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Properties, Net (Details 2) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Properties |  |
Projects in development or held for future development | $ 403,361 | $ 403,494
Projects in development or held for future development [Member] | Land [Member] |  |
Properties |  |
Projects in development or held for future development | 207,760 | 240,825
Projects in development or held for future development [Member] | Development in progress, excluding land [Member] |  |
Properties |  |
Projects in development or held for future development | $ 195,601 | $ 162,669

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- Definition The current amount of expenditures for a real estate project that has not yet been completed. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.10) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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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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Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
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- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
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Balance Type: |
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