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Real Estate Dispositions, Held for Sale, and Impairment Charges - Components of Income from Real Estate and Related Assets Held for Sale (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating expense | $ 13,733 | $ 15,172 | $ 13,433 | $ 13,257 | $ 12,970 | $ 13,643 | $ 12,595 | $ 11,757 | $ 55,595 | $ 50,965 | $ 57,406
Real Estate Held for Sale [Member] |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating revenue |  |  |  |  |  |  |  |  | 1,214 | 1,227 | 1,205
Operating expense |  |  |  |  |  |  |  |  | 974 | 348 | 327
Other expense |  |  |  |  |  |  |  |  | (397) | (547) | (555)
Income (loss) from real estate and related assets sold |  |  |  |  |  |  |  |  | $ (157) | $ 332 | $ 323

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- Definition Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts. + 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=26872669&loc=d3e20235-122688 + Details
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