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SUPPLEMENTAL FINANCIAL INFORMATION - Schedules of Components of Revenues (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Supplemental Financial Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue | $ 3,043 | $ 451 | $ 26,973 | $ 1,254 | $ 3,908 | $ 5,499 | $ 17,883 | $ 3,756 | $ 31,721 | $ 31,046 | $ 54,552
Other | Geographic Concentration Risk | Sales Revenue, Net |  |  |  |  |  |  |  |  |  |  |
Supplemental Financial Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | $ 5,030 | $ 4,400 | $ 3,690

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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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