Note 10 - Reportable Operating Segments - Financial Results for Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating Segment Revenues
Operating revenues	$ 2,960	$ 9,336	$ 5,502	$ 19,019
Operating Segment Income (Loss)
Operating income (loss)	(431)	6,702	(1,256)	12,830
Operating Segments [Member]
Operating Segment Revenues
Operating revenues	2,960	9,336	5,502	19,019
Operating Segment Income (Loss)
Operating income (loss)	1,060	7,958	2,084	15,550
Operating Segments [Member] | Real Estate Segment [Member]
Operating Segment Revenues
Operating revenues	300	6,852	336	13,991
Operating Segment Income (Loss)
Operating income (loss)	(143)	6,700	(173)	13,103
Operating Segments [Member] | Leasing Segment [Member]
Operating Segment Revenues
Operating revenues	1,558	1,370	3,053	2,956
Operating Segment Income (Loss)
Operating income (loss)	852	783	1,769	1,900
Operating Segments [Member] | Utilities Segment [Member]
Operating Segment Revenues
Operating revenues	810	829	1,514	1,505
Operating Segment Income (Loss)
Operating income (loss)	290	403	473	526
Operating Segments [Member] | Resort Amenities Segment [Member]
Operating Segment Revenues
Operating revenues	292	285	599	567
Operating Segment Income (Loss)
Operating income (loss)	$ 61	$ 72	$ 15	$ 21