Note 3 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Income Tax Expense (Benefit)	$ 6,650,000	$ (26,925,000)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	28,102,000	(102,549,000)
Effective Income Tax Rate Reconciliation, Realized Gains on Marketable Securities, Amount	110,000	3,790,000
Effective Income Tax Rate Reconciliation, Unrealized Gains (Losses) on Marketable Securities, Amount	4,140,000	32,840,000
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	2,803,000	1,735,000
Effective Income Tax Rate Reconciliation, Deduction, Dividends, Amount	$ 403,000	$ 340,000
Effective Income Tax Rate Reconciliation, Percent	23.70%	26.30%
(Provision) benefit for income taxes	$ (6,650,000)	$ 26,925,000
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ (28,102,000)	102,549,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount		730,000
Domestic Tax Authority [Member]
Open Tax Year	2019
State and Local Jurisdiction [Member]
Open Tax Year	2018
State and Local Jurisdiction [Member] | California Franchise Tax Board [Member]
Operating Loss Carryforwards Utilized		4,200,000
Operating Loss Carryforwards		5,500,000
State and Local Jurisdiction [Member] | California Franchise Tax Board [Member] | Operating Loss Carryforwards, Expire Fiscal Years 2038 and 2039 [Member]
Operating Loss Carryforwards		$ 1,300,000