Leases - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($) Property State	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) Property State	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jan. 01, 2019 USD ($)
Leases [Line Items]
Number of properties in portfolio | Property	1,053		1,053
Number of states in which our properties are located | State	39		39
Revenues from rental properties	$ 43,658,000	$ 40,814,000	$ 86,025,000	$ 79,797,000
Rental income contractually due from tenants in revenues from rental properties included in continuing operations	39,917,000	37,175,000	78,963,000	73,600,000
Revenue recognition adjustments included in revenues from rental properties in continuing operations	189,000	449,000	447,000	1,025,000
Real Estate Taxes and other municipal charges paid then reimbursed by tenants included in revenues and expenses	3,930,000	$ 4,088,000	7,509,000	$ 7,223,000
Operating lease liabilities	17,307,000		17,307,000		$ 19,959,000
Operating lease right of use assets	$ 15,730,000		15,730,000		18,193,000
Accounting Standards Update 2016-02 [Member]
Leases [Line Items]
Operating lease liabilities						$ 26,087,000
Operating lease right of use assets						$ 25,561,000
Accounting Standards Update 2016-13 [Member]
Leases [Line Items]
Net Investment in direct financing lease, additional allowance for credit losses			$ 895,000		$ 895,000
Third Party Landlords [Member]
Leases [Line Items]
Number of properties leased | Property	39		39
Owned Properties [Member]
Leases [Line Items]
Number of properties | Property	1,014		1,014