Note 11 - Segment and Geographic Information - Net Sales by Geographic Location (Details) - USD ($)	3 Months Ended		9 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2019	May 31, 2018
Net sales by segment	$ 14,893,117	$ 12,923,837	$ 42,302,573	$ 36,680,850
Inside the USA to Unaffiliated Customers [Member]
Net sales by segment	6,172,882	7,434,991	19,564,756	19,771,031
Joint Ventures in Which the Company is a Shareholder Directly and Indirectly Outside the USA [Member]
Net sales by segment	1,112,313	879,324	2,304,455	2,201,077
Unaffiliated Customers Outside the USA [Member]
Net sales by segment	$ 7,607,922	$ 4,609,522	$ 20,433,362	$ 14,708,742