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Summary of Significant Accounting Policies - Construction-in-Progress (Textual) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Construction in Progress [Line Items] |  |  |
Internal direct construction costs capitalized related to development of properties and land holdings | $ 6,964 | $ 6,063 | $ 6,717
Development [Member] |  |  |
Construction in Progress [Line Items] |  |  |
Internal direct construction costs capitalized related to development of properties and land holdings | 3,185 | 4,390 | 3,182
Capitalized interest | $ 3,600 | $ 3,100 | $ 10,900

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- Definition [Line Items] for Schedule of Capitalized Salaries Including Bonuses and Benefits [Table] + References No definition available. + Details
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- Definition Amount of interest capitalized during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 + Details
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