Note 7 - Investments in Joint Ventures - Condensed Income Statement of EXCOR and All Other Joint Ventures (Details) - USD ($)	12 Months Ended
	Aug. 31, 2025	Aug. 31, 2024
Net sales	$ 84,234,474	$ 85,059,517
Gross profit	31,676,555	33,786,362
Net income	17,619	5,409,082
NTIC’s share of equity in income from joint ventures	3,539,056	4,223,296
EXCOR and All Other Joint Ventures [Member]
Net income	7,081,482	8,450,411
NTIC’s share of equity in income from joint ventures	3,539,057	4,223,296
NTIC’s dividends received from joint ventures	1,566,946	2,997,164
EXCOR [Member]
Net income	3,325,785	4,599,088
NTIC’s share of equity in income from joint ventures	1,664,532	2,299,274
NTIC’s dividends received from joint ventures	0	1,624,950
All Other [Member]
Net income	1,372,804	3,851,323
NTIC’s share of equity in income from joint ventures	682,436	1,924,022
NTIC’s dividends received from joint ventures	548,805	1,372,214
Acobal [Member]
Net income	1,418,240
NTIC’s share of equity in income from joint ventures	708,333
NTIC’s dividends received from joint ventures	635,528
Zerust OY [Member]
Net income	964,653
NTIC’s share of equity in income from joint ventures	483,754
NTIC’s dividends received from joint ventures	382,613
EXCOR and All Other Joint Ventures [Member]
Net sales	91,236,272	95,940,014
Gross profit	39,460,739	41,247,036
EXCOR [Member]
Net sales	32,909,789	35,720,889
Gross profit	17,637,075	18,288,258
All Other [Member]
Net sales	41,774,073	60,219,125
Gross profit	14,346,567	$ 22,958,778
Acobal [Member]
Net sales	11,721,152
Gross profit	4,500,635
Zerust OY [Member]
Net sales	4,831,258
Gross profit	$ 2,976,462