Note 12 - Leasing Arrangements - Rental Income under Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Minimum rentals	$ 712	$ 737	$ 1,410	$ 1,448
Percentage rentals	37	458	304	865
Licensing fees	111	231	345	465
Other (primarily common area recoveries)	321	292	608	618
Leasing	1,436	2,038	3,172	3,954
Total	1,436	2,038	3,172	3,954
Water System Sales [Member]
Leasing	255	320	505	558
Total	$ 255	$ 320	$ 505	$ 558