Note 17 - Segment Information - Segment Disclosures (Details) - USD ($)	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018
Revenues	$ 10,177,559	$ 7,628,567
Operating Income	1,289,875	991,105
Depreciation and amortization	201,267	60,105
Interest expense	283,003	2,708,888
Long-lived assets	6,235,172		$ 6,452,061
Total assets	40,349,222		41,860,797
Intersegment Eliminations [Member]
Revenues	186,972
LRAD Segment [Member]
Revenues	9,656,702	7,628,567
Operating Income	1,302,646	991,105
Depreciation and amortization	124,301	60,105
Interest expense	283,003	2,708,888
Long-lived assets	2,386,399		2,478,144
Total assets	35,522,540		36,770,872
LRAD Segment [Member] | Intersegment Eliminations [Member]
Revenues
Genasys Segment [Member]
Revenues	520,857
Operating Income	(12,771)
Depreciation and amortization	76,966
Interest expense
Long-lived assets	3,848,773		3,973,917
Total assets	4,826,682		$ 5,089,925
Genasys Segment [Member] | Intersegment Eliminations [Member]
Revenues	$ 186,972