Note 12 - Leasing Arrangements - Rental Income under Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Minimum rentals	$ 697	$ 710
Percentage rentals	266	405
Licensing fees	234	234
Other (primarily common area recoveries)	290	327
Leasing	1,736	1,916
Total	1,736	1,916
Water System Sales [Member]
Leasing	249	240
Total	$ 249	$ 240