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Real Estate Dispositions, Held for Sale and Impairment Charges - Additional Information (Detail) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 USD ($) property | Sep. 30, 2017 USD ($) | Sep. 30, 2018 USD ($) property | Sep. 30, 2017 USD ($) property | Dec. 31, 2017 property
Real Estate Properties [Line Items] |  |  |  |  |
Number of properties sold |  |  | 2 |  |
Number of real estate properties, held for sale | 1 |  | 1 |  |
Number of impaired assets, held and used | 0 |  | 0 |  |
Impairment charge | $ | $ 0 | $ 0 | $ 0 | $ 3,999,000 |
Number of impaired assets sold, held for sale |  |  |  |  | 2
Arlington, Texas and Tewksbury, Massachusetts |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |
Number of real estate properties, held for sale |  |  |  |  | 2
Disposed of by sale |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |
Number of properties sold |  |  | 2 |  |
Held for sale |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |
Number of impaired assets |  |  |  | 2 |

X
- Definition Number of real estate properties held for sale. + References No definition available. + Details
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- Definition Number of Impaired Assets, Held and Used + References No definition available. + Details
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- Definition Number of Impaired Assets Sold, Held for Sale + References No definition available. + Details
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- Definition Number of Non-Core Properties Sold + References No definition available. + Details
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- Definition Number of impaired Assets + References No definition available. + Details
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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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- Details
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