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Real Estate Dispositions, Held for Sale, and Impairment Charges - Components of Operating Income from Real Estate and Related Assets Disposed (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 Asset Disposal [Member] |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating revenue |  |  |  |  |  |  |  |  | 647 | 1,045 | 1,272
Operating expense |  |  |  |  |  |  |  |  | 469 | 1,071 | 564
Other income (expense) |  |  |  |  |  |  |  |  | 47 | (353) | (406)
Income (loss) from real estate and related assets sold |  |  |  |  |  |  |  |  | $ 225 | $ (379) | $ 302

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- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. + References No definition available. + Details
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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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