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Business and Property Management Agreements with RMR LLC (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2020 USD ($) employee management_agreement | Sep. 30, 2019 USD ($) | Sep. 30, 2020 USD ($) employee management_agreement | Sep. 30, 2019 USD ($) | Dec. 31, 2020
Related person transactions |  |  |  |  |
Number of employees | employee | 0 |  | 0 |  |
Property management and construction supervision fees | $ 3,477,000 | $ 3,289,000 | $ 10,076,000 | $ 9,844,000 |
Property management and construction supervision fees paid | 3,571,000 | 3,419,000 | 10,433,000 | 10,145,000 |
RMR LLC |  |  |  |  |
Related person transactions |  |  |  |  |
Business management fees incurred | 5,004,000 | 6,616,000 | 15,614,000 | 20,917,000 |
Related party transaction business management fees related to subsidiary level management | 725,000 | 725,000 | 2,175,000 | 2,175,000 |
Related party transaction business management agreement, annual incentive fee estimate included in management fees | $ 0 | $ 0 | $ 0 | $ 0 |
Senior Living Communities | RMR Inc |  |  |  |  |
Related person transactions |  |  |  |  |
Number of management agreements | management_agreement | 2 |  | 2 |  |
Subsequent Event | Scenario, Forecast | RMR LLC |  |  |  |  |
Related person transactions |  |  |  |  |
Period of actual amount of incentive fees |  |  |  |  | 3 years

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