Shareholders' Equity	9 Months Ended
Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Share Awards: On March 29, 2018, in accordance with our Trustee compensation arrangements, and in connection with the election of one of our Managing Trustees, we granted 3,000 of our common shares, valued at $15.66 per share, the closing price of our common shares on Nasdaq on that day, to the Managing Trustee who was elected as a Managing Trustee on that day. On May 22, 2018, in accordance with our Trustee compensation arrangements, we granted 3,000 of our common shares, valued at $16.56 per share, the closing price of our common shares on Nasdaq on that day, to each of our five Trustees as part of their annual compensation. On September 13, 2018, we granted an aggregate of 105,800 of our common shares, valued at $19.11 per share, the closing price of our common shares on Nasdaq on that day, to our officers and certain other employees of RMR LLC under our equity compensation plan. Share Purchases: On January 1, 2018, we purchased 4,628 of our common shares, valued at $19.15 per share, the closing price of our common shares on Nasdaq on December 29, 2017, from a former employee of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. On September 24, 2018, we purchased an aggregate of 18,121 of our common shares, valued at $17.56 per share, the closing price of our common shares on Nasdaq on that day, from certain of our officers and other employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. On October 2, 2018, we purchased 250 of our common shares, valued at $17.05 per share, the closing price of our common shares on Nasdaq on that day, from a former employee of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. Distributions: On February 22, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,674, that was declared on January 19, 2018 and was payable to shareholders of record on January 29, 2018. On May 17, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,676, that was declared on April 19, 2018 and was payable to shareholders of record on April 30, 2018. On August 16, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,681, that was declared on July 19, 2018 and was payable to shareholders of record on July 30, 2018. On October 18, 2018, we declared a regular quarterly distribution payable to common shareholders of record on October 29, 2018, of $0.39 per share, or approximately $92,715. We expect to pay this distribution on or about November 15, 2018.

Shareholders’ Equity

Share Awards:

On March 29, 2018, in accordance with our Trustee compensation arrangements, and in connection with the election of one of our Managing Trustees, we granted 3,000 of our common shares, valued at $15.66 per share, the closing price of our common shares on Nasdaq on that day, to the Managing Trustee who was elected as a Managing Trustee on that day.

On May 22, 2018, in accordance with our Trustee compensation arrangements, we granted 3,000 of our common shares, valued at $16.56 per share, the closing price of our common shares on Nasdaq on that day, to each of our five Trustees as part of their annual compensation.

On September 13, 2018, we granted an aggregate of 105,800 of our common shares, valued at $19.11 per share, the closing price of our common shares on Nasdaq on that day, to our officers and certain other employees of RMR LLC under our equity compensation plan.

Share Purchases:

On January 1, 2018, we purchased 4,628 of our common shares, valued at $19.15 per share, the closing price of our common shares on Nasdaq on December 29, 2017, from a former employee of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares.

On September 24, 2018, we purchased an aggregate of 18,121 of our common shares, valued at $17.56 per share, the closing price of our common shares on Nasdaq on that day, from certain of our officers and other employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares.

On October 2, 2018, we purchased 250 of our common shares, valued at $17.05 per share, the closing price of our common shares on Nasdaq on that day, from a former employee of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares.

Distributions:

On February 22, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,674, that was declared on January 19, 2018 and was payable to shareholders of record on January 29, 2018. On May 17, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,676, that was declared on April 19, 2018 and was payable to shareholders of record on April 30, 2018. On August 16, 2018, we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,681, that was declared on July 19, 2018 and was payable to shareholders of record on July 30, 2018. On October 18, 2018, we declared a regular quarterly distribution payable to common shareholders of record on October 29, 2018, of $0.39 per share, or approximately $92,715. We expect to pay this distribution on or about November 15, 2018.