Note 9 - Investments in Marketable Securities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Equity Securities Fv Ni Gross Unrealized Gain	$ 115,259,000	$ 84,514,000
Equity Securities Fv Ni Gross Unrealized Loss	715,000	928,000
Equity Securities, FV-NI, Unrealized Gain (Loss)	30,958,000	14,944,000	$ (15,806,000)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	135,000	326,000
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	5,449,000	7,937,000
Proceeds from Sale and Maturity of Marketable Securities	51,970,000	47,396,000	49,961,000
Debt Securities, Realized Gain (Loss)	$ 1,093,000	$ (667,000)	$ (1,326,000)