Related Person Transactions (Details)	3 Months Ended			3 Months Ended				0 Months Ended	3 Months Ended								1 Months Ended	3 Months Ended			0 Months Ended
	Mar. 31, 2013 USD ($) item	Mar. 31, 2012 USD ($)	Jan. 31, 2012 SNSTA USD ($)	Mar. 31, 2013 RMR USD ($) item agreement	Mar. 31, 2012 RMR USD ($)	Mar. 31, 2013 Travel Centers of America LLC USD ($) item	Dec. 31, 2012 Travel Centers of America LLC USD ($)	Apr. 15, 2013 Travel Centers of America LLC Travel centers Property	Mar. 31, 2013 Travel Centers of America LLC Travel centers USD ($) item Property	Mar. 31, 2012 Travel Centers of America LLC Travel centers USD ($)	Mar. 31, 2013 Travel Centers of America LLC Travel centers TA No. 1 USD ($) Property	Mar. 31, 2012 Travel Centers of America LLC Travel centers TA No. 1 USD ($)	Mar. 31, 2013 Travel Centers of America LLC Travel centers TA No. 2 USD ($) Property	Mar. 31, 2013 Travel Centers of America LLC Travel centers TA No. 2 Maximum item	Mar. 31, 2013 Sonesta Sonesta agreements USD ($)	Mar. 31, 2012 Sonesta Sonesta agreements USD ($)	Jun. 30, 2012 AIC USD ($)	Mar. 31, 2013 AIC USD ($) item	Mar. 31, 2012 AIC USD ($)	Dec. 31, 2012 AIC USD ($)	Feb. 27, 2013 NHH EUR (€) Property
Related Person Transactions
Number of employees	0
Number of agreements to provide management and administrative services				2
Number of properties included in management agreement				1
Number of Managing Trustees who are Chairmen, majority owners and employees of RMR				1
Business and property management agreement expenses				$ 9,922,000	$ 8,648,000										$ 1,895,000	$ 459,000
Percentage of ownership formerly held in subsidiary						100.00%
Number of common shares owned						2,540,000
Common shares of TA held by company as a percent of total TA shares outstanding						8.60%
Number of Managing Trustees who are Managing Directors						1
Number of management agreements or leases	11								2
Number of properties leased									185		145		40
Number of renewal options available														2
Term of renewal option													15 years
Percentage of non-fuel revenue over threshold amounts									3.00%
Percentage of fuel revenue over threshold amounts									0.30%
Annual percentage rent to be waived													2,500,000
Ground rent payable per year											5,126,000
Deferred rent due in December 2022									107,085,000
Deferred rent due in June 2024									42,915,000
Rental income	62,212,000	73,260,000							53,524,000	51,318,000
Accruals for unpaid rent, excluding any deferred rents						29,987,000	29,300,000
Adjustments included in rental income necessary to record rent on the straight line basis	62,000	354,000									(73,000)	357,000
Deferred rent accrued	610,000	1,309,000									610,000	729,000
Capital improvements from leased facilities, funded									22,655,000
Increase in minimum annual rent	5,287,000								1,926,000
Number of travel centers at which Shell has agreed to construct a network of natural gas refueling lanes								100
Aggregate purchase price advanced			150,500,000
Procurement and construction supervision fees															482,000	0
Loan secured by real estate property investment																					170,000,000
Number of hotels to be purchased under the agreement																					5
Number of other companies to which management services are provided holding shares in related party																		5
Equity method investments, ownership percentage																		12.50%
Amount invested in equity investee																		5,209,000
Equity method investments, carrying value																		5,697,000		5,629,000
Earnings (losses) recognized related to equity investments	76,000	45,000																76,000	45,000
Coverage of property insurance																		500,000,000
Period for which property insurance program was extended																	1 year
Annual premium for property insurance																	$ 5,256,000