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GOODWILL AND INTANGIBLE ASSETS - Rollforward (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Changes in the carrying amount of goodwill, by operating segment |  |
Balance at the beginning of the period | $ 63,970 | $ 62,873
Acquisitions | 0 | 1,097
Balance at the end of the period | 63,970 | 63,970
U.S. Telecom |  |
Changes in the carrying amount of goodwill, by operating segment |  |
Balance at the beginning of the period | 35,268 | 35,268
Acquisitions | 0 | 0
Balance at the end of the period | 35,268 | 35,268
International Telecom |  |
Changes in the carrying amount of goodwill, by operating segment |  |
Balance at the beginning of the period | 25,423 | 24,326
Acquisitions | 0 | 1,097
Balance at the end of the period | 25,423 | 25,423
Renewable Energy |  |
Changes in the carrying amount of goodwill, by operating segment |  |
Balance at the beginning of the period | 3,279 | 3,279
Acquisitions | 0 | 0
Balance at the end of the period | $ 3,279 | $ 3,279

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Details
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- Details
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