Note 10 - Reportable Operating Segments - Financial Results for Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating Segment Revenues
Operating revenues	$ 9,336	$ 17,977	$ 19,019	$ 20,954
Operating Segment Income
Operating income (loss)	6,500	13,849	12,426	13,033
Operating Segments [Member]
Operating Segment Revenues
Operating revenues	9,336	17,977	19,019	20,954
Operating Segment Income
Operating income (loss)	7,958	15,217	15,550	16,313
Operating Segments [Member] | Real Estate Segment [Member]
Operating Segment Revenues
Operating revenues	6,852	15,498	13,991	15,666
Operating Segment Income
Operating income (loss)	6,700	14,142	13,103	14,009
Operating Segments [Member] | Leasing Segment [Member]
Operating Segment Revenues
Operating revenues	1,370	1,277	2,956	2,892
Operating Segment Income
Operating income (loss)	783	732	1,900	1,634
Operating Segments [Member] | Utilities Segment [Member]
Operating Segment Revenues
Operating revenues	829	878	1,505	1,726
Operating Segment Income
Operating income (loss)	403	289	526	506
Operating Segments [Member] | Resort Amenities Segment [Member]
Operating Segment Revenues
Operating revenues	285	324	567	670
Operating Segment Income
Operating income (loss)	$ 72	$ 54	$ 21	$ 164