Note 3 - Real Estate (Details Textual) $ in Thousands	1 Months Ended	3 Months Ended		5 Months Ended	6 Months Ended
	May 31, 2021	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	May 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Operating Lease, Lease Income, Total		$ 285,732	$ 235,961		$ 564,603	$ 521,965
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, Net of Tax, Attributable to Noncontrolling Interest					3,100
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation					$ 2,100
Acquired [Member]
Operating Lease, Lease Income, Total				$ 3,200
Disposition Activity Relating to Consolidated Operating Properties and Parcels [Member]
Number of Properties Sold	2				3	3
Rite Aid Distribution Center [Member]
Prepaid Rent		$ 17,700			$ 17,700