Note 4 - Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Investment income	$ 423	$ 356
Less: Investment expense	(1)	(1)
Cash and Cash Equivalents [Member]
Investment income	103	63
Fixed Income Securities [Member]
Investment income	29	38
Series B Cumulative Convertible Preferred Stock [Member] | HC Government Realty Trust, Inc [Member]
Dividends on investment in HC Series B Stock	256	256
Partnership [Member]
Investment income	$ 36	$ 0