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Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Minimum rental payments due |  | $ 91,338
Ground Leases |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Minimum rental payments due |  | $ 90,400
Accounting Standards Update 2014-09 |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Effect of change on net income | $ 18,000 |

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