Related Person Transactions	9 Months Ended
Related Person Transactions	Sep. 30, 2020
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions We have relationships and historical and continuing transactions with RMR LLC, RMR Inc., Five Star and others related to them, including other companies to which RMR LLC or its subsidiaries provide management services and some of which have trustees, directors or officers who are also our Trustees or officers. RMR Inc. is the managing member of RMR LLC. The Chair of our Board and one of our Managing Trustees, Adam Portnoy, is the sole trustee, an officer and the controlling shareholder of ABP Trust, which is the controlling shareholder of RMR Inc., a managing director and the president and chief executive officer of RMR Inc., an officer and employee of RMR LLC and the chair of the board of directors and a managing director of Five Star. Jennifer Clark, our other Managing Trustee and our Secretary, also serves as a managing director and the executive vice president, general counsel and secretary of RMR Inc., an officer and employee of RMR LLC, an officer of ABP Trust and a managing director and the secretary of Five Star, and each of our officers is also an officer and employee of RMR LLC. Some of our Independent Trustees also serve as independent trustees or independent directors of other public companies to which RMR LLC or its subsidiaries provide management services. Adam Portnoy serves as the chair of the boards of trustees or boards of directors of several of these public companies and as a managing director or managing trustee of these companies. Other officers of RMR LLC, including Ms. Clark and certain of our other officers, serve as managing trustees, managing directors or officers of certain of these companies. Five Star. We are currently Five Star's largest stockholder. As of September 30, 2020, we owned 10,691,658 Five Star common shares, or approximately 33.9% of Five Star's outstanding common shares. Five Star manages for us most of the senior living communities we own. RMR LLC provides management services to both us and Five Star. Five Star participates in our property insurance program for the senior living communities Five Star owns and leases. The premiums Five Star pays for this coverage are allocated pursuant to a formula based on the profiles of the properties included in the program. Five Star's program cost for the policy year ending June 30, 2021 is $500. See Note 10 for further information regarding our relationships, agreements and transactions with Five Star and Note 6 for further information regarding our investment in Five Star. As of September 30, 2020, ABP Acquisition LLC, a subsidiary of ABP Trust, the controlling shareholder of RMR Inc., together with ABP Trust, owned approximately 6.4% of Five Star's outstanding common shares. RMR LLC provides management services to both us and Five Star and Adam Portnoy is the chair of the board of directors and a managing director of Five Star. Jennifer Clark is a managing director and the secretary of Five Star. Five Star's president and chief executive officer and executive vice president, chief financial officer and treasurer are officers and employees of RMR LLC. Our Manager, RMR LLC. We have two agreements with RMR LLC to provide management services to us. RMR LLC also leases office space from us pursuant to a lease agreement that is terminable on 30 days' notice, subject to certain conditions. See Note 11 for further information regarding our management agreements with RMR LLC. See Note 8 for information relating to the annual share awards we made in September 2020 to our officers and certain other employees of RMR LLC and common shares we purchased from our officers and certain current and former officers and employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares to them. We include amounts recognized as expense for share awards to RMR LLC employees in general and administrative expenses in our condensed consolidated statements of comprehensive income (loss). AIC. Until its dissolution in February 2020, we, ABP Trust, Five Star and four other companies to which RMR LLC provides management services owned Affiliates Insurance Company, or AIC, an Indiana insurance company, in equal amounts. Certain of our Trustees and certain directors or trustees of the other AIC shareholders served on the board of directors of AIC until its dissolution. We and the other AIC shareholders historically participated in a combined property insurance program arranged and insured or reinsured in part by AIC. The policies under that program expired on June 30, 2019, and we and the other AIC shareholders elected not to renew the AIC property insurance program; we have instead purchased standalone property insurance coverage with unrelated third party insurance providers. As of each of September 30, 2020 and December 31, 2019, our investment in AIC had a carrying value of $11 and $298, respectively. These amounts are included in other assets, net in our condensed consolidated balance sheets. In June 2020, we received an additional liquidating distribution of approximately $287 from AIC in connection with its dissolution. We did not recognize any income related to our investment in AIC for the three and nine months ended September 30, 2020 and recognized $83 and $617 related to our investment in AIC for the three and nine months ended September 30, 2019, respectively. These amounts are presented as equity in earnings of an investee in our condensed consolidated statements of comprehensive income (loss). Our other comprehensive income (loss) included our proportionate share of unrealized gains (losses) on securities that were owned by AIC, related to our investment in AIC. For further information about these and other such relationships and certain other related person transactions, see our Annual Report.