Note 4 - Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Investment income	$ 333	$ 325	$ 489	$ 886
Less: Investment expense	0	(2)	(1)	(4)
Cash and Cash Equivalents [Member]
Investment income	89	70	272	273
Fixed Income Securities [Member]
Investment income	0	35	1	88
Series B Cumulative Convertible Preferred Stock [Member] | HC Government Realty Trust, Inc [Member]
Dividends on investment in HC Series B Stock	0	0	0	256
Partnership [Member]
Investment income	$ 244	$ 222	$ 217	$ 273