Real Estate Properties - Allocation of Purchase Price (Details) $ in Thousands																										12 Months Ended
	Sep. 28, 2017 USD ($)	Sep. 26, 2017 USD ($) hotel state room	Sep. 08, 2017 USD ($)	Aug. 23, 2017 USD ($) room	Aug. 01, 2017 USD ($) room	Jun. 29, 2017 USD ($) room	Jun. 02, 2017 USD ($) room	May 03, 2017 USD ($)	Mar. 31, 2017 USD ($) room	Feb. 01, 2017 USD ($) room	Dec. 05, 2016 USD ($) room	Sep. 30, 2016 USD ($)	Sep. 14, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 22, 2016 USD ($) travelcenter	Mar. 31, 2016 USD ($) travelcenter	Mar. 16, 2016 USD ($) room	Feb. 01, 2016 USD ($) hotel room	Oct. 30, 2015 USD ($)	Sep. 23, 2015 USD ($)	Jul. 23, 2015 USD ($) hotel state room	Jun. 01, 2015 USD ($) travelcenter	May 15, 2015 USD ($) room	Apr. 28, 2015 USD ($)	Mar. 16, 2015 USD ($) room	Dec. 31, 2017 USD ($) hotel travelcenter	Dec. 31, 2016 USD ($) hotel travelcenter	Dec. 31, 2015 USD ($) hotel travelcenter
Real Estate Properties [Line Items]
Asset acquisition, purchase price																										$ 606,054	$ 254,738	$ 492,883
Asset acquisition, land																										104,438
Business combination and asset acquisition, land																											37,619	60,849
Asset acquisition, land improvements																										15,337
Business combination and asset acquisition, land improvements																											24,402	93,327
Asset acquisition, building and improvements																										448,345
Business combination and asset acquisition, building and improvements																											181,332	321,573
Asset acquisition, furniture, fixtures and equipment																										35,252
Business combination and asset acquisition, furniture, fixtures and equipment																											11,385	16,873
Asset acquisition, intangible assets																										2,682
Business combination and asset acquisition, intangible assets																											0	261
Hotels and travel centers
Real Estate Properties [Line Items]
Increase (decrease) in annual minimum returns and rents																										$ 10,274	$ 14,740	$ 14,691
Hotels
Real Estate Properties [Line Items]
Number of properties acquired | hotel																										20	4	11
Hotels | Hotel Allegro, Chicago, IL
Real Estate Properties [Line Items]
Asset acquisition, purchase price										$ 86,201
Asset acquisition, land										13,609
Asset acquisition, land improvements										40
Asset acquisition, building and improvements										58,929
Asset acquisition, furniture, fixtures and equipment										11,926
Asset acquisition, intangible assets										$ 1,697
Number of rooms | room										483
Acquisition costs capitalized										$ 707
Hotels | Hotel Alexis, Seattle, WA
Real Estate Properties [Line Items]
Asset acquisition, purchase price									$ 72,736
Asset acquisition, land									24,460
Asset acquisition, land improvements									30
Asset acquisition, building and improvements									46,944
Asset acquisition, furniture, fixtures and equipment									855
Asset acquisition, intangible assets									$ 447
Number of rooms | room									121
Acquisition costs capitalized									$ 1,111
Hotels | Crowne Plaza Ravinia, Atlanta, GA
Real Estate Properties [Line Items]
Asset acquisition, purchase price						$ 88,748
Asset acquisition, land						16,612
Asset acquisition, land improvements						483
Asset acquisition, building and improvements						68,864
Asset acquisition, furniture, fixtures and equipment						2,789
Asset acquisition, intangible assets						$ 0
Number of rooms | room						495
Acquisition costs capitalized						$ 144
Hotels | Crowne Plaza & Lofts, Columbus, OH
Real Estate Properties [Line Items]
Asset acquisition, purchase price					$ 49,188
Asset acquisition, land					6,100
Asset acquisition, land improvements					49
Asset acquisition, building and improvements					40,678
Asset acquisition, furniture, fixtures and equipment					2,361
Asset acquisition, intangible assets					$ 0
Number of rooms | room					419
Acquisition costs capitalized					$ 198
Hotels | Crowne Plaza Hotel, Charlotte, NC
Real Estate Properties [Line Items]
Asset acquisition, purchase price				$ 44,000
Asset acquisition, land				2,684
Asset acquisition, land improvements				1,012
Asset acquisition, building and improvements				35,288
Asset acquisition, furniture, fixtures and equipment				5,016
Asset acquisition, intangible assets				$ 0
Number of rooms | room				300
Acquisition costs capitalized				$ 143
Hotels | Crowne Plaza, Atlanta Airport
Real Estate Properties [Line Items]
Asset acquisition, purchase price			$ 940
Asset acquisition, land			940
Asset acquisition, land improvements			0
Asset acquisition, building and improvements			0
Asset acquisition, furniture, fixtures and equipment			0
Asset acquisition, intangible assets			0
Acquisition costs capitalized			$ 40
Hotels | Various Locations Acquired for Sonesta Conversion
Real Estate Properties [Line Items]
Number of properties acquired | hotel		14
Asset acquisition, purchase price		$ 139,885
Asset acquisition, land		30,712
Asset acquisition, land improvements		6,390
Asset acquisition, building and improvements		93,872
Asset acquisition, furniture, fixtures and equipment		8,911
Asset acquisition, intangible assets		$ 0
Number of rooms | room		1,653
Acquisition costs capitalized		$ 1,885
Number of states in which property is located | state		12
Hotels | Cleveland and Westlake, OH
Real Estate Properties [Line Items]
Number of properties acquired | hotel																		2
Business combination, purchase price																		$ 12,000
Business combination, land																		1,953
Business combination, land improvements																		654
Business combination, buildings and improvements																		8,153
Business combination, furniture, fixtures and equipment																		1,240
Business combination, intangible assets																		$ 0
Number of rooms | room																		262
Hotels | Kimpton Hotel Monaco, Portland, OR
Real Estate Properties [Line Items]
Business combination, purchase price																	$ 114,000
Business combination, land																	5,657
Business combination, land improvements																	3
Business combination, buildings and improvements																	100,535
Business combination, furniture, fixtures and equipment																	7,805
Business combination, intangible assets																	$ 0
Number of rooms | room																	221
Hotels | InterContinental, Rosemont, Il
Real Estate Properties [Line Items]
Business combination, purchase price																									$ 35,500
Business combination, land																									2,375
Business combination, land improvements																									219
Business combination, buildings and improvements																									31,182
Business combination, furniture, fixtures and equipment																									1,463
Business combination, intangible assets																									$ 261
Number of rooms | room																									300
Hotels | Sonesta Hotel, Ft. Lauderdale, FL
Real Estate Properties [Line Items]
Business combination, purchase price																								$ 750
Asset acquisition, purchase price																								750
Asset acquisition, land																								165
Asset acquisition, land improvements																								0
Asset acquisition, building and improvements																								585
Asset acquisition, furniture, fixtures and equipment																								0
Asset acquisition, intangible assets																								0
Capitalized acquisition related costs																								$ 41
Hotels | Crowne Plaza Hotel, Denver CO
Real Estate Properties [Line Items]
Business combination, purchase price																							$ 77,250
Business combination, land																							8,193
Business combination, land improvements																							181
Business combination, buildings and improvements																							61,005
Business combination, furniture, fixtures and equipment																							7,871
Business combination, intangible assets																							$ 0
Number of rooms | room																							364
Hotels | Various locations acuired in July
Real Estate Properties [Line Items]
Number of properties acquired | hotel																					9
Business combination, purchase price																					$ 85,000
Business combination, land																					13,165
Business combination, land improvements																					0
Business combination, buildings and improvements																					64,338
Business combination, furniture, fixtures and equipment																					7,497
Business combination, intangible assets																					$ 0
Number of states in which property is located | state																					8
Number of suites | room																					1,095
Travel centers
Real Estate Properties [Line Items]
Number of properties acquired | travelcenter																										1	5	14
Number of properties where certain assets were acquired | travelcenter																												11
Travel centers | Holbrook, AZ
Real Estate Properties [Line Items]
Asset acquisition, purchase price													$ 325
Asset acquisition, land													325
Asset acquisition, land improvements													0
Asset acquisition, building and improvements													0
Asset acquisition, furniture, fixtures and equipment													0
Asset acquisition, intangible assets													0
Acquisition costs capitalized													7
Increase (decrease) in annual minimum returns and rents													$ 28
Sonesta agreements | Hotels | Chase Park Plaza Hotel, St. Louis, MO
Real Estate Properties [Line Items]
Asset acquisition, purchase price							$ 88,080
Asset acquisition, land							4,250
Asset acquisition, land improvements							161
Asset acquisition, building and improvements							79,737
Asset acquisition, furniture, fixtures and equipment							3,394
Asset acquisition, intangible assets							$ 538
Number of rooms | room							389
Acquisition costs capitalized							$ 466
Sonesta agreements | Hotels | Sonesta Hotel, Milpitas, CA
Real Estate Properties [Line Items]
Business combination, purchase price											$ 46,000
Business combination, land											13,089
Business combination, land improvements											823
Business combination, buildings and improvements											29,748
Business combination, furniture, fixtures and equipment											2,340
Business combination, intangible assets											$ 0
Number of rooms | room											236
Travel Centers of America LLC | Travel centers
Real Estate Properties [Line Items]
Number of properties acquired | travelcenter																						14
Number of properties where certain assets were acquired | travelcenter																						11
Asset acquisition, purchase price																						$ 279,383
Travel Centers of America LLC | Travel centers | Columbia, SC
Real Estate Properties [Line Items]
Asset acquisition, purchase price								$ 27,604
Asset acquisition, land								4,040
Asset acquisition, land improvements								7,172
Asset acquisition, building and improvements								16,392
Asset acquisition, furniture, fixtures and equipment								0
Asset acquisition, intangible assets								$ 0
Travel Centers of America LLC | Travel centers | Sayre, OK
Real Estate Properties [Line Items]
Asset acquisition, purchase price	$ 8,672
Asset acquisition, land	1,031
Asset acquisition, land improvements	0
Asset acquisition, building and improvements	7,641
Asset acquisition, furniture, fixtures and equipment	0
Asset acquisition, intangible assets	0
Acquisition costs capitalized	72
Increase (decrease) in annual minimum returns and rents	$ 731
Annual minimum returns and rents, percentage of purchase price	8.50%
Travel Centers of America LLC | Travel centers | Hillsboro, TX [Member]
Real Estate Properties [Line Items]
Asset acquisition, purchase price																$ 19,683
Asset acquisition, land																4,834
Asset acquisition, land improvements																4,196
Asset acquisition, building and improvements																10,653
Asset acquisition, furniture, fixtures and equipment																0
Asset acquisition, intangible assets																$ 0
Travel Centers of America LLC | Travel centers | Various Travel Centers Acquired in June 2016
Real Estate Properties [Line Items]
Asset acquisition, purchase price															$ 23,876
Asset acquisition, land															3,170
Asset acquisition, land improvements															9,280
Asset acquisition, building and improvements															11,426
Asset acquisition, furniture, fixtures and equipment															0
Asset acquisition, intangible assets															$ 0
Travel Centers of America LLC | Travel centers | Wilmington, IL
Real Estate Properties [Line Items]
Asset acquisition, purchase price														$ 22,297
Asset acquisition, land														6,523
Asset acquisition, land improvements														3,364
Asset acquisition, building and improvements														12,410
Asset acquisition, furniture, fixtures and equipment														0
Asset acquisition, intangible assets														$ 0
Travel Centers of America LLC | Travel centers | Caryville, TN
Real Estate Properties [Line Items]
Asset acquisition, purchase price												$ 16,557
Asset acquisition, land												2,068
Asset acquisition, land improvements												6,082
Asset acquisition, building and improvements												8,407
Asset acquisition, furniture, fixtures and equipment												0
Asset acquisition, intangible assets												$ 0
Travel Centers of America LLC | Travel centers | Various Travel Centers Acquired in June 2015
Real Estate Properties [Line Items]
Asset acquisition, purchase price																						227,877
Asset acquisition, land																						26,286
Asset acquisition, land improvements																						67,161
Asset acquisition, building and improvements																						134,388
Asset acquisition, furniture, fixtures and equipment																						42
Asset acquisition, intangible assets																						$ 0
Travel Centers of America LLC | Travel centers | Various Travel Centers Acquired in September 2015
Real Estate Properties [Line Items]
Asset acquisition, purchase price																				$ 51,506
Asset acquisition, land																				9,165
Asset acquisition, land improvements																				21,266
Asset acquisition, building and improvements																				21,075
Asset acquisition, furniture, fixtures and equipment																				0
Asset acquisition, intangible assets																				$ 0
Travel Centers of America LLC | Travel centers | Waterloo, NY
Real Estate Properties [Line Items]
Business combination, purchase price																			$ 15,000
Asset acquisition, purchase price																			15,000
Asset acquisition, land																			1,500
Asset acquisition, land improvements																			4,500
Asset acquisition, building and improvements																			9,000
Asset acquisition, furniture, fixtures and equipment																			0
Asset acquisition, intangible assets																			0
Increase (decrease) in annual minimum returns and rents																			$ 1,275
Annual minimum returns and rents, percentage of purchase price																			8.50%
Travel Centers of America LLC | Travel centers under development
Real Estate Properties [Line Items]
Number of properties acquired | travelcenter															2	1
Number of properties with agreements to acquire | travelcenter																						4
Number of properties transfered as part of the purchase price | travelcenter																						2