Note 3 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Income Tax Expense (Benefit), Total	$ 185,000	$ (6,260,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total	$ 4,226,000	$ (31,476,000)
Effective Income Tax Rate Reconciliation, Percent, Total	4.40%	19.90%
Income Tax Expense (Benefit) From CARES Act		$ (187,000)
Marketable Securities, Unrealized Gain (Loss), Total	$ 3,099,000
Income Tax Expense (Benefit), Recorded as a Temporary Difference in Deferred Income Tax	(1,371,000)
Marketable Securities, Realized Gain (Loss), Total	$ 4,193,000	$ 0
Domestic Tax Authority [Member]
Open Tax Year	2016 2017 2018 2019
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards, Total	$ 20,100,000
Domestic Tax Authority [Member] | California Franchise Tax Board [Member]
Operating Loss Carryforwards, Total	6,100,000
Domestic Tax Authority [Member] | Other State [Member]
Operating Loss Carryforwards, Total	$ 2,600,000