Note 2 - Summary of Significant Accounting Policies (Details Textual)	3 Months Ended									12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Revenue, Net	$ 11,754,219	$ 10,892,868	$ 7,220,626	$ 3,346,315	$ 2,356,926	$ 2,692,040	$ 1,530,244	$ 1,046,624	$ 1,376,872	$ 23,816,735	$ 6,645,780	$ 5,852,924
Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Number of Customers										0	1	1
Revenue, Net										$ 0
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | One Customer [Member]
Revenue, Net											$ 1,300,000	$ 2,200,000
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Commercial Air Handling [Member]
Number of Customers	2
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Commercial Air Handling [Member] | Two Customers [Member]
Concentration Risk, Percentage	22.00%