Note 11 - Stock Options - Summary of Expired Director Plans (Details)	3 Months Ended
	Dec. 31, 2017 $ / shares shares
Range of Exercise Price, Lower Limit (in dollars per share)	$ 2.925
Outstanding Stock Options (in shares) | shares	5,000
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.54
Weighted Average Remaining Life (Year)
Number of Stock Options Exercisable (in shares) | shares	5,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 3.54
Exercise Price Range 1 [Member]
Outstanding Stock Options (in shares) | shares	4,000
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 2.925
Weighted Average Remaining Life (Year)	3 years 328 days
Number of Stock Options Exercisable (in shares) | shares	4,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 2.925
Range of Exercise Price, Upper Limit (in dollars per share)	$ 6
Exercise Price Range 2 [Member]
Outstanding Stock Options (in shares) | shares	1,000
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 6
Weighted Average Remaining Life (Year)	2 years 36 days
Number of Stock Options Exercisable (in shares) | shares	1,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 6