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SIGNIFICANT ACCOUNTING POLICIES - Collectability of Lease Payments (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Collectability of Lease Payments |  |
Bad debt expense | $ 684,000 | $ 291,000

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- Definition Amount of expense (reversal of expense) for expected credit loss on accounts receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(5)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
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