Note 3 - Investments in Related Parties - Equity Method Investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Loss recorded in the Consolidated Statements of Operations		$ 280	$ (0)
HC Government Realty Trust, Inc [Member]
Equity Method Investment, Ownership Percentage		27.40%	33.90%
Investment in affiliate, balance		$ 10,551	$ 10,850
Loss recorded in the Consolidated Statements of Operations	[1]	$ (213)	$ (435)
HC Government Realty Trust, Inc [Member] | Series B Cumulative Convertible Preferred Stock [Member]
Equity Method Investment, Ownership Percentage	[2]	26.30%	26.80%
Investment in affiliate, balance	[2]	$ 10,250	$ 10,250
Loss recorded in the Consolidated Statements of Operations	[1],[2]	$ 0	$ 0
HC Government Realty Trust, Inc [Member] | Common Stock of Investee [Member]
Equity Method Investment, Ownership Percentage		1.10%	7.10%
Investment in affiliate, balance		$ 301	$ 600
Loss recorded in the Consolidated Statements of Operations	[1]	$ (213)	$ (435)

[1] Loss from these investments is included in “Net loss from investments related parties” in the Consolidated Statements of Operations. Since HC Realty is a REIT and not a taxable entity, the loss is not reported net of taxes.

[2] Represents investments in shares of HC Series B Stock with a basis of $10.25 million. Each share of HC Series B Stock has voting rights on an as converted basis and can be converted into shares of HC Common Stock at a conversion ratio equal to $10.00 per share divided by the lesser of $9.10 per share or the fair market value per share of HC Common Stock, subject to adjustment upon the occurrence of certain events.