective bargaining agreement with the IBT |  | 83.00%

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- Definition Period of vacation accrual restored under the collective bargaining agreement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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