Real Estate and Intangibles - Additional Information (Detail)		3 Months Ended	9 Months Ended	12 Months Ended
	Oct. 03, 2024 USD ($)	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2022 USD ($) ft²	Dec. 31, 2024 USD ($) Property Land	Dec. 31, 2023 USD ($) Property	Dec. 31, 2022 USD ($)	Jul. 31, 2024 USD ($)
Real Estate Properties [Line Items]
Gain on sale of property				$ 171,000		$ 13,590,000
Revenues				302,052,000	$ 287,227,000	293,606,000
Net income				19,553,000	18,804,000	31,474,000
Acquisition-related expenses				1,878,000	1,661,000	1,370,000
Net proceeds from the sale of operating property				2,173,000		202,416,000
Gain on the sale of real estate				171,000		13,590,000
Impairment loss						5,540,000
Amortization of intangible assets				20,300,000	21,100,000	25,700,000
Amortization of above- / below-market leases				(1,935,000)	$ (2,730,000)	(3,105,000)
Lincoln, Nebraska [Member] | Land [Member]
Real Estate Properties [Line Items]
Consideration received							$ 2,300,000
Assets held for sale				2,000,000
Gross sales price	$ 2,300,000
Gain on sale of property				200,000
Gain on the sale of real estate				$ 200,000
CALIFORNIA
Real Estate Properties [Line Items]
Number of properties | Property				18	18
Operating Properties Acquired [Member]
Real Estate Properties [Line Items]
Number of properties | Property					0
Weighted average amortization period				9 years 1 month 13 days	10 years 5 months 15 days
Revenues				$ 7,200,000	$ 1,500,000
Net income				2,900,000	400,000
Acquisition-related expenses				$ 1,900,000	$ 1,700,000
JUD - Flagstaff [Member] | Operating Properties and Land Parcel Acquired [Member]
Real Estate Properties [Line Items]
Number of land parcel acquired | Land				1
ICE - Dallas, HSI - Orlando, ICE - Orlando, Northrop Grumman - Dayton, Northrop Grumman - Aurora, IRS - Ogden [Member] | Operating Properties and Land Parcel Acquired [Member]
Real Estate Properties [Line Items]
Number of properties | Property				9
Cary, NC [Member] | Operating Properties and Land Parcel Acquired [Member] | Building Facility [Member]
Real Estate Properties [Line Items]
Number of properties | Property				3
ICE - Dallas, HSI - Orlando, ICE - Orlando, Northrop Grumman - Dayton, Northrop Grumman - Aurora, IRS - Ogden, Cary, NC [Member] | Operating Properties and Land Parcel Acquired [Member]
Real Estate Properties [Line Items]
Aggregate purchase price				$ 184,900,000
CA - Anaheim, DHS - Atlanta and JUD - Newport News [Member] | Operating Properties and Land Parcel Acquired [Member]
Real Estate Properties [Line Items]
Number of properties | Property					3
Aggregate purchase price					$ 63,100,000
ICE Otay [Member]
Real Estate Properties [Line Items]
Impairment loss		$ 5,500,000	$ 5,500,000	$ 0	$ 0	$ 5,500,000
ICE Otay [Member] | CALIFORNIA
Real Estate Properties [Line Items]
Area of properties acquired | ft²		47,919	47,919