Related Person Transactions	3 Months Ended
Mar. 31, 2019
Related Party Transactions [Abstract]
Related Person Transactions	Note 10. Related Person Transactions We have relationships and historical and continuing transactions with TA, Sonesta, RMR LLC, The RMR Group Inc., or RMR Inc., AIC 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. TA. TA is our largest tenant and property operator, leasing 31% of our gross carrying value of real estate properties as of March 31, 2019. We lease all of our travel centers to TA under the TA leases. We are also TA’s largest shareholder; as of March 31, 2019, we owned 3,420,000 common shares of TA, representing approximately 8.5% of TA’s outstanding common shares. RMR LLC provides management services to both us and TA, and Adam D. Portnoy, one of our Managing Trustees, also serves as a managing director of TA and, as of March 31, 2019, beneficially owned through RMR LLC 1,492,691 common shares of TA, representing approximately 3.7% of TA's outstanding common shares. See Note 8 for further information regarding our relationships, agreements and transactions with TA and Note 13 for further information regarding our investment in TA. Sonesta. Sonesta is a private company owned in part by Adam Portnoy, one of our Managing Trustees. Both our Managing Trustees and our Secretary are directors of Sonesta. As of March 31, 2019, Sonesta managed 51 of our hotels pursuant to management and pooling agreements. See Note 8 for further information regarding our relationships, agreements and transactions with Sonesta. Our Manager, RMR LLC. We have two agreements with RMR LLC to provide management services to us. See Note 9 for further information regarding our management agreements with RMR LLC. RMR Inc. RMR LLC is a majority owned subsidiary of RMR Inc. One of our Managing Trustees, Adam Portnoy, is the sole trustee of ABP Trust, is the controlling shareholder of RMR Inc., is a managing director and the president and chief executive officer of RMR Inc. and an officer and employee of RMR LLC. John G. Murray, our other Managing Trustee and our President and Chief Executive Officer, and each of our other officers is also an officer and employee of RMR LLC, including Ethan S. Bornstein, the brother-in-law of Adam Portnoy. As of March 31, 2019, we owned 2,503,777 shares of class A common stock of RMR Inc. See Note 13 for further information regarding our investment in RMR Inc. AIC. We, ABP Trust, TA and four other companies to which RMR LLC provides management services currently own AIC, an Indiana insurance company, in equal amounts. We and the other AIC shareholders participate in a combined property insurance program arranged and reinsured in part by AIC. As of March 31, 2019 and December 31, 2018, our investment in AIC had a carrying value of $9,109 and $8,639, respectively. These amounts are included in other assets in our condensed consolidated balance sheets. We recognized income of $404 and $44 for the three months ended March 31, 2019 and 2018, respectively, related to our investment in AIC, which amounts are presented as equity in earnings of an investee in our condensed consolidated statements of comprehensive income. Our other comprehensive income (loss) includes our proportionate part of unrealized gains and (losses) on securities that are owned by AIC related to our investment in AIC. For further information about these and certain other such relationships and certain other related person transactions, refer to our 2018 Annual Report.

Note 10. Related Person Transactions

We have relationships and historical and continuing transactions with TA, Sonesta, RMR LLC, The RMR Group Inc., or RMR Inc., AIC 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.

TA. TA is our largest tenant and property operator, leasing 31% of our gross carrying value of real estate properties as of March 31, 2019. We lease all of our travel centers to TA under the TA leases. We are also TA’s largest shareholder; as of March 31, 2019, we owned 3,420,000 common shares of TA, representing approximately 8.5% of TA’s outstanding common shares. RMR LLC provides management services to both us and TA, and Adam D. Portnoy, one of our Managing Trustees, also serves as a managing director of TA and, as of March 31, 2019, beneficially owned through RMR LLC 1,492,691 common shares of TA, representing approximately 3.7% of TA's outstanding common shares. See Note 8 for further information regarding our relationships, agreements and transactions with TA and Note 13 for further information regarding our investment in TA.

Sonesta. Sonesta is a private company owned in part by Adam Portnoy, one of our Managing Trustees. Both our Managing Trustees and our Secretary are directors of Sonesta. As of March 31, 2019, Sonesta managed 51 of our hotels pursuant to management and pooling agreements. See Note 8 for further information regarding our relationships, agreements and transactions with Sonesta.

Our Manager, RMR LLC. We have two agreements with RMR LLC to provide management services to us. See Note 9 for further information regarding our management agreements with RMR LLC.

RMR Inc. RMR LLC is a majority owned subsidiary of RMR Inc. One of our Managing Trustees, Adam Portnoy, is the sole trustee of ABP Trust, is the controlling shareholder of RMR Inc., is a managing director and the president and chief executive officer of RMR Inc. and an officer and employee of RMR LLC. John G. Murray, our other Managing Trustee and our President and Chief Executive Officer, and each of our other officers is also an officer and employee of RMR LLC, including Ethan S. Bornstein, the brother-in-law of Adam Portnoy. As of March 31, 2019, we owned 2,503,777 shares of class A common stock of RMR Inc. See Note 13 for further information regarding our investment in RMR Inc.

AIC. We, ABP Trust, TA and four other companies to which RMR LLC provides management services currently own AIC, an Indiana insurance company, in equal amounts. We and the other AIC shareholders participate in a combined property insurance program arranged and reinsured in part by AIC.

As of March 31, 2019 and December 31, 2018, our investment in AIC had a carrying value of $9,109 and $8,639, respectively. These amounts are included in other assets in our condensed consolidated balance sheets. We recognized income of $404 and $44 for the three months ended March 31, 2019 and 2018, respectively, related to our investment in AIC, which amounts are presented as equity in earnings of an investee in our condensed consolidated statements of comprehensive income. Our other comprehensive income (loss) includes our proportionate part of unrealized gains and (losses) on securities that are owned by AIC related to our investment in AIC.

For further information about these and certain other such relationships and certain other related person transactions, refer to our 2018 Annual Report.