Leases - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) Property State	Mar. 31, 2019 USD ($)	Jan. 01, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2019 USD ($)
Leases [Line Items]
Number of properties in portfolio | Property	947
Number of states in which our properties are located | State	35
Revenues from rental properties	$ 34,650	$ 33,287
Rental income contractually due from tenants in revenues from rental properties included in continuing operations	31,393	29,208
Revenue recognition adjustments included in revenues from rental properties in continuing operations	69	379
Real Estate Taxes and other municipal charges paid then reimbursed by tenants included in revenues and expenses	3,326	3,700
Lease origination costs	69	$ 93
Net investment in direct financing leases	80,806			$ 82,366
Net Investments in direct financing lease, lease payments receivable	123,153			126,412
Net Investment in direct financing lease, unguaranteed estimated residual value	13,928			13,928
Net Investment in direct financing lease, deferred income	55,698			57,974
Net Investment in direct financing lease, allowance for credit losses	577
Operating lease liabilities	19,982			21,844
Operating lease right of use assets	$ 19,341			$ 21,191
Accounting Standards Update 2016-13 [Member]
Leases [Line Items]
Net investment in direct financing leases			$ 82,366
Estimated credit loss reserve related to direct financing leases			$ 578
Accounting Standards Update 2016-02 [Member]
Leases [Line Items]
Operating lease liabilities					$ 26,087
Operating lease right of use assets					$ 25,561
Third Party Landlords [Member]
Leases [Line Items]
Number of properties leased | Property	62
Owned Properties [Member]
Leases [Line Items]
Number of properties | Property	885