Note 7 - Investments in Joint Ventures - Condensed Balance Sheet of EXCOR and All Other Joint Ventures (Details) - USD ($)	Aug. 31, 2025	Aug. 31, 2024
Current assets	$ 44,342,816	$ 41,579,219
Total assets	102,745,280	94,676,502
Current liabilities	23,904,094	17,896,943
Non-current liabilities	2,128,461	1,604,238
Joint ventures’ equity	72,148,754	71,193,991
Investments in joint ventures	28,611,777	25,397,287
EXCOR and All Other Joint Ventures [Member]
Investments in joint ventures	28,611,777	25,397,287
NTIC’s share of joint ventures’ undistributed earnings	27,667,432	23,645,685
EXCOR [Member]
Investments in joint ventures	17,274,991	14,645,783
NTIC’s share of joint ventures’ undistributed earnings	17,244,086	14,614,878
All Other [Member]
Investments in joint ventures	7,419,496	10,751,504
NTIC’s share of joint ventures’ undistributed earnings	6,526,056	9,030,807
Acobal [Member]
Investments in joint ventures	2,619,932
NTIC’s share of joint ventures’ undistributed earnings	2,619,932
Zerust OY [Member]
Investments in joint ventures	1,297,358
NTIC’s share of joint ventures’ undistributed earnings	1,277,358
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Current assets	60,062,085	56,420,503
Total assets	69,815,251	64,183,071
Current liabilities	11,743,525	12,553,716
Non-current liabilities	336,557	323,199
Joint ventures’ equity	57,735,169	51,306,156
EXCOR [Member]
Current assets	29,870,525	26,234,664
Total assets	36,941,008	31,513,288
Current liabilities	2,391,029	2,221,726
Non-current liabilities	0	0
Joint ventures’ equity	34,549,979	29,291,562
Joint Ventures in France [Member]
Current assets		30,185,839
Total assets		32,669,783
Current liabilities		10,331,990
Non-current liabilities		323,199
Joint ventures’ equity		$ 22,014,594
Acobal [Member]
Current assets	6,971,262
Total assets	7,900,298
Current liabilities	2,660,430
Non-current liabilities	0
Joint ventures’ equity	5,239,868
Zerust OY [Member]
Current assets	3,029,614
Total assets	3,313,909
Current liabilities	719,172
Non-current liabilities	0
Joint ventures’ equity	2,594,737
All Other [Member]
Current assets	20,190,684
Total assets	21,660,036
Current liabilities	5,972,894
Non-current liabilities	336,557
Joint ventures’ equity	$ 15,350,585