v3.8.0.1

INTANGIBLE ASSETS (Tables) | 12 Months Ended
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Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract] |
Schedule of Finite-Lived Intangible Assets by Major Class [Table Text Block] | Intangible assets consisted of the following:
|  |  | December 31, 2017 |  | December 31, 2016
| Weighted-Average Amortization Period |  | Cost |  | Accumulated Amortization |  | Cost |  | Accumulated Amortization
| (Years) |  | (Thousands of Dollars)
Customer contracts and relationships | 18 |  | $ | 863,950 |  |  | $ | (81,136 | ) |  | $ | 166,950 |  |  | $ | (41,582 | )
Other | 47 |  | 2,359 |  |  | (694 | ) |  | 2,359 |  |  | (644 | )
Total |  |  | $ | 866,309 |  |  | $ | (81,830 | ) |  | $ | 169,309 |  |  | $ | (42,226 | )

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- Definition Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite life, by either major class or business segment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
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