Note 6 - Investments in Joint Ventures - Condensed Income Statement of EXCOR and All Other Joint Ventures (Details) - USD ($)	12 Months Ended
	Aug. 31, 2024	Aug. 31, 2023
Net sales	$ 85,059,517	$ 79,902,952
Gross profit	33,786,362	27,803,831
Net income	5,409,082	2,912,276
NTIC’s share of equity in income of joint ventures	4,223,296	6,452,719
EXCOR and All Other Joint Ventures [Member]
Net income	8,450,411	8,934,198
NTIC’s share of equity in income of joint ventures	4,223,296	6,452,719
NTIC’s dividends received from joint ventures	2,997,164	5,639,198
EXCOR [Member]
Net income	4,599,088	5,730,311
NTIC’s share of equity in income of joint ventures	2,299,274	2,852,229
NTIC’s dividends received from joint ventures	1,624,950	2,459,500
All Other [Member]
Net income	3,851,323	3,203,887
NTIC’s share of equity in income of joint ventures	1,924,022	3,600,490
NTIC’s dividends received from joint ventures	1,372,214	3,179,698
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Net sales	95,940,014	100,682,316
Gross profit	41,247,036	40,096,561
EXCOR [Member]
Net sales	35,720,889	39,642,380
Gross profit	18,288,258	19,016,389
All Other [Member]
Net sales	60,219,125	61,039,936
Gross profit	$ 22,958,778	$ 21,080,172