Management Agreements and Leases - TA (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) agreement travelcenter	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) agreement travelcenter	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Management Agreements and Leases [Line Items]
Number of operating agreements | agreement		13		13
Revenues		$ 603,153	$ 577,588	$ 1,743,737	$ 1,636,793
Adjustments necessary to record rent on straight line basis		$ 3,136	3,087	9,359	9,208
Capital improvements from leased facilities, funded				$ 111,248	89,955
Travel centers
Management Agreements and Leases [Line Items]
Number of properties owned | travelcenter		199		199
Travel Centers of America LLC | Travel centers
Management Agreements and Leases [Line Items]
Adjustments necessary to record rent on straight line basis		$ 3,037	2,988	$ 9,066	8,907
Accruals for unpaid rent, including deferred rent		88,164		$ 88,164		$ 78,513
Increase in annual rent fixed interest rate				8.50%
Capital improvements from leased facilities, funded				$ 44,653	62,888
Increase (decrease) in minimum annual rent				3,795	5,345
Deferred rent receivable from TA agreement, during the period		$ 934	435	$ 2,630	1,384
TA agreements | Travel centers
Management Agreements and Leases [Line Items]
Number of operating agreements | agreement		5		5
TA agreements | Forecast | Travel centers
Management Agreements and Leases [Line Items]
Capital improvements from leased facilities, funded	$ 13,600
Rental income
Management Agreements and Leases [Line Items]
Revenues		$ 80,690	80,896	$ 243,701	240,274
Rental income | Travel Centers of America LLC | Travel centers
Management Agreements and Leases [Line Items]
Revenues		$ 74,797	$ 73,279	$ 223,458	$ 217,420