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Basis of Presentation (Details) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 USD ($) building property | Dec. 31, 2018 USD ($)
Basis Of Presentation [Line Items] |  |
Variable interest entity, consolidated, carrying amount, assets | $ 1,050,254 | $ 1,061,593
Variable interest entity, consolidated, carrying amount, liabilities | $ (711,792) | $ (714,226)
Joint Venture |  |
Basis Of Presentation [Line Items] |  |
Noncontrolling interest, ownership percentage by parent | 45.00% |
Ownership percentage | 55.00% |
Massachusetts | MOBs | Joint Venture |  |
Basis Of Presentation [Line Items] |  |
Number of properties included in joint venture agreement | property | 1 |
Number of buildings included in joint venture agreement | building | 2 |

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