Note 6 - Investments in Joint Ventures (Details) - Condensed Income Statement of EXCOR and NTI ASEAN, and All Other Joint Ventures: (USD $)	3 Months Ended
	Nov. 30, 2014	Nov. 30, 2013
Condensed Income Statements, Captions [Line Items]
Net sales	$ 29,120,852	$ 29,661,218
Gross profit	14,035,784	14,166,070
Net income	3,184,570	2,837,565
Company’s share of equity in income of joint ventures	1,606,683	1,427,748
EXCOR [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	9,524,270	9,476,403
Gross profit	4,974,751	5,063,662
Net income	1,956,191	1,853,307
Company’s share of equity in income of joint ventures	978,096	926,654
China [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	3,735,457	4,294,138
Gross profit	1,783,673	2,016,809
Net income	265,648	298,708
Company’s share of equity in income of joint ventures	132,824	149,354
All Other [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	15,861,125	15,890,677
Gross profit	7,277,360	7,085,599
Net income	962,731	685,550
Company’s share of equity in income of joint ventures	$ 495,763	$ 351,740