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Business - Additional Information (Details) | Jun. 30, 2018 State Property ApartmentUnit | Apr. 02, 2018 ApartmentUnit | Feb. 01, 2018 ApartmentUnit
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Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |
Number of states in which entity operates | State | 10 |  |
Properties | Property | 304 |  |
Apartment units | 78,645 |  |
Master-Leased Properties – Consolidated |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |
Properties | Property | 1 |  |
Apartment units | 162 |  |
Master-Leased Properties – Consolidated | Boston |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |
Number of self managed apartments |  |  | 94
Master-Leased Properties – Consolidated | Los Angeles |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |
Number of self managed apartments |  | 597 |
ERPOP [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |
Noncontrolling interest, ownership percentage by parent | 96.30% |  |

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- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
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- Details
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