Real Estate Acquisitions and Dispositions - Real Estate Acquisitions (Details) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) real_estate_property	Mar. 31, 2020 real_estate_property	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Business Acquisition [Line Items]
Proceeds from sale of land		$ 300
Loss on sale of land	$ 0	$ (300)		$ 0	$ (313)	$ 0
Operating lease, liability, statement of financial position	us-gaap:OtherLiabilities				us-gaap:OtherLiabilities
Operating lease, right-of-use asset, statement of financial position	us-gaap:OtherAssets				us-gaap:OtherAssets
Acquisition Of Properties During 3rd Quarter 2020 | Jensen Beach, FL (Land)
Business Acquisition [Line Items]
Purchase Price	$ 1,100				$ 1,050
Acquisition Of Properties During 2nd Quarter 2020
Business Acquisition [Line Items]
Number of real estate properties acquired | real_estate_property		7
Percentage of properties that were leased at acquisition		100.00%
Pro forma information, revenue of acquiree since acquisition date, actual					500
Pro forma information, earnings or loss of acquiree since acquisition date, actual					200
Transaction costs	400				400
Acquisition Of Properties During 1st Quarter 2020
Business Acquisition [Line Items]
Number of real estate properties acquired | real_estate_property			6
Percentage of properties that were leased at acquisition			98.20%
Pro forma information, revenue of acquiree since acquisition date, actual					2,600
Pro forma information, earnings or loss of acquiree since acquisition date, actual					1,500
Transaction costs	$ 200				$ 200