Note 2 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Balance at beginning of year	$ 250,000	$ 250,000	$ 250,000
Additions charged to costs and expenses	5,000	61,000	41,000
Accounts charged off less recoveries	(55,000)	(61,000)	(41,000)
Balance at end of year	$ 200,000	$ 250,000	$ 250,000