Subsequent Events - Additional Information (Detail)		9 Months Ended
	Oct. 03, 2017 USD ($) Property Option	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Subsequent Event [Line Items]
Payments to acquire interests in fee simple properties | $		$ 143,885,000	$ 2,155,000
Applegreen PLC [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Number of properties with fee simple interests acquired | Property	38
Payments to acquire interests in fee simple properties | $	$ 68,300,000
Unitary lease description	The unitary lease provides for an initial term of 15 years, with four five-year renewal options. Rent is scheduled to increase on the fifth anniversary of the commencement of the lease and annually thereafter.
Unitary lease initial term	15 years
Number of unitary lease renewal options | Option	4
Unitary lease renewal term	5 years
Applegreen PLC [Member] | Republic of Ireland, the United Kingdom, and the United States [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Number of convenience stores and gasoline stations currently operated | Property	275