Note 1 - Interim Financial Information - Schedule of Error Corrections (Details) - USD ($)	3 Months Ended		6 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022	Nov. 30, 2022	Aug. 31, 2022	Nov. 30, 2021	Aug. 31, 2021
Cost of goods sold	$ 11,967,757	$ 11,764,304	$ 25,567,399	$ 24,254,787
Net income	520,068	295,985	1,153,748	5,017,818
Receivables: Trade, excluding joint ventures, less allowance for doubtful accounts of $439,000 as of February 28, 2023	14,101,266		14,101,266			$ 14,136,930
Gross profit	6,303,068	4,984,335	12,656,192	10,687,265
Comprehensive income	1,054,781	322,280	1,634,544	4,635,049
Trade, excluding joint ventures			(338,014)	321,322
Total current assets	39,602,851		39,602,851			40,234,881
Selling expenses	3,595,717	2,971,391	7,103,151	6,209,149
Comprehensive income attributable to NTIC	1,166,739	458,317	1,884,727	4,927,151
Accrued liabilities			(488,221)	(1,715,302)
Total assets	86,136,754		86,136,754			86,193,953
General and administrative expenses	3,134,189	2,518,788	6,264,788	5,115,135
Accrued liabilities: Payroll and related benefits	1,204,717		1,204,717			2,297,543
Research and development expenses	1,141,083	1,218,674	2,397,807	2,454,495
Total current liabilities	16,078,289		16,078,289			17,065,401
Total operating expenses	7,870,989	6,708,853	15,765,746	13,778,779
Retained earnings	50,319,062		50,319,062			50,716,613
Operating income	813,556	445,223	1,643,132	1,711,834
Stockholders’ equity	64,790,600		64,790,600			63,595,262
Income before income tax expense	701,863	447,728	1,446,276	5,673,941
Total equity	68,234,243	69,437,767	68,234,243	69,437,767	$ 67,873,195	67,244,296	$ 69,630,844	$ 65,750,581
Total liabilities and equity	86,136,754		86,136,754			$ 86,193,953
Net income attributable to NTIC	$ 411,497	$ 182,847	$ 913,739	$ 4,676,606
Basic (in dollars per share)	$ 0.04	$ 0.02	$ 0.1	$ 0.51
Diluted (in dollars per share)	$ 0.04	$ 0.02	$ 0.09	$ 0.48
Previously Reported [Member]
Cost of goods sold	$ 11,867,639		$ 25,467,281
Net income	993,819		1,627,499
Receivables: Trade, excluding joint ventures, less allowance for doubtful accounts of $439,000 as of February 28, 2023	14,675,017		14,675,017
Gross profit	6,403,186		12,756,310
Comprehensive income	1,528,532		2,108,295
Trade, excluding joint ventures			(911,765)
Total current assets	40,176,602		40,176,602
Selling expenses	3,418,717		6,926,151
Comprehensive income attributable to NTIC	1,640,490		2,358,478
Accrued liabilities			(388,221)
Total assets	86,710,505		86,710,505
General and administrative expenses	3,084,189		6,214,788
Accrued liabilities: Payroll and related benefits	1,304,717		1,304,717
Research and development expenses	994,450		2,251,174
Total current liabilities	16,178,289		16,178,289
Total operating expenses	7,497,356		15,392,113
Retained earnings	50,792,813		50,792,813
Operating income	1,287,307		2,116,883
Stockholders’ equity	65,264,351		65,264,351
Income before income tax expense	1,175,614		1,920,027
Total equity	68,707,994		68,707,994
Total liabilities and equity	86,710,505		86,710,505
Net income attributable to NTIC	$ 885,248		$ 1,387,490
Basic (in dollars per share)	$ 0.1		$ 0.15
Diluted (in dollars per share)	$ 0.09		$ 0.14
Revision of Prior Period, Adjustment [Member]
Cost of goods sold	$ 100,118		$ 100,118
Net income	(473,751)		(473,751)
Receivables: Trade, excluding joint ventures, less allowance for doubtful accounts of $439,000 as of February 28, 2023	(573,751)		(573,751)
Gross profit	(100,118)		(100,118)
Comprehensive income	(473,751)		(473,751)
Trade, excluding joint ventures			573,751
Total current assets	(573,751)		(573,751)
Selling expenses	177,000		177,000
Comprehensive income attributable to NTIC	(473,751)		(473,751)
Accrued liabilities			(100,000)
Total assets	(573,751)		(573,751)
General and administrative expenses	50,000		50,000
Accrued liabilities: Payroll and related benefits	(100,000)		(100,000)
Research and development expenses	146,633		146,633
Total current liabilities	(100,000)		(100,000)
Total operating expenses	373,633		373,633
Retained earnings	(473,751)		(473,751)
Operating income	(473,751)		(473,751)
Stockholders’ equity	(473,751)		(473,751)
Income before income tax expense	(473,751)		(473,751)
Total equity	(473,751)		(473,751)
Total liabilities and equity	(573,751)		(573,751)
Net income attributable to NTIC	$ (473,751)		$ (473,751)
Basic (in dollars per share)	$ (0.06)		$ 0.05
Diluted (in dollars per share)	$ (0.05)		$ 0.05