Related Person Transactions (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		0 Months Ended				1 Months Ended	3 Months Ended		9 Months Ended					0 Months Ended	3 Months Ended		9 Months Ended		0 Months Ended	3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended					1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013 Property item	Sep. 30, 2012	Sep. 30, 2013 Property item	Sep. 30, 2012	Jan. 31, 2012 SNSTA	Sep. 30, 2013 Full service hotel in Orlando, FL	Sep. 30, 2013 Travel centers Property	Sep. 30, 2013 Hotels Property	Jul. 31, 2013 RMR item	Sep. 30, 2013 RMR agreement Property item	Sep. 30, 2012 RMR	Sep. 30, 2013 RMR agreement Property item	Sep. 30, 2012 RMR	Sep. 20, 2013 RMR	Sep. 30, 2013 Travel Centers of America LLC item	Dec. 31, 2012 Travel Centers of America LLC	Jul. 02, 2013 Travel Centers of America LLC Travel centers Property	Sep. 30, 2013 Travel Centers of America LLC Travel centers item Property	Sep. 30, 2012 Travel Centers of America LLC Travel centers	Sep. 30, 2013 Travel Centers of America LLC Travel centers item Property	Sep. 30, 2012 Travel Centers of America LLC Travel centers	Apr. 15, 2013 Travel Centers of America LLC Travel centers Maximum Property	Sep. 30, 2013 Travel Centers of America LLC Travel centers TA No. 1 Property	Sep. 30, 2012 Travel Centers of America LLC Travel centers TA No. 1	Sep. 30, 2013 Travel Centers of America LLC Travel centers TA No. 1 Property	Sep. 30, 2012 Travel Centers of America LLC Travel centers TA No. 1	Sep. 30, 2013 Travel Centers of America LLC Travel centers TA No. 2 Property	Sep. 30, 2013 Travel Centers of America LLC Travel centers TA No. 2 Maximum item	Sep. 30, 2013 Sonesta Sonesta agreements	Sep. 30, 2012 Sonesta Sonesta agreements	Sep. 30, 2013 Sonesta Sonesta agreements	Sep. 30, 2012 Sonesta Sonesta agreements	Sep. 30, 2013 Sonesta Hotels Property	Jul. 02, 2013 Sonesta Hotels Sonesta agreements	Jul. 02, 2013 Sonesta Hotels Maximum Sonesta agreements	Jun. 30, 2013 AIC	Sep. 30, 2013 AIC	Sep. 30, 2012 AIC	Sep. 30, 2013 AIC item	Sep. 30, 2012 AIC	Dec. 31, 2012 AIC	Sep. 30, 2013 AIC Maximum
Related Person Transactions
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%
Lessee as percentage of real estate properties															36.00%
Number of management agreements or leases	11		11															2		2
Number of properties leased																		184		184			144		144		40
Term of renewal option																											15 years
Percentage of non-fuel revenue over threshold amounts																		3.00%		3.00%
Percentage of fuel revenue over threshold amounts																		0.30%		0.30%
Ground rent payable per year																									$ 5,152
Deferred rent due in December 2022																		107,085		107,085
Deferred rent due in June 2024																		42,915		42,915
Rental income	62,731	73,915	186,799	220,863														54,560	51,717	162,034	154,626
Adjustments included in rental income necessary to record rent on the straight line basis	173	(52)	272	243																			(83)	(69)	(239)	218
Accruals for unpaid rent, excluding any deferred rents															31,368	29,300
Deferred rent accrued	464	919	1,746	3,481																			464	77	1,746	1,277
Estimated annual percentage rent waived																											307
Annual percentage rent to be waived																											2,500
Capital improvements from leased facilities, funded																				63,163
Increase in minimum annual rent			19,135														537			5,369
Increase in annual rent payable by TA as a percentage of the total investment																	8.50%
Number of employees	0		0
Number of agreements to provide management and administrative services										2		2
Number of properties	475		475				184	291									3
Number of properties under property management agreement										1		1
Number of Managing Trustees who are Chairmen, majority owners and employees of RMR										1		1
Business and property management agreement expenses										10,744	8,068	30,711	26,650																2,797	1,903	7,462	3,536
Base business management fee payable in common shares (as a percent)														10.00%
Number of entities to whom RMR provides management services									5
Aggregate coverage of combined directors' and officers' liability insurance policy purchased by the related party									10,000
Aggregate coverage of separate directors' and officers' liability insurance policy purchased									5,000
Premium paid for combined directors' and officers' liability insurance policy									338
Number of Managing Trustees who are Managing Directors															1
Number of renewal options available																												2
Number of travel centers at which Shell has agreed to construct a network of natural gas fueling lanes																						100
Aggregate purchase price to acquire entity					150,500
Number of properties included in management agreement																																	22
Purchase price excluding closing cost						21,000											6,325
Procurement and construction supervision fees																													699	185	2,322	209
Cost allocation for reimbursement or other credit as a percentage of applicable hotel's room revenues																																			1.00%
Cost allocation for reimbursement or other credit as a percentage of total revenues																																		1.00%
Reservation transmission expenses reimbursement as a percentage of applicable hotel's room revenues																																		0.80%
Number of other companies to which management services are provided holding shares in related party																																							5
Equity method investments, ownership percentage																																					12.50%		12.50%			20.00%
Amount invested in equity investee																																					5,209		5,209
Equity method investments, carrying value																																					5,781		5,781		5,629
Earnings (losses) recognized related to equity investments	64	115	219	236																																	64	115	219	236
Coverage of property insurance																																							500,000
Period for which property insurance program was extended																																				1 year
Annual premium for property insurance																																				$ 6,842