Note 4 - Investment in Affiliate (Details Textual) - HC Government Realty Trust, Inc [Member] - USD ($)	Mar. 19, 2019	Mar. 31, 2020
Series B Cumulative Convertible Preferred Stock [Member]
Equity Method Investment, Shares Purchased During Period (in shares)	200,000
Preferred Stock, Dividend Rate, Percentage	10.00%
Equity Method Investment, Aggregate Cost	$ 2,000,000
Convertible Preferred Stock of Investee, Shares Issued Upon Conversion (in shares)		1
Convertible Preferred Stock, Maximum Conversion Price (in dollars per share)		$ 9.10
Series B Cumulative Convertible Preferred Stock [Member] | Investors Affiliated with the Hale Partnership [Member]
Equity Method Investment, Shares Purchased During Period (in shares)	850,000
Equity Method Investment, Aggregate Cost	$ 8,500,000
Common Stock of Investee [Member]
Equity Method Investment, Shares Purchased During Period (in shares)	300,000
Equity Method Investment, Aggregate Cost	$ 3,000,000
Common Stock of Investee [Member] | Investors Affiliated with the Hale Partnership [Member]
Equity Method Investment, Shares Purchased During Period (in shares)	850,000