Note 11 - Revenue Streams and Concentrations (Details Textual) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Sep. 30, 2019
Revenue, Remaining Performance Obligation, Amount	$ 7.2	$ 7.2
Contract with Customer, Liability, Total			$ 3.6
Contract with Customer, Liability, Revenue Recognized	1.4
Short-term Contract with Customer [Member]
Revenue, Remaining Performance Obligation, Amount	1.2	1.2
Long-term Contract with Customer [Member]
Revenue, Remaining Performance Obligation, Amount	$ 6.0	$ 6.0
Long-term Contract with Customer [Member] | Minimum [Member]
Revenue, Expected to Recognize, Term		2 years
Long-term Contract with Customer [Member] | Maximum [Member]
Revenue, Expected to Recognize, Term		5 years