Note 14 - Share-based Compensation - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Number of Shares Outstanding, Beginning Balance (in shares)	3,394,858
Weighted Average Exercise Price, Shares Outstanding, Beginning Balance (in dollars per share)	$ 2.18
Number of Shares Granted (in shares)	0
Weighted Average Exercise Price, Shares Granted (in dollars per share)
Number of Shares Forfeited/expired (in shares)	(769,439)
Weighted Average Exercise Price, Shares Forfeited/expired (in dollars per share)	$ 2.99
Number of Shares Exercised (in shares)	(406,151)	(1,179,456)
Weighted Average Exercise Price, Exercised (in dollars per share)	$ 1.86
Number of Shares Outstanding, Ending Balance (in shares)	2,219,268	3,394,858
Weighted Average Exercise Price, Shares Outstanding, Ending Balance (in dollars per share)	$ 1.94	$ 2.18
Number of Shares Exercisable (in shares)	1,405,578
Weighted Average Exercise Price, Shares Exercisable (in dollars per share)	$ 1.93