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Equity - Narrative (Details) - USD ($) $ in Thousands | 1 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Mar. 31, 2017 | Jun. 30, 2019 | Dec. 31, 2018
Equity |  |  |
Common stock sold (in shares) |  | 0 | 0
Sale of Stock, Consideration Received if Additional Shares are Issued | $ 60,000 |  |
Commission fee percentage on gross proceeds from sale of ATM shares | 3.00% |  |

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