Note 7 - Major Customer Concentration (Details Textual) - Customer Concentration Risk [Member]  | 
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2019  | 
Jun. 30, 2018  | 
Jun. 30, 2019  | 
Jun. 30, 2018  | 
Sep. 30, 2018  | 
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| Revenue Benchmark [Member] | Customer A [Member] | |||||
| Concentration Risk, Percentage | 19.00% | 20.00% | 18.00% | 22.00% | |
| Revenue Benchmark [Member] | Customer B [Member] | |||||
| Concentration Risk, Percentage | 12.00% | 13.00% | 10.00% | 14.00% | |
| Revenue Benchmark [Member] | Customer C [Member] | |||||
| Concentration Risk, Percentage | 11.00% | ||||
| Accounts Receivable [Member] | Customer A [Member] | |||||
| Concentration Risk, Percentage | 17.00% | 10.00% | |||
| Accounts Receivable [Member] | Customer B [Member] | |||||
| Concentration Risk, Percentage | 15.00% | ||||
| Accounts Receivable [Member] | Customer C [Member] | |||||
| Concentration Risk, Percentage | 35.00% | ||||
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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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