Note 9 - Fair Value of Assets and Liabilities - Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis (Details) - Warrant [Member] - USD ($)	12 Months Ended
	Sep. 30, 2020		Sep. 30, 2019
Balance	$ 3,925,000		$ 3,279,000
Net realized gains or (losses)
Net change in unrealized appreciation (deprediation)	(2,401,000)		(73,000)
Purchases
Sales
Transfer into level 3	75,000	[1]	883,000	[2]
Transfer out of level 3	(524,000)	[3]	(164,000)
Balance	$ 1,075,000		$ 3,925,000

[1] The Company received warrants as part of investment banking transaction.

[2] The Company received warrants as part of a transactions.

[3] Transfer out consist of a transfer to Level 2 of a warrant as the underlying security became a publicly registered security and a warrant exercise.