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COMMITMENTS AND CONTINGENCIES (Details) - 62 Boylston Street in Boston, MA | 12 Months Ended |
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Dec. 31, 2017 USD ($) | Nov. 19, 2016 item
Loss Contingencies [Line Items] |  |
Number of apartments damaged | item |  | 24
Proceeds from Insurance | $ | $ 329,000 |

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- Definition Amount of cash inflow for proceeds from settlement of insurance claim, classified as operating activities. Excludes insurance settlement classified as investing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 21B -URI http://asc.fasb.org/extlink&oid=98514028&loc=SL94080549-108585 + Details
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