Document And Entity Information	9 Months Ended
Document And Entity Information	May 31, 2013	Jul. 12, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	Northern Technologies International Corporation
Document Type	10-Q
Current Fiscal Year End Date	--08-31
Entity Common Stock, Shares Outstanding		4,428,036
Amendment Flag	false
Entity Central Index Key	0000875582
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	May 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3

Consolidated Balance Sheets As of May 31,2013 (Unaudited) and August 31,2012 (USD $)	May 31, 2013	Aug. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 3,176,157	$ 4,137,547
Trade excluding joint ventures, less allowance for doubtful accounts of $20,000 at May 31, 2013 and August 31, 2012	2,801,488	2,516,961
Trade joint ventures	1,120,085	734,543
Fees for services provided to joint ventures	2,459,487	1,316,933
Income taxes	174,092	58,129
Inventories	5,216,976	4,151,197
Prepaid expenses	352,395	548,331
Deferred income taxes	596,085	596,085
Total current assets	15,896,765	14,059,726
PROPERTY AND EQUIPMENT, NET	5,126,133	4,288,618
OTHER ASSETS:
Investments in joint ventures	23,320,080	21,461,492
Deferred income taxes	1,030,610	1,030,610
Patents and trademarks, net	1,061,725	961,181
Other	76,000	76,000
Total other assets	25,488,415	23,529,283
Total assets	46,511,313	41,877,627
CURRENT LIABILITIES:
Current portion of note payable	76,119	76,120
Accounts payable	1,267,591	1,818,309
Accrued liabilities:
Payroll and related benefits	1,055,766	1,565,866
Deferred joint venture royalties	288,000	288,000
Other	72,755	251,350
Total current liabilities	2,760,231	3,999,645
NOTE PAYABLE, NET OF CURRENT PORTION (Note 7)	876,325	933,413
COMMITMENTS AND CONTINGENCIES (Note 13)
EQUITY:
Preferred stock, no par value; authorized 10,000 shares; none issued and outstanding	0	0
Common stock, $0.02 par value per share; authorized 10,000,000 shares; issued and outstanding 4,428,036 and 4,403,656, respectively	88,561	88,073
Additional paid-in capital	11,557,585	11,130,966
Retained earnings	27,011,178	25,260,034
Accumulated other comprehensive income	334,236	277,583
Stockholders’ equity	38,991,560	36,756,656
Non-controlling interest	3,883,197	187,913
Total equity	42,874,757	36,944,569
Total liabilities and equity	$ 46,511,313	$ 41,877,627

Consolidated Balance Sheets As of May 31,2013 (Unaudited) and August 31,2012 (Parentheticals) (USD $)	May 31, 2013	Aug. 31, 2012
Trade, allowance (in Dollars)	$ 20,000	$ 20,000
Preferred stock, par value (in Dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock par value (in Dollars per share)	$ 0.02	$ 0.02
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	4,428,036	4,403,656
Common stock, shares outstanding	4,428,036	4,403,656

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
NET SALES:
Net sales, excluding joint ventures	$ 5,041,096	$ 7,175,825	$ 14,296,686	$ 15,579,086
Net sales, to joint ventures	835,937	629,079	2,118,444	2,032,260
Total net sales	5,877,033	7,804,904	16,415,130	17,611,346
Cost of goods sold	4,054,364	4,143,514	11,379,249	10,833,072
Gross profit	1,822,669	3,661,390	4,935,881	6,778,274
JOINT VENTURE OPERATIONS:
Equity in income of joint ventures	1,440,335	1,822,972	3,733,069	4,405,327
Fees for services provided to joint ventures	1,917,947	734,337	5,535,105	3,477,715
Total joint venture operations	3,358,282	2,557,309	9,268,174	7,883,042
OPERATING EXPENSES:
Selling expenses	1,243,687	1,270,996	3,588,847	3,393,564
General and administrative expenses	1,105,710	1,147,744	3,498,393	3,518,569
Expenses incurred in support of joint ventures	335,132	294,169	1,026,275	729,990
Research and development expenses	1,002,651	1,067,454	2,853,250	2,856,536
Total operating expenses	3,687,180	3,780,363	10,966,765	10,498,659
OPERATING INCOME	1,493,771	2,438,336	3,337,290	4,162,657
INTEREST INCOME	2,984	15,726	50,618	36,417
INTEREST EXPENSE	(50,986)	(6,264)	(64,448)	(19,514)
OTHER INCOME		6,825		20,475
INCOME BEFORE INCOME TAX EXPENSE	1,445,769	2,454,623	3,323,460	4,200,035
INCOME TAX EXPENSE	158,000	814,000	532,000	1,020,000
NET INCOME	1,287,769	1,640,623	2,791,460	3,180,035
NET INCOME ATTRIBUTABLE TO NON CONTROLLING INTEREST	360,657	186,586	1,040,316	161,048
NET INCOME ATTRIBUTABLE TO NTIC	$ 927,112	$ 1,454,037	$ 1,751,144	$ 3,018,987
NET INCOME PER COMMON SHARE:
Basic (in Dollars per share)	$ 0.21	$ 0.33	$ 0.40	$ 0.69
Diluted (in Dollars per share)	$ 0.21	$ 0.33	$ 0.39	$ 0.68
WEIGHTED AVERAGE COMMON SHARES ASSUMED OUTSTANDING:
Basic (in Shares)	4,421,379	4,399,290	4,415,452	4,379,175
Diluted (in Shares)	4,468,861	4,461,044	4,464,774	4,448,472

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
NET INCOME	$ 1,287,769	$ 1,640,623	$ 2,791,460	$ 3,180,035
OTHER COMPREHENSIVE INCOME (LOSS) – FOREIGN CURRENCY TRANSLATION ADJUSTMENT	(292,001)	(1,346,222)	103,543	(2,600,098)
COMPREHENSIVE INCOME (LOSS)	995,768	294,401	2,895,003	579,937
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO NONCONTROLLING INTERESTS	352,519	156,450	1,087,206	123,608
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO STOCKHOLDERS	$ 643,249	$ 137,951	$ 1,807,797	$ 456,329

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	May 31, 2013	May 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,791,460	$ 3,180,035
Adjustments to reconcile net income to net cash used in operating activities:
Expensing of fair value of stock options vested	213,347	216,712
Depreciation expense	316,118	255,641
Amortization expense	53,264	113,624
Loss on disposal of assets	13,842
Equity in income from joint ventures	(3,733,069)	(4,405,327)
Receivables:
Trade, excluding joint ventures	(306,554)	(341,903)
Trade, joint ventures	(385,542)	41,562
Fees for services receivables, joint ventures	199,532	199,871
Income taxes	(116,816)	(6,403)
Inventories	(1,085,743)	(117,023)
Prepaid expenses and other	195,848	(539,868)
Accounts payable	(526,505)	(479,801)
Income tax payable	2,783	138,132
Accrued liabilities	(684,857)	571,824
Net cash used in operating activities	(3,052,892)	(1,172,924)
CASH FLOWS FROM INVESTING ACTIVITIES:
Dividends received from joint ventures	3,017,586	3,045,544
Additions to property and equipment	(1,160,344)	(402,620)
Effect of NTI Asean consolidation on cash (Note 2)	1,612,768
Additions to patents	(167,652)	(125,555)
Net cash provided by investing activities	3,302,358	2,517,369
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of note payable	(57,089)	(57,089)
Dividend received by non-controlling interest	(1,352,841)
Proceeds from employee stock purchase plan	56,739	55,410
Proceeds from exercise of stock options	157,021	15,040
Net cash (used in) provided by financing activities	(1,196,170)	13,361
EFFECT OF EXCHANGE RATE CHANGES ON CASH:	(14,686)	(158,270)
NET INCREASE IN CASH AND CASH EQUIVALENTS	(961,390)	1,199,536
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	4,137,547	3,266,362
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 3,176,157	$ 4,465,898

Note 1 - Interim Financial Information

9 Months Ended

May 31, 2013

Disclosure Text Block [Abstract]

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

1.	INTERIM FINANCIAL INFORMATION

In the opinion of management, the accompanying unaudited consolidated financial statements contain all necessary adjustments, which are of a normal recurring nature, and present fairly the consolidated financial position of Northern Technologies International Corporation and its subsidiaries (the Company) as of May 31, 2013 and August 31, 2012 and the results of their operations for the three and nine months ended May 31, 2013 and 2012 and their cash flows for the nine months ended May 31, 2013 and 2012, in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP).

Certain amounts reported in the consolidated financial statements for the previous reporting periods have been reclassified to conform to the current period presentation. These reclassifications did not have a material impact on the Company’s previously reported consolidated balance sheets or statements of cash flows.

These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s annual report on Form 10-K for the fiscal year ended August 31, 2012. These consolidated financial statements also should be read in conjunction with the “Management’s Discussion and Analysis of Financial Condition and Results of Operations” section appearing in this report.

Operating results for the three and nine months ended May 31, 2013 are not necessarily indicative of the results that may be expected for the full fiscal year ending August 31, 2013.

The Company evaluates events occurring after the date of the consolidated financial statements requiring recording or disclosure in the consolidated financial statements.

Note 2 - NTI ASEAN

9 Months Ended

May 31, 2013

Business Combination Disclosure [Text Block]

Business Combination Disclosure [Text Block]

NTI ASEAN

NTI Asean LLC (NTI Asean) is an entity that holds investments in eight entities operating in the Association of Southeast Asian Nations (ASEAN) region, including the following countries: China, Indonesia, Korea, Malaysia, Philippines, Singapore, Taiwan and Thailand.

Prior to September 1, 2012, the Company owned 50% of NTI Asean, which it considered to be less than a majority, of the equity and voting rights and accounted for its investment using the equity method. On September 1, 2012, the Company obtained an additional 10% ownership interest in NTI Asean in exchange for a license agreement, and thereafter holds 60% of the equity and voting rights of NTI Asean.

The Company accounted for the transaction resulting in the additional ownership as a business combination. Beginning in the first quarter of fiscal 2013, the Company consolidated the results of NTI Asean. Immediately prior to the transaction, the Company re-measured the fair value of NTI Asean and determined that there was no difference between the fair value and the book value of the entity. As a result, there was no accounting impact related to the business combination in the consolidated statements of operations.

The Company determined the fair value of NTI Asean using the capitalized income method, including a capitalization rate of 25%. The allocation of the total transaction amount was as follow:

Net assets acquired (liabilities assumed):
Cash and cash equivalents	$	1,613,000
Accounts receivables		1,342,000
Investments in joint ventures		4,967,000
Value of assets	$	7,922,000

Purchase price:
Fair value of non-controlling interest	$	3,961,000
Value of previously held interest		3,961,000
Total consideration	$	7,922,000

The following is a summary of certain line items of the Company’s consolidated statement of operations for the three months ended May 31, 2012 as reported and on a pro forma basis, assuming the consolidation of NTI Asean on the Company’s consolidated financial statements as of the beginning of such period:

	As Reported		NTI Asean			Eliminated in Consolidation			Pro Forma
Net sales	$	7,804,904	$	—		$	—		$	7,804,904
Cost of goods sold		4,143,514		—			—			4,143,514
Gross profit		3,661,390		—			—			3,661,390
Joint venture operations		2,557,309		870,663			(384,115	)		3,043,857
Operating expenses		3,780,363		110,637			—			3,891,000
Operating income		2,438,336		760,026			(384,115	)		2,814,247
Income before income tax expense		2,454,623		760,026			(384,115	)		2,830,534
Income tax expense		814,000		99,208			—			913,208
Net income		1,640,623		660,818			(384,115	)		1,917,326
Net income attributable to non-controlling interest		186,586		(264,327	)		—			(77,741	)
Net income attributable to NTIC		1,454,037		396,491			(384,115	)		1,466,413
Net income per common diluted share	$	0.33	$	0.09		$	(0.09	)	$	0.33

The following is a summary of certain line items of the Company’s consolidated statements of operations for the nine months ended May 31, 2012 as reported and on a pro forma basis, assuming the consolidation of NTI Asean on the Company’s consolidated financial statements as of the beginning of such period:

	As Reported		NTI Asean			Eliminated in Consolidation			Pro Forma
Net sales	$	17,611,346	$	—		$	—		$	17,611,346
Cost of goods sold		10,833,072		—			—			10,833,072
Gross profit		6,778,274		—			—			6,778,274
Joint venture operations		7,883,042		2,569,943			(1,076,230	)		9,376,755
Operating expenses		10,498,659		133,772			—			10,632,431
Operating income		4,162,657		2,436,171			(1,076,230	)		5,522,598
Income before income tax expense		4,200,035		2,436,171			(1,076,230	)		5,559,976
Income tax expense		1,020,000		284,019			—			1,304,019
Net income		3,180,035		2,152,152			(1,076,230	)		4,255,957
Net income attributable to non-controlling interest		161,048		(860,861	)		—			(699,813	)
Net income attributable to NTIC		3,018,987		1,291,291			(1,076,230	)		3,234,048
Net income per common diluted share	$	0.68	$	0.29		$	(0.24	)	$	0.73

Note 4 - Property and Equipment, Net

9 Months Ended

May 31, 2013

Property, Plant and Equipment Disclosure [Text Block]

Property, Plant and Equipment Disclosure [Text Block]

4.	PROPERTY AND EQUIPMENT, NET

Property and equipment, net consisted of the following:

	May 31, 2013			August 31, 2012
Land	$	310,365		$	310,365
Buildings and improvements		4,302,151			3,406,674
Machinery and equipment		3,173,684			2,908,021
		7,786,200			6,625,060
Less accumulated depreciation		(2,660,067	)		(2,336,442	)
	$	5,126,133		$	4,288,618

Note 5 - Patents and Trademarks, Net

9 Months Ended

May 31, 2013

Disclosure Text Block [Abstract]

Intangible Assets Disclosure [Text Block]

5.	PATENTS AND TRADEMARKS, NET

Patents and trademarks, net consisted of the following:

	May 31, 2013			August 31, 2012
Patents and trademarks	$	2,097,872		$	1,945,785
Less accumulated amortization		(1,036,147	)		(984,604	)
	$	1,061,725		$	961,181

Patent and trademark costs are amortized over seven years. Costs incurred related to patents and trademarks are capitalized until filed and approved, at which time the amounts capitalized to date are amortized and any further costs, including maintenance costs, are expensed as incurred. Amortization expense is estimated to approximate $80,000 in each of the next five fiscal years.

Note 6 - Investments in Joint Ventures

9 Months Ended

May 31, 2013

Equity Method Investments and Joint Ventures Disclosure [Text Block]

Equity Method Investments and Joint Ventures Disclosure [Text Block]

6.	INVESTMENTS IN JOINT VENTURES

The financial statements of the Company’s foreign joint ventures are initially prepared using the accounting principles accepted in the respective joint ventures’ countries of domicile. Amounts related to foreign joint ventures reported in the below tables and the accompanying consolidated financial statements have subsequently been adjusted to approximate U.S. GAAP in all material respects. All material profits recorded on sales from the Company to its joint ventures of goods that remain in inventory, have been eliminated for financial reporting purposes.

Financial information from the audited and unaudited financial statements of the Company’s joint venture in Germany, Excor Korrosionsschutz – Technologien und Produkte GmbH (EXCOR), China, NTI Asean and all of the Company’s other joint ventures, are summarized as follows:

	At May 31, 2013
	Total		EXCOR		China		All Other
Current assets	$	63,547,204	$	23,056,084	$	13,964,465	$	26,526,655
Total assets		69,688,319		25,425,172		13,993,902		30,269,245
Current liabilities		19,288,471		3,056,560		6,212,433		10,019,478
Noncurrent liabilities		3,358,593		—		869,532		2,489,061
Joint ventures’ equity		47,041,255		22,368,612		6,911,937		17,760,706
Northern Technologies International Corporation’s share of joint ventures’ equity		23,320,080		11,184,308		3,455,969		8,679,803
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	20,877,265	$	11,153,403	$	3,405,969	$	6,327,893

	At August 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Current assets	$	61,973,725	$	24,357,139	$	15,358,967	$	22,257,619
Total assets		68,585,974		26,620,589		15,522,456		26,442,929
Current liabilities		18,686,181		4,749,574		5,763,857		8,172,750
Noncurrent liabilities		4,700,458		—		1,055,965		3,644,493
Joint ventures’ equity		45,199,335		21,871,015		8,702,634		14,625,686
Northern Technologies International Corporation’s share of joint ventures’ equity		21,461,492		10,935,509	$	3,685,404		6,840,579
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	19,403,150	$	10,904,604	$	3,314,445	$	5,184,101

	Nine Months Ended May 31, 2013
	Total		EXCOR		China		All Other
Net sales	$	82,788,711	$	26,043,775	$	10,802,206	$	45,942,730
Gross profit		39,447,084		13,624,792		5,134,820		20,687,472
Net income		7,626,711		4,954,595		815,664		1,856,452
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	3,733,069	$	2,478,109	$	407,809	$	847,151

	Nine Months Ended May 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Net sales	$	83,746,872	$	25,785,840	$	16,366,258	$	41,594,775
Gross profit		40,201,265		13,423,067		7,183,786		19,594,413
Net income		8,165,791		4,830,477		1,941,417		1,393,897
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	4,405,327	$	2,396,596	$	1,076,230	$	932,501

*Prior to September 1, 2012, the Company owned 50% of NTI Asean, which included the joint venture in China, and disclosed its financial information accordingly. On September 1, 2012, the Company obtained an additional 10% ownership interest in NTI Asean and has consolidated the results of NTI Asean subsequent to that date. As a result the Company now discloses the financial information for only its joint venture in China and not all of NTI Asean accordingly.

The Company records expenses that are directly attributable to the joint ventures on the consolidated statements of operations on the line “Expenses incurred in support of joint ventures”. The expenses include items such as employee compensation and benefit expenses, travel expense and consulting expense.

The Company did not make any joint venture investments during the nine months ended May 31, 2013 and 2012.

Note 7 - Corporate Debt

9 Months Ended

May 31, 2013

Debt Disclosure [Text Block]

Debt Disclosure [Text Block]

7.	CORPORATE DEBT

As of May 31, 2013, Northern Technologies Holding Company, LLC (NTI LLC) had a term loan with a principal amount of $952,444 outstanding that NTI LLC obtained from PNC Bank, National Association (PNC Bank) in connection with the purchase of NTIC’s corporate headquarters in September 2006. The term loan matures on January 10, 2016, bears interest at an annual rate based on the daily LIBOR rate plus 2.15% and is payable in consecutive monthly installments equal to approximately $6,343 (inclusive of principal but exclusive of interest). The term loan is secured by a first lien on the real estate and building owned by NTI LLC and all of the assets of the Company and is guaranteed by the Company.

The Company has a revolving line of credit with PNC Bank of $3,000,000. No amounts were outstanding under the line of credit as of May 31, 2013 and August 31, 2012. At the option of the Company, outstanding advances under the line of credit bear interest at either (a) an annual rate based on LIBOR plus 2.15% for the applicable LIBOR interest period selected by the Company or (b) at the rate publicly announced by PNC Bank from time to time as its prime rate. Interest is payable in arrears (a) for the portion of advances bearing interest under the prime rate on the last day of each month during the term thereof and (b) for the portion of advances bearing interest under the LIBOR option on the last day of the respective LIBOR interest period selected for such advance. Any unpaid interest is payable on the maturity date. As of May 31, 2013, the interest rate was 2.85% and the weighted average rate was 3.02% for the nine months ended May 31, 2013. As of May 31, 2012, the interest rate was 3.20% and the weighted average rate was 3.16% for the nine months ended May 31, 2012. The revolving line of credit is secured by cash, receivables and inventory.

The term loan and the line of credit are governed under separate loan agreements (collectively, the Loan Agreements). The Loan Agreements contain standard covenants, including affirmative financial covenants, such as the maintenance of a minimum fixed charge coverage ratio, and negative covenants, which, among other things, limit the incurrence of additional indebtedness, loans and equity investments, disposition of assets, mergers and consolidations and other matters customarily restricted in such agreements. Under the Loan Agreements, the Company is subject to a minimum fixed charge coverage ratio of 1.10:1.00. As of May 31, 2013, the Company was in compliance with all debt covenants.

On December 11, 2012, PNC Bank extended the maturity date of the line of credit from January 9, 2013 to January 8, 2014, and waived a technical covenant default by the Company to deliver quarterly compliance certificates. All other terms of the line of credit and the loan agreement and other documents evidencing the line of credit remain the same. It is anticipated that the line of credit will be extended again prior to the January 8, 2014 maturity date.

Note 8 - Stockholders' Equity

9 Months Ended

May 31, 2013

Stockholders' Equity Note Disclosure [Text Block]

Stockholders' Equity Note Disclosure [Text Block]

8.	STOCKHOLDERS’ EQUITY

During the nine months ended May 31, 2013, the Company did not purchase or retire any shares of its common stock. The following stock options to purchase shares of common stock were exercised during the nine months ended May 31, 2013:

Options Exercised	Exercise Price
25,140	$	9.95
4,000		8.57
1,734		7.65
1,500		9.76
666		7.75

The Company granted stock options under the Northern Technologies International Corporation Amended and Restated 2007 Stock Incentive Plan (the 2007 Plan) to purchase an aggregate of 118,294 shares of its common stock to various employees and directors during the nine months ended May 31, 2013. The weighted average per share exercise price of the stock options is $10.25, which is equal to the fair market value of the Company’s common stock on the date of grant.

During the nine months ended May 31, 2012, the Company did not purchase or retire any shares of its common stock. The following stock options to purchase shares of common stock were exercised during the nine months ended May 31, 2012:

	Options Exercised		Exercise Price
	1,966		$	7.65

The Company granted stock options under the 2007 Plan to purchase an aggregate of 26,000 shares of its common stock to various employees and directors during the nine months ended May 31, 2012. The weighted average per share exercise price of the stock options is $16.45, which is equal to the fair market value of the Company’s common stock on the date of grant.

During the nine months ended May 31, 2012, the Company issued stock bonuses under the 2007 Plan for an aggregate of 42,707 shares of its common stock to various employees at a grant price of $14.42 per share. The aggregate fair value of the shares of the Company’s common stock as of the date of payment of the stock bonuses was $615,830, based on the closing sale price of a share of the Company’s common stock on the date of payment. The fair value of common stock granted during the nine months ended May 31, 2012 was based on fiscal 2012 performance and was included in accrued liabilities at August 31, 2012.

Note 9 - Net Income Per Common Share

9 Months Ended

May 31, 2013

Earnings Per Share [Text Block]

Earnings Per Share [Text Block]

9.	NET INCOME PER COMMON SHARE

Basic net income per common share is computed by dividing net income by the weighted average number of common shares outstanding. Diluted net income per share assumes the exercise of stock options using the treasury stock method, if dilutive.

Options to purchase shares of common stock of 40,000 were excluded from the computation of common share equivalents for the three and nine months ended May 31, 2013, as the exercise prices of such options were greater than market price of a share of common stock. Options to purchase shares of common stock of 26,000 were excluded from the computation of common share equivalents for the three and nine months ended May 31, 2012, as the exercise prices of such options were greater than market price of a share of common stock.

The following is a reconciliation of the earnings per share computation for the three and nine months ended May 31, 2013 and 2012:

	Three Months Ended				Nine Months Ended
Numerators:	May 31, 2013		May 31, 2012		May 31, 2013		May 31, 2012
Net income attributable to NTIC	$	927,112	$	1,454,037	$	1,751,144	$	3,018,987

Denominator:
Basic – weighted shares outstanding		4,421,379		4,399,290		4,415,452		4,379,175
Weighted shares assumed upon exercise of stock options		47,482		61,754		49,322		65,297
Diluted – weighted shares outstanding		4,468,861		4,461,044		4,464,774		4,448,472
Basic earnings per share:	$	0.21	$	0.33	$	0.40	$	0.69
Diluted earnings per share:	$	0.21	$	0.33	$	0.39	$	0.68

The dilutive impact summarized above relates to the periods when the average market price of the Company’s common stock exceeded the exercise price of the potentially dilutive option securities granted. Earnings per common share were based on the weighted average number of common shares outstanding during the periods when computing the basic earnings per share. When dilutive, stock options are included as equivalents using the treasury stock market method when computing the diluted earnings per share.

Note 10 - Stock-Based Compensation

9 Months Ended

May 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

10.	STOCK-BASED COMPENSATION

The Company has two stock-based compensation plans under which stock options and other stock-based awards have been granted, including the Northern Technologies International Corporation Amended and Restated 2007 Stock Incentive Plan and the Northern Technologies International Corporation Employee Stock Purchase Plan (the ESPP). The Compensation Committee of the Board of Directors and the Board of Directors administers these plans.

The 2007 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, stock unit awards, performance awards and stock bonuses to eligible recipients to enable the Company and its subsidiaries to attract and retain qualified individuals through opportunities for equity participation in the Company, and to reward those individuals who contribute to the achievement of the Company’s economic objectives. Subject to adjustment as provided in the 2007 Plan, up to a maximum of 800,000 shares of the Company’s common stock are issuable under the 2007 Plan. Options granted under the 2007 Plan generally have a term of five years and become exercisable over a three- or four-year period beginning on the one-year anniversary of the date of grant. Options are granted at per share exercise prices equal to the market value of the Company’s common stock on the date of grant. To date, only stock options and stock bonuses have been granted under the 2007 Plan.

The maximum number of shares of common stock of the Company available for issuance under the ESPP is 100,000 shares, subject to adjustment as provided in the ESPP. The ESPP provides for six-month offering periods beginning on September 1 and March 1 of each year. The purchase price of the shares is 90% of the lower of the fair market value of common stock at the beginning or end of the offering period. This discount may not exceed the maximum discount rate permitted for plans of this type under Section 423 of the Internal Revenue Code of 1986, as amended. The ESPP is compensatory for financial reporting purposes.

The Company granted options to purchase an aggregate of 118,294 and 26,000 shares of its common stock during the nine months ended May 31, 2013 and 2012, respectively. The fair value of option grants is determined at date of grant, using the Black-Scholes option pricing model with the assumptions listed below. Based on these valuations, the Company recognized compensation expense of $213,374 and $216,712 during the nine months ended May 31, 2013 and 2012, respectively, related to the options that vested during such time period. The stock-based expense recorded reduced after-tax net income per share by $0.05 for each of the nine months ended May 31, 2013 and 2012. As of May 31, 2013, the total compensation cost for non-vested options not yet recognized in the Company’s consolidated statements of operations was $398,849 net of estimated forfeitures. Additional stock-based compensation expense of $93,077 is expected through the remainder of fiscal year 2013, and expense of $185,815 and $99,964 is expected to be recognized during fiscal 2014 and fiscal 2015, respectively. Future option grants will impact the compensation expense recognized.

The Company currently estimates a ten percent forfeiture rate for stock options and continually reviews this estimate for future periods.

The fair value of each option grant is estimated on the grant date using the Black-Scholes option-pricing model with the following assumptions and results for the grants:

	May 31,
	2013			2012
Dividend yield			0.00%	0.00%
Expected volatility			48.0%	48.8%
Expected life of option (years)	5	-	10	5
Average risk-free interest rate			0.71%	1.31%

The weighted average per share fair value of options granted during nine months ended May 31, 2013 and 2012 was $5.53 and $7.14, respectively. The weighted average remaining contractual life of the options outstanding as of May 31, 2013 and 2012 was 4.48 years and 1.82 years, respectively.

Note 11 - Geographic And Segment Information

9 Months Ended

May 31, 2013

Segment Reporting Disclosure [Text Block]

Segment Reporting Disclosure [Text Block]

11.	GEOGRAPHIC AND SEGMENT INFORMATION

Net sales by geographic location as a percentage of total consolidated net sales for the three and nine months ended May 31, 2013 and 2012 were as follows:

	Three Months Ended						Nine Months Ended
	May 31, 2013			May 31, 2012			May 31, 2013			May 31, 2012
Inside the U.S.A. to unaffiliated customers		69.8	%		58.0	%		68.9	%		61.2	%
Outside the U.S.A to:
Joint ventures in which the Company is a shareholder directly and indirectly		11.1	%		10.9	%		14.9	%		12.6	%
Unaffiliated customers		19.1	%		31.1	%		16.2	%		26.2	%
		100.0	%		100.0	%		100.0	%		100.0	%

Net sales by geographic location are based on the location of the customer.

Fees for services provided to joint ventures by geographic location as a percentage of total fees for services provided to joint ventures during the three and nine months ended May 31, 2013 and 2012 were as follows:

	Three Months Ended
	May 31, 2013		% of Total Fees for Services Provided to Joint Ventures			May 31, 2012			% of Total Fees for Services Provided to Joint Ventures
China*	$	524,724		27.3	%	$	—			0.0	%
Germany		250,000		13.0	%		241,338			32.9	%
Japan		177,432		9.3	%		260,026			35.4	%
Thailand*		169,085		8.8	%		—			0.0	%
Korea**		147,867		7.7	%		61,152			8.4	%
Sweden		141,000		7.4	%		141,257			19.2	%
Poland		113,339		5.9	%		113,305			15.4	%
France		104,645		5.5	%		128,480			17.5	%
Finland		85,246		4.4	%		127,344			17.3	%
United Kingdom		65,193		3.4	%		83,879			11.4	%
India		—		0.0	%		(492,602	)		(67.1	)%
Other		139,416		7.3	%		70,158			9.6	%
	$	1,917,947		100.0	%	$	734,337			100.0	%

*	Joint venture owned by NTI Asean.

**	Joint venture owned by NTI Asean as of May 31, 2013, but not as of May 31, 2012. NTI Asean results are not included on the consolidated financial statements for the three months ended May 31, 2012. (See Note 2)

	Nine Months Ended
	May 31, 2013		% of Total Fees for Services Provided to Joint Ventures			May 31, 2012			% of Total Fees for Services Provided to Joint Ventures
China*	$	1,468,622		26.5	%	$	—			0.0	%
Germany		742,213		13.4	%		742,171			21.3	%
Japan		548,618		9.9	%		763,548			22.0	%
Thailand*		471,074		8.5	%		—			0.0	%
Korea**		409,997		7.4	%		138,149			4.0	%
France		381,043		6.9	%		397,123			11.4	%
Poland		379,650		6.9	%		341,603			9.8	%
Sweden		305,619		5.5	%		446,191			12.8	%
Finland		245,426		4.4	%		378,751			10.9	%
United Kingdom		168,005		3.1	%		244,017			7.0	%
India		—		0.0	%		(192,758	)		(5.5	)%
Other		414,838		7.5	%		218,920			6.3	%
	$	5,535,105		100.0	%	$	3,477,715			100.0	%

*	Joint venture owned by NTI Asean.

**	Joint venture owned by NTI Asean as of May 31, 2013, but not as of May 31, 2012. NTI Asean results are not included on the consolidated financial statements for the nine months ended May 31, 2012. (See Note 2)

The following table sets forth the Company’s net sales for the three and nine months ended May 31, 2013 and 2012 by segment:

	Three Months Ended				Nine Months Ended
	May 31, 2013		May 31, 2012		May 31, 2013		May 31, 2012
ZERUST® sales	$	5,418,271	$	7,220,258	$	14,923,966	$	16,243,683
Natur-Tec™ sales		458,762		584,646		1,491,164		1,367,663
	$	5,877,033	$	7,804,904	$	16,415,130	$	17,611,346

The following table sets forth the Company’s cost of goods sold for the three and nine months ended May 31, 2013 and 2012 by segment:

	Three Months Ended										Nine Months Ended
	May 31, 2013		% of Product Sales*			May 31, 2012		% of Product Sales*			May 31, 2013		% of Product Sales*			May 31, 2012		% of Product Sales*
Direct cost of goods sold
ZERUST®	$	3,115,980		57.5	%	$	3,046,644		42.2	%	$	8,383,345		56.2	%	$	8,074,031		49.7	%
Natur-Tec®		367,485		80.1	%		501,749		85.8	%		1,260,305		84.5	%		1,160,014		84.8	%
Indirect cost of goods sold		570,899		—			595,121		—			1,735,599		—			1,599,027		—
Total net cost of goods sold	$	4,054,364				$	4,143,514				$	11,379,249				$	10,833,072

*	The percent of segment sales is calculated by dividing the direct cost of goods sold for each individual segment category by the net sales for each segment category.

The Company’s management utilizes product net sales and direct and indirect cost of goods sold for each product in reviewing the financial performance of a product type. Further allocation of Company expenses or assets, aside from amounts presented in the tables above, is not utilized in evaluating product performance, nor does such allocation occur for internal financial reporting.

Sales to the Company’s joint ventures are included in the foregoing geographic and segment information, however, sales by the Company’s joint ventures to other parties are not included. The foregoing geographic and segment information represents only sales and cost of goods sold recognized directly by the Company.

The geographical distribution of key financial statement data is as follows:

	At May 31, 2013
	Brazil		North America		Total
Total assets	$	1,308,385	$	45,202,928	$	46,511,313

	At August 31, 2012
	Brazil		North America		Total
Total assets	$	1,744,693	$	40,132,934	$	41,877,627

	Nine Months Ended May 31, 2013
	Brazil			North America		Total
Net sales	$	1,699,084		$	14,716,046	$	16,415,130
Operating income	$	(263,353	)	$	3,600,643	$	3,337,290

	Nine Months Ended May 31, 2012
	Brazil		North America		Total
Net sales	$	4,004,399	$	13,606,947	$	17,611,346
Operating income	$	1,780,269	$	2,382,388	$	4,162,657

Total assets located in Brazil primarily consist of cash and cash equivalents, customer receivables and inventory. These assets are periodically reviewed to assure the net realizable value from the estimated future production based on forecasted sales exceeds the carrying value of the assets.

Note 12 - Research and Development

9 Months Ended

May 31, 2013

Research, Development, and Computer Software Disclosure [Text Block]

Research, Development, and Computer Software Disclosure [Text Block]

12.	RESEARCH AND DEVELOPMENT

The Company expenses all costs related to product research and development as incurred. The Company incurred $2,853,250 and $2,856,536 of expense during the nine months ended May 31, 2013 and 2012, respectively, in connection with its research and development activities. These costs related to product research and development are net of reimbursements related to certain research and development contracts of $206,046 and $297,258 for the nine months ended May 31, 2013 and 2012, respectively. The net fees are accounted for in the “Research and Development Expenses” section of the consolidated statements of operations.

The Company has certain research and development contracts. The Company accrues proceeds received under such contracts and offsets research and development expenses incurred in equal installments over the timelines associated with completion of the contracts’ specific objectives and milestones. At May 31, 2013, the Company had $143,395 as a receivable, and as of August 31, 2012, the Company had $96,861 of deferred amounts in other accrued liabilities as the Company had not yet performed under the obligations of the contract at that time.

Note 13 - Commitments and Contingencies

9 Months Ended

May 31, 2013

Commitments and Contingencies Disclosure [Text Block]

Commitments and Contingencies Disclosure [Text Block]

13.	COMMITMENTS AND CONTINGENCIES

On August 31, 2012, the Board of Directors of the Company, upon recommendation of the Compensation Committee of the Board of Directors, approved the material terms of an annual bonus plan for the Company’s executive officers and certain officers and employees for the fiscal year ending August 31, 2013. For fiscal 2013 as in past years, the total amount available under the bonus plan will be up to 25% of the Company’s earnings before interest, taxes and other income, as adjusted to take into account amounts to be paid under the bonus plan and certain other adjustments (Adjusted EBITOI), assuming the achievement of at least a minimum Adjusted EBITOI, which is traditionally 70% of a budgeted target Adjusted EBITOI for fiscal 2013, as proposed by the Compensation Committee and approved by the Board of Directors annually. For each plan participant, 50% of the amount of the participant’s individual bonus payout will be determined based upon the participant’s individual allocation percentage of the total amount available under the bonus plan and 50% of the participant’s payout will be determined based upon the participant’s achievement of certain pre-established but more qualitative individual performance objectives. The payment of bonuses under the plan are discretionary and may be paid to executive officer participants in both cash and shares of NTIC common stock, the exact amount and percentages of which will be determined by the Company’s Board of Directors, upon recommendation of the Compensation Committee, after the completion of the Company’s consolidated financial statements for fiscal 2013. There was $580,000 for management bonuses accrued for nine months ended May 31, 2013 compared to a management bonus accrual of $1,058,045 for the nine months ended May 31, 2012.

The Company leases property with future lease payments as follows: fiscal 2013 - $59,625; fiscal 2014 - $59,500 and thereafter - $0.

Three joint ventures accounted for 67.1% and 55.3% of the Company’s trade joint venture receivables at May 31, 2013 and August 31, 2012, respectively.

From time to time, the Company is subject to various claims and legal actions in the ordinary course of its business. The Company is not currently involved in any legal proceeding in which the Company believes, based on information currently available, that there is a reasonable possibility of a material loss.

Note 2 - NTI ASEAN (Tables)

9 Months Ended

May 31, 2013

Business Combination Disclosure [Text Block]

Schedule of Business Acquisitions, by Acquisition [Table Text Block]

Net assets acquired (liabilities assumed):
Cash and cash equivalents	$	1,613,000
Accounts receivables		1,342,000
Investments in joint ventures		4,967,000
Value of assets	$	7,922,000

Purchase price:
Fair value of non-controlling interest	$	3,961,000
Value of previously held interest		3,961,000
Total consideration	$	7,922,000

Business Acquisition, Pro Forma Information [Table Text Block]

	As Reported		NTI Asean			Eliminated in Consolidation			Pro Forma
Net sales	$	7,804,904	$	—		$	—		$	7,804,904
Cost of goods sold		4,143,514		—			—			4,143,514
Gross profit		3,661,390		—			—			3,661,390
Joint venture operations		2,557,309		870,663			(384,115	)		3,043,857
Operating expenses		3,780,363		110,637			—			3,891,000
Operating income		2,438,336		760,026			(384,115	)		2,814,247
Income before income tax expense		2,454,623		760,026			(384,115	)		2,830,534
Income tax expense		814,000		99,208			—			913,208
Net income		1,640,623		660,818			(384,115	)		1,917,326
Net income attributable to non-controlling interest		186,586		(264,327	)		—			(77,741	)
Net income attributable to NTIC		1,454,037		396,491			(384,115	)		1,466,413
Net income per common diluted share	$	0.33	$	0.09		$	(0.09	)	$	0.33

	As Reported		NTI Asean			Eliminated in Consolidation			Pro Forma
Net sales	$	17,611,346	$	—		$	—		$	17,611,346
Cost of goods sold		10,833,072		—			—			10,833,072
Gross profit		6,778,274		—			—			6,778,274
Joint venture operations		7,883,042		2,569,943			(1,076,230	)		9,376,755
Operating expenses		10,498,659		133,772			—			10,632,431
Operating income		4,162,657		2,436,171			(1,076,230	)		5,522,598
Income before income tax expense		4,200,035		2,436,171			(1,076,230	)		5,559,976
Income tax expense		1,020,000		284,019			—			1,304,019
Net income		3,180,035		2,152,152			(1,076,230	)		4,255,957
Net income attributable to non-controlling interest		161,048		(860,861	)		—			(699,813	)
Net income attributable to NTIC		3,018,987		1,291,291			(1,076,230	)		3,234,048
Net income per common diluted share	$	0.68	$	0.29		$	(0.24	)	$	0.73

Note 6 - Investments in Joint Ventures (Tables)

9 Months Ended

May 31, 2013

Equity Method Investments and Joint Ventures Disclosure [Text Block]

Condensed Balance Sheet [Table Text Block]

	At May 31, 2013
	Total		EXCOR		China		All Other
Current assets	$	63,547,204	$	23,056,084	$	13,964,465	$	26,526,655
Total assets		69,688,319		25,425,172		13,993,902		30,269,245
Current liabilities		19,288,471		3,056,560		6,212,433		10,019,478
Noncurrent liabilities		3,358,593		—		869,532		2,489,061
Joint ventures’ equity		47,041,255		22,368,612		6,911,937		17,760,706
Northern Technologies International Corporation’s share of joint ventures’ equity		23,320,080		11,184,308		3,455,969		8,679,803
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	20,877,265	$	11,153,403	$	3,405,969	$	6,327,893

	At August 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Current assets	$	61,973,725	$	24,357,139	$	15,358,967	$	22,257,619
Total assets		68,585,974		26,620,589		15,522,456		26,442,929
Current liabilities		18,686,181		4,749,574		5,763,857		8,172,750
Noncurrent liabilities		4,700,458		—		1,055,965		3,644,493
Joint ventures’ equity		45,199,335		21,871,015		8,702,634		14,625,686
Northern Technologies International Corporation’s share of joint ventures’ equity		21,461,492		10,935,509	$	3,685,404		6,840,579
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	19,403,150	$	10,904,604	$	3,314,445	$	5,184,101

Condensed Income Statement [Table Text Block]

	Nine Months Ended May 31, 2013
	Total		EXCOR		China		All Other
Net sales	$	82,788,711	$	26,043,775	$	10,802,206	$	45,942,730
Gross profit		39,447,084		13,624,792		5,134,820		20,687,472
Net income		7,626,711		4,954,595		815,664		1,856,452
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	3,733,069	$	2,478,109	$	407,809	$	847,151

	Nine Months Ended May 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Net sales	$	83,746,872	$	25,785,840	$	16,366,258	$	41,594,775
Gross profit		40,201,265		13,423,067		7,183,786		19,594,413
Net income		8,165,791		4,830,477		1,941,417		1,393,897
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	4,405,327	$	2,396,596	$	1,076,230	$	932,501

Note 9 - Net Income Per Common Share (Tables)

9 Months Ended

May 31, 2013

Earnings Per Share [Text Block]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended				Nine Months Ended
Numerators:	May 31, 2013		May 31, 2012		May 31, 2013		May 31, 2012
Net income attributable to NTIC	$	927,112	$	1,454,037	$	1,751,144	$	3,018,987

Denominator:
Basic – weighted shares outstanding		4,421,379		4,399,290		4,415,452		4,379,175
Weighted shares assumed upon exercise of stock options		47,482		61,754		49,322		65,297
Diluted – weighted shares outstanding		4,468,861		4,461,044		4,464,774		4,448,472
Basic earnings per share:	$	0.21	$	0.33	$	0.40	$	0.69
Diluted earnings per share:	$	0.21	$	0.33	$	0.39	$	0.68

Note 11 - Geographic And Segment Information (Tables)

3 Months Ended

9 Months Ended

May 31, 2013

Note 11 - Geographic And Segment Information (Tables) [Line Items]

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	Three Months Ended						Nine Months Ended
	May 31, 2013			May 31, 2012			May 31, 2013			May 31, 2012
Inside the U.S.A. to unaffiliated customers		69.8	%		58.0	%		68.9	%		61.2	%
Outside the U.S.A to:
Joint ventures in which the Company is a shareholder directly and indirectly		11.1	%		10.9	%		14.9	%		12.6	%
Unaffiliated customers		19.1	%		31.1	%		16.2	%		26.2	%
		100.0	%		100.0	%		100.0	%		100.0	%

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]

	Nine Months Ended
	May 31, 2013		% of Total Fees for Services Provided to Joint Ventures			May 31, 2012			% of Total Fees for Services Provided to Joint Ventures
China*	$	1,468,622		26.5	%	$	—			0.0	%
Germany		742,213		13.4	%		742,171			21.3	%
Japan		548,618		9.9	%		763,548			22.0	%
Thailand*		471,074		8.5	%		—			0.0	%
Korea**		409,997		7.4	%		138,149			4.0	%
France		381,043		6.9	%		397,123			11.4	%
Poland		379,650		6.9	%		341,603			9.8	%
Sweden		305,619		5.5	%		446,191			12.8	%
Finland		245,426		4.4	%		378,751			10.9	%
United Kingdom		168,005		3.1	%		244,017			7.0	%
India		—		0.0	%		(192,758	)		(5.5	)%
Other		414,838		7.5	%		218,920			6.3	%
	$	5,535,105		100.0	%	$	3,477,715			100.0	%

	Three Months Ended				Nine Months Ended
	May 31, 2013		May 31, 2012		May 31, 2013		May 31, 2012
ZERUST® sales	$	5,418,271	$	7,220,258	$	14,923,966	$	16,243,683
Natur-Tec™ sales		458,762		584,646		1,491,164		1,367,663
	$	5,877,033	$	7,804,904	$	16,415,130	$	17,611,346

Reconciliation of Cost of Good Sold from Segments to Consolidated [Table Text Block]

	Three Months Ended										Nine Months Ended
	May 31, 2013		% of Product Sales*			May 31, 2012		% of Product Sales*			May 31, 2013		% of Product Sales*			May 31, 2012		% of Product Sales*
Direct cost of goods sold
ZERUST®	$	3,115,980		57.5	%	$	3,046,644		42.2	%	$	8,383,345		56.2	%	$	8,074,031		49.7	%
Natur-Tec®		367,485		80.1	%		501,749		85.8	%		1,260,305		84.5	%		1,160,014		84.8	%
Indirect cost of goods sold		570,899		—			595,121		—			1,735,599		—			1,599,027		—
Total net cost of goods sold	$	4,054,364				$	4,143,514				$	11,379,249				$	10,833,072

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	At May 31, 2013
	Brazil		North America		Total
Total assets	$	1,308,385	$	45,202,928	$	46,511,313

	At August 31, 2012
	Brazil		North America		Total
Total assets	$	1,744,693	$	40,132,934	$	41,877,627

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Nine Months Ended May 31, 2013
	Brazil			North America		Total
Net sales	$	1,699,084		$	14,716,046	$	16,415,130
Operating income	$	(263,353	)	$	3,600,643	$	3,337,290

	Nine Months Ended May 31, 2012
	Brazil		North America		Total
Net sales	$	4,004,399	$	13,606,947	$	17,611,346
Operating income	$	1,780,269	$	2,382,388	$	4,162,657

Fees For Services Provided to Joint Ventures [Member]

Note 11 - Geographic And Segment Information (Tables) [Line Items]

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]

	Three Months Ended
	May 31, 2013		% of Total Fees for Services Provided to Joint Ventures			May 31, 2012			% of Total Fees for Services Provided to Joint Ventures
China*	$	524,724		27.3	%	$	—			0.0	%
Germany		250,000		13.0	%		241,338			32.9	%
Japan		177,432		9.3	%		260,026			35.4	%
Thailand*		169,085		8.8	%		—			0.0	%
Korea**		147,867		7.7	%		61,152			8.4	%
Sweden		141,000		7.4	%		141,257			19.2	%
Poland		113,339		5.9	%		113,305			15.4	%
France		104,645		5.5	%		128,480			17.5	%
Finland		85,246		4.4	%		127,344			17.3	%
United Kingdom		65,193		3.4	%		83,879			11.4	%
India		—		0.0	%		(492,602	)		(67.1	)%
Other		139,416		7.3	%		70,158			9.6	%
	$	1,917,947		100.0	%	$	734,337			100.0	%

Note 2 - NTI ASEAN (Details)			1 Months Ended
Note 2 - NTI ASEAN (Details)	Sep. 30, 2012 NTI ASEAN [Member]	Aug. 31, 2012 NTI ASEAN [Member]	Sep. 30, 2012 Capitalization Rate To Determine Fair Value of NTI Asean [Member]
Note 2 - NTI ASEAN (Details) [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Business Acquisition, Percentage of Voting Interests Acquired	10.00%
Business Acquisition, Ownership Percentage Subsequent to Acquisition	60.00%
Fair Value Inputs, Discount Rate			25.00%

Note 2 - NTI ASEAN (Details) - Allocation of the total transaction amount: (USD $)	9 Months Ended
	May 31, 2013
Net assets acquired (liabilities assumed):
Cash and cash equivalents	$ 1,613,000
Accounts receivables	1,342,000
Investments in joint ventures	4,967,000
Value of assets	7,922,000
Purchase price:
Fair value of non-controlling interest	3,961,000
Value of previously held interest	3,961,000
Total consideration	$ 7,922,000

Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: [Line Items]
Net sales	$ 5,877,033	$ 7,804,904	$ 16,415,130	$ 17,611,346
Cost of goods sold	4,054,364	4,143,514	11,379,249	10,833,072
Gross profit	1,822,669	3,661,390	4,935,881	6,778,274
Joint venture operations	3,358,282	2,557,309	9,268,174	7,883,042
Operating expenses	3,687,180	3,780,363	10,966,765	10,498,659
Operating income	1,493,771	2,438,336	3,337,290	4,162,657
Income before income tax expense	1,445,769	2,454,623	3,323,460	4,200,035
Income tax expense	158,000	814,000	532,000	1,020,000
Net income	1,287,769	1,640,623	2,791,460	3,180,035
Net income attributable to non-controlling interest	360,657	186,586	1,040,316	161,048
Net income attributable to NTIC	927,112	1,454,037	1,751,144	3,018,987
Net income per common diluted share (in Dollars per share)	$ 0.21	$ 0.33	$ 0.39	$ 0.68
As Reported [Member]
Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: [Line Items]
Net sales		7,804,904		17,611,346
Cost of goods sold		4,143,514		10,833,072
Gross profit		3,661,390		6,778,274
Joint venture operations		2,557,309		7,883,042
Operating expenses		3,780,363		10,498,659
Operating income		2,438,336		4,162,657
Income before income tax expense		2,454,623		4,200,035
Income tax expense		814,000		1,020,000
Net income		1,640,623		3,180,035
Net income attributable to non-controlling interest		186,586		161,048
Net income attributable to NTIC		1,454,037		3,018,987
Net income per common diluted share (in Dollars per share)		$ 0.33		$ 0.68
NTI ASEAN [Member]
Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: [Line Items]
Joint venture operations		870,663		2,569,943
Operating expenses		110,637		133,772
Operating income		760,026		2,436,171
Income before income tax expense		760,026		2,436,171
Income tax expense		99,208		284,019
Net income		660,818		2,152,152
Net income attributable to non-controlling interest		(264,327)		(860,861)
Net income attributable to NTIC		396,491		1,291,291
Net income per common diluted share (in Dollars per share)		$ 0.09		$ 0.29
Eliminated in Consolidation [Member]
Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: [Line Items]
Joint venture operations		(384,115)		(1,076,230)
Operating income		(384,115)		(1,076,230)
Income before income tax expense		(384,115)		(1,076,230)
Net income		(384,115)		(1,076,230)
Net income attributable to NTIC		(384,115)		(1,076,230)
Net income per common diluted share (in Dollars per share)		$ (0.09)		$ (0.24)
Pro Forma [Member]
Note 2 - NTI ASEAN (Details) - Pro Forma Effects of Consolidation of NTI Asean on the Company's Consolidated Financial Statements as of the Beginning of the Period For the Three Months Ended November 30, 2011: [Line Items]
Net sales		7,804,904		17,611,346
Cost of goods sold		4,143,514		10,833,072
Gross profit		3,661,390		6,778,274
Joint venture operations		3,043,857		9,376,755
Operating expenses		3,891,000		10,632,431
Operating income		2,814,247		5,522,598
Income before income tax expense		2,830,534		5,559,976
Income tax expense		913,208		1,304,019
Net income		1,917,326		4,255,957
Net income attributable to non-controlling interest		(77,741)		(699,813)
Net income attributable to NTIC		$ 1,466,413		$ 3,234,048
Net income per common diluted share (in Dollars per share)		$ 0.33		$ 0.73

Note 3 - Inventories (Details) - Inventories (USD $)	May 31, 2013	Aug. 31, 2012
Inventories [Abstract]
Production materials	$ 1,140,800	$ 1,462,615
Finished goods	4,076,176	2,688,582
	$ 5,216,976	$ 4,151,197

Note 4 - Property and Equipment, Net (Details) - Components of Property and Equipment, Net (USD $)	May 31, 2013	Aug. 31, 2012
Components of Property and Equipment, Net [Abstract]
Land	$ 310,365	$ 310,365
Buildings and improvements	4,302,151	3,406,674
Machinery and equipment	3,173,684	2,908,021
	7,786,200	6,625,060
Less accumulated depreciation	(2,660,067)	(2,336,442)
	$ 5,126,133	$ 4,288,618

Note 5 - Patents and Trademarks, Net (Details) (USD $)	9 Months Ended
Note 5 - Patents and Trademarks, Net (Details) (USD $)	May 31, 2013
Note 5 - Patents and Trademarks, Net (Details) [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months (in Dollars)	$ 80,000
Patents and Trademarks [Member]
Note 5 - Patents and Trademarks, Net (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years

Note 5 - Patents and Trademarks, Net (Details) - Patents and Trademarks, Net (USD $)	May 31, 2013	Aug. 31, 2012
Patents and Trademarks, Net [Abstract]
Patents and trademarks	$ 2,097,872	$ 1,945,785
Less accumulated amortization	(1,036,147)	(984,604)
	$ 1,061,725	$ 961,181

Note 6 - Investments in Joint Ventures (Details) (NTI ASEAN [Member])	Sep. 30, 2012	Aug. 31, 2012
NTI ASEAN [Member]
Note 6 - Investments in Joint Ventures (Details) [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Business Acquisition, Percentage of Voting Interests Acquired	10.00%

Note 6 - Investments in Joint Ventures (Details) - Condensed Balance Sheet of EXCOR and NTI ASEAN, and All Other Joint Ventures (USD $)	May 31, 2013	Aug. 31, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Current assets	$ 63,547,204	$ 61,973,725
Total assets	69,688,319	68,585,974
Current liabilities	19,288,471	18,686,181
Noncurrent liabilities	3,358,593	4,700,458
Joint ventures’ equity	47,041,255	45,199,335
Northern Technologies International Corporation’s share of joint ventures’ equity	23,320,080	21,461,492
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	20,877,265	19,403,150
EXCOR [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Current assets	23,056,084	24,357,139
Total assets	25,425,172	26,620,589
Current liabilities	3,056,560	4,749,574
Joint ventures’ equity	22,368,612	21,871,015
Northern Technologies International Corporation’s share of joint ventures’ equity	11,184,308	10,935,509
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	11,153,403	10,904,604
China [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Current assets	13,964,465
Total assets	13,993,902
Current liabilities	6,212,433
Noncurrent liabilities	869,532
Joint ventures’ equity	6,911,937
Northern Technologies International Corporation’s share of joint ventures’ equity	3,455,969
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	3,405,969
All Other [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Current assets	26,526,655	22,257,619
Total assets	30,269,245	26,442,929
Current liabilities	10,019,478	8,172,750
Noncurrent liabilities	2,489,061	3,644,493
Joint ventures’ equity	17,760,706	14,625,686
Northern Technologies International Corporation’s share of joint ventures’ equity	8,679,803	6,840,579
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	6,327,893	5,184,101
NTI ASEAN [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Current assets		15,358,967
Total assets		15,522,456
Current liabilities		5,763,857
Noncurrent liabilities		1,055,965
Joint ventures’ equity		8,702,634
Northern Technologies International Corporation’s share of joint ventures’ equity		3,685,404
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings		$ 3,314,445

Note 6 - Investments in Joint Ventures (Details) - Condensed Income Statement of EXCOR and NTI ASEAN, and All Other Joint Ventures: (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Condensed Income Statements, Captions [Line Items]
Net sales			$ 82,788,711	$ 83,746,872
Gross profit			39,447,084	40,201,265
Net income			7,626,711	8,165,791
Northern Technologies International Corporation’s share of equity in income of joint ventures	1,440,335	1,822,972	3,733,069	4,405,327
EXCOR [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			26,043,775	25,785,840
Gross profit			13,624,792	13,423,067
Net income			4,954,595	4,830,477
Northern Technologies International Corporation’s share of equity in income of joint ventures			2,478,109	2,396,596
China [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			10,802,206
Gross profit			5,134,820
Net income			815,664
Northern Technologies International Corporation’s share of equity in income of joint ventures			407,809
All Other [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			45,942,730	41,594,775
Gross profit			20,687,472	19,594,413
Net income			1,856,452	1,393,897
Northern Technologies International Corporation’s share of equity in income of joint ventures			847,151	932,501
NTI ASEAN [Member]
Condensed Income Statements, Captions [Line Items]
Net sales				16,366,258
Gross profit				7,183,786
Net income				1,941,417
Northern Technologies International Corporation’s share of equity in income of joint ventures				$ 1,076,230

Note 7 - Corporate Debt (Details) (USD $)	9 Months Ended
Note 7 - Corporate Debt (Details) (USD $)	May 31, 2013	May 31, 2012
Note 7 - Corporate Debt (Details) [Line Items]
Long-term Debt, Gross (in Dollars)	$ 952,444
Monthly Payments [Member] \| Term Loan [Member]
Note 7 - Corporate Debt (Details) [Line Items]
Debt Instrument, Periodic Payment, Principal (in Dollars)	6,343
Term Loan [Member]
Note 7 - Corporate Debt (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.15%
Term Loan and Line of Credit Agreements "Loan Agreements" [Member]
Note 7 - Corporate Debt (Details) [Line Items]
Debt Instrument, Covenants, Fixed Charge Coverage Ratio	1.10:1.00
Revolving Credit Facility [Member]
Note 7 - Corporate Debt (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.15%
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)	$ 3,000,000
Line of Credit Facility, Interest Rate at Period End	2.85%	3.20%
Debt, Weighted Average Interest Rate	3.02%	3.16%

Note 8 - Stockholders' Equity (Details) (USD $)	9 Months Ended
Note 8 - Stockholders' Equity (Details) (USD $)	May 31, 2013	May 31, 2012
Note 8 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	118,294	26,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in Dollars per share)	$ 10.25	$ 16.45
Common Stock Bonuses [Member]
Note 8 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		42,707
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)		$ 14.42
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Aggregate Fair Value (in Dollars)		$ 615,830

Note 8 - Stockholders' Equity (Details) - Exercised Stock Options (USD $)	9 Months Ended
	May 31, 2012	May 31, 2013 Exercise 1 [Member]	May 31, 2013 Exercise 2 [Member]	May 31, 2013 Exercise 3 [Member]	May 31, 2013 Exercise 4 [Member]	May 31, 2013 Exercise 5 [Member]
Note 8 - Stockholders' Equity (Details) - Exercised Stock Options [Line Items]
Options Exercised	1,966	25,140	4,000	1,734	1,500	666
Exercise Price (in Dollars per share)	$ 7.65	$ 9.95	$ 8.57	$ 7.65	$ 9.76	$ 7.75

Note 9 - Net Income Per Common Share (Details) - Reconciliation of the Earnings Per Share Computations (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Reconciliation of the Earnings Per Share Computations [Abstract]
Net income attributable to NTIC (in Dollars)	$ 927,112	$ 1,454,037	$ 1,751,144	$ 3,018,987
Basic – weighted shares outstanding	4,421,379	4,399,290	4,415,452	4,379,175
Weighted shares assumed upon exercise of stock options	47,482	61,754	49,322	65,297
Diluted – weighted shares outstanding	4,468,861	4,461,044	4,464,774	4,448,472
Basic earnings per share: (in Dollars per share)	$ 0.21	$ 0.33	$ 0.40	$ 0.69
Diluted earnings per share: (in Dollars per share)	$ 0.21	$ 0.33	$ 0.39	$ 0.68

Note 10 - Stock-Based Compensation (Details) (USD $)	9 Months Ended
Note 10 - Stock-Based Compensation (Details) (USD $)	May 31, 2013	May 31, 2012
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term		5 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	118,294	26,000
Allocated Share-based Compensation Expense, Net of Tax, Per Share (in Dollars per share)	$ 0.05
Allocated Share-based Compensation Expense, Estimate, Remainder of Fiscal Year	$ 93,077
Allocated Share-based Compensation Expense, Estimate, Next Fiscal Year	185,815
Allocated Share-based Compensation Expense, Estimate, Fiscal Year Two	99,964
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)	$ 5.53	$ 7.14
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years 175 days	1 year 299 days
Net of Estimated Forfeitures [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	398,849
Employee Stock Option [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Allocated Share-based Compensation Expense	$ 213,374	$ 216,712
2007 Plan [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	800,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years
2007 Plan [Member] \| Minimum [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
2007 Plan [Member] \| Maximum [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
ESPP [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	100,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	90.00%
Minimum [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years
Maximum [Member]
Note 10 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	10 years

Note 10 - Stock-Based Compensation (Details) - Black-Scholes Option-Pricing Model Assumptions	9 Months Ended
	May 31, 2012	May 31, 2013 Minimum [Member]	May 31, 2013 Maximum [Member]
Note 10 - Stock-Based Compensation (Details) - Black-Scholes Option-Pricing Model Assumptions [Line Items]
Dividend yield	0.00%		0.00%
Expected volatility	48.80%		48.00%
Expected life of option (years)	5 years	5 years	10 years
Average risk-free interest rate	1.31%		0.71%

Note 11 - Geographic And Segment Information (Details) - Net Sales By Geographic Location as Percentage of Total Consolidated Net Sales (Percentage of Total Consolidated Net Sales [Member])	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Note 11 - Geographic And Segment Information (Details) - Net Sales By Geographic Location as Percentage of Total Consolidated Net Sales [Line Items]
Net Sales, Percentage	100.00%	100.00%	100.00%	100.00%
Inside the U.S.A to Unaffiliated Customers [Member]
Note 11 - Geographic And Segment Information (Details) - Net Sales By Geographic Location as Percentage of Total Consolidated Net Sales [Line Items]
Net Sales, Percentage	69.80%	58.00%	68.90%	61.20%
Joint Ventures In Which The Company Is A Shareholder Directly And Indirectly - Outside the U.S.A [Member]
Note 11 - Geographic And Segment Information (Details) - Net Sales By Geographic Location as Percentage of Total Consolidated Net Sales [Line Items]
Net Sales, Percentage	11.10%	10.90%	14.90%	12.60%
Unaffiliated Customers - Outside the U.S.A [Member]
Note 11 - Geographic And Segment Information (Details) - Net Sales By Geographic Location as Percentage of Total Consolidated Net Sales [Line Items]
Net Sales, Percentage	19.10%	31.10%	16.20%	26.20%

Note 11 - Geographic And Segment Information (Details) - Fees For Services Provided to Joint Ventures By Geographic Location as a Percentage of Total Fees for Services Provided to Joint Ventures (USD $)

3 Months Ended

9 Months Ended

May 31, 2013

May 31, 2012

May 31, 2013

May 31, 2012

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

$ 1,917,947

$ 734,337

$ 5,535,105

$ 3,477,715

Percentage of Total Fees for Services Provided to Joint Ventures

100.00%

China [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

524,724

^[1]

1,468,622

^[1]

Percentage of Total Fees for Services Provided to Joint Ventures

27.30%

^[1]

0.00%

^[1]

26.50%

^[1]

0.00%

^[1]

Germany [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

250,000

241,338

742,213

742,171

Percentage of Total Fees for Services Provided to Joint Ventures

13.00%

32.90%

13.40%

21.30%

Japan [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

177,432

260,026

548,618

763,548

Percentage of Total Fees for Services Provided to Joint Ventures

9.30%

35.40%

9.90%

22.00%

Thailand [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

169,085

^[1]

471,074

^[1]

Percentage of Total Fees for Services Provided to Joint Ventures

8.80%

^[1]

0.00%

^[1]

8.50%

^[1]

0.00%

^[1]

Korea [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

147,867

^[1],[2]

61,152

^[1],[2]

409,997

^[2]

138,149

^[2]

Percentage of Total Fees for Services Provided to Joint Ventures

7.70%

^[1],[2]

8.40%

^[1],[2]

7.40%

^[2]

4.00%

^[2]

Sweden [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

141,000

141,257

305,619

446,191

Percentage of Total Fees for Services Provided to Joint Ventures

7.40%

19.20%

5.50%

12.80%

Poland [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

113,339

113,305

379,650

341,603

Percentage of Total Fees for Services Provided to Joint Ventures

5.90%

15.40%

6.90%

9.80%

France [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

104,645

128,480

381,043

397,123

Percentage of Total Fees for Services Provided to Joint Ventures

5.50%

17.50%

6.90%

11.40%

Finland [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

85,246

127,344

245,426

378,751

Percentage of Total Fees for Services Provided to Joint Ventures

4.40%

17.30%

4.40%

10.90%

United Kingdom [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

65,193

83,879

168,005

244,017

Percentage of Total Fees for Services Provided to Joint Ventures

3.40%

11.40%

3.10%

7.00%

India [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

(492,602)

(192,758)

Percentage of Total Fees for Services Provided to Joint Ventures

0.00%

(67.10%)

0.00%

(5.50%)

Other Countries [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

$ 139,416

$ 70,158

$ 414,838

$ 218,920

Percentage of Total Fees for Services Provided to Joint Ventures

7.30%

9.60%

7.50%

6.30%

[1]	Joint venture owned by NTI Asean.
[2]	Joint venture owned by NTI Asean as of May 31, 2013, but not as of May 31, 2012. NTI Asean results are not included on the consolidated financial statements for the three months ended May 31, 2012. (See Note 2)

3 Months Ended

9 Months Ended

May 31, 2013

May 31, 2012

May 31, 2013

May 31, 2012

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

$ 1,917,947

$ 734,337

$ 5,535,105

$ 3,477,715

Percentage of Total Fees for Services Provided to Joint Ventures

100.00%

China [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

524,724

^[1]

1,468,622

^[1]

Percentage of Total Fees for Services Provided to Joint Ventures

27.30%

^[1]

0.00%

^[1]

26.50%

^[1]

0.00%

^[1]

Germany [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

250,000

241,338

742,213

742,171

Percentage of Total Fees for Services Provided to Joint Ventures

13.00%

32.90%

13.40%

21.30%

Japan [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

177,432

260,026

548,618

763,548

Percentage of Total Fees for Services Provided to Joint Ventures

9.30%

35.40%

9.90%

22.00%

Thailand [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

169,085

^[1]

471,074

^[1]

Percentage of Total Fees for Services Provided to Joint Ventures

8.80%

^[1]

0.00%

^[1]

8.50%

^[1]

0.00%

^[1]

Korea [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

147,867

^[1],[2]

61,152

^[1],[2]

409,997

^[2]

138,149

^[2]

Percentage of Total Fees for Services Provided to Joint Ventures

7.70%

^[1],[2]

8.40%

^[1],[2]

7.40%

^[2]

4.00%

^[2]

France [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

104,645

128,480

381,043

397,123

Percentage of Total Fees for Services Provided to Joint Ventures

5.50%

17.50%

6.90%

11.40%

Poland [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

113,339

113,305

379,650

341,603

Percentage of Total Fees for Services Provided to Joint Ventures

5.90%

15.40%

6.90%

9.80%

Sweden [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

141,000

141,257

305,619

446,191

Percentage of Total Fees for Services Provided to Joint Ventures

7.40%

19.20%

5.50%

12.80%

Finland [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

85,246

127,344

245,426

378,751

Percentage of Total Fees for Services Provided to Joint Ventures

4.40%

17.30%

4.40%

10.90%

United Kingdom [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

65,193

83,879

168,005

244,017

Percentage of Total Fees for Services Provided to Joint Ventures

3.40%

11.40%

3.10%

7.00%

India [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

(492,602)

(192,758)

Percentage of Total Fees for Services Provided to Joint Ventures

0.00%

(67.10%)

0.00%

(5.50%)

Other Countries [Member]

Segment Reporting, Revenue Reconciling Item [Line Items]

Fees for Services Provided to Joint Ventures (in Dollars)

$ 139,416

$ 70,158

$ 414,838

$ 218,920

Percentage of Total Fees for Services Provided to Joint Ventures

7.30%

9.60%

7.50%

6.30%

[1]	Joint venture owned by NTI Asean.
[2]	Joint venture owned by NTI Asean as of May 31, 2013, but not as of May 31, 2012. NTI Asean results are not included on the consolidated financial statements for the three months ended May 31, 2012. (See Note 2)

Note 11 - Geographic And Segment Information (Details) - Net Sales By Segment (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Sales	$ 5,877,033	$ 7,804,904	$ 16,415,130	$ 17,611,346
ZERUST [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Sales	5,418,271	7,220,258	14,923,966	16,243,683
Natur-Tec [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net Sales	$ 458,762	$ 584,646	$ 1,491,164	$ 1,367,663

Note 11 - Geographic And Segment Information (Details) - Cost of Goods Sold By Segment (USD $)

3 Months Ended

9 Months Ended

May 31, 2013

May 31, 2012

May 31, 2013

May 31, 2012

Direct cost of goods sold

Cost of Goods Sold

$ 4,054,364

$ 4,143,514

$ 11,379,249

$ 10,833,072

ZERUST [Member] | Direct Cost of Goods Sold [Member]

Direct cost of goods sold

Cost of Goods Sold

3,115,980

3,046,644

8,383,345

8,074,031

% of Product Sales

57.50%

^[1]

42.20%

^[1]

56.20%

^[1]

49.70%

^[1]

Natur-Tec [Member] | Direct Cost of Goods Sold [Member]

Direct cost of goods sold

Cost of Goods Sold

367,485

501,749

1,260,305

1,160,014

% of Product Sales

80.10%

^[1]

85.80%

^[1]

84.50%

^[1]

84.80%

^[1]

Indirect Cost of Goods Sold [Member]

Direct cost of goods sold

Cost of Goods Sold

$ 570,899

$ 595,121

$ 1,735,599

$ 1,599,027

% of Product Sales

^[1]

[1]	The percent of segment sales is calculated by dividing the direct cost of goods sold for each individual segment category by the net sales for each segment category.

Note 11 - Geographic And Segment Information (Details) - Operating income by geographic distribution (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Segment Reporting Information [Line Items]
Net sales	$ 5,877,033	$ 7,804,904	$ 16,415,130	$ 17,611,346
Operating income	1,493,771	2,438,336	3,337,290	4,162,657
Brazil [Member]
Segment Reporting Information [Line Items]
Net sales			1,699,084	4,004,399
Operating income			(263,353)	1,780,269
North America [Member]
Segment Reporting Information [Line Items]
Net sales			14,716,046	13,606,947
Operating income			$ 3,600,643	$ 2,382,388

Note 12 - Research and Development (Details) (USD $)	3 Months Ended		9 Months Ended
Note 12 - Research and Development (Details) (USD $)	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012	May 31, 2013 Research and Development Contracts [Member]	Aug. 31, 2012 Research and Development Contracts [Member]
Note 12 - Research and Development (Details) [Line Items]
Research and Development Expense	$ 1,002,651	$ 1,067,454	$ 2,853,250	$ 2,856,536
Research and Development Arrangement, Contract to Perform for Others, Costs Incurred, Gross			206,046	297,258
Contract Receivable					143,395
Deferred Revenue						$ 96,861

Note 13 - Commitments and Contingencies (Details) (USD $)				9 Months Ended
	May 31, 2013	Aug. 31, 2012	May 31, 2012	May 31, 2013 Fiscal 2013 Bonus Plan [Member] Executive Officer [Member]	May 31, 2013 Fiscal 2013 Bonus Plan [Member]
Note 13 - Commitments and Contingencies (Details) [Line Items]
Percentage of Company's Earnings Before Interest, Taxes, and Other Income Available Under the Bonus Plan, Maximum					25.00%
Adjusted EBITOI As Percentage of Target EBITOI, Threshold To Pay Bonus					70.00%
Percentage of Individual Bonus Payout Determined By Actual Versus Targeted EBITOI Results				50.00%
Percentage of Individual's Payout Determined Upon Achievement of Certain Pre-Established Individual Performance Objectives				50.00%
Accrued Bonuses (in Dollars)	$ 580,000		$ 1,058,045
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year (in Dollars)	59,625
Operating Leases, Future Minimum Payments, Due in Two Years (in Dollars)	59,500
Operating Leases, Future Minimum Payments, Due Thereafter (in Dollars)	$ 0
Entity-Wide Trade Joint Venture Receivables, Three Joint Ventures, Percentage	67.10%	55.30%

Note 11 - Geographic And Segment Information (Details) - Total assets by geographic distribution (USD $)	May 31, 2013	Aug. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	$ 46,511,313	$ 41,877,627
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	1,308,385	1,744,693
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total assets	$ 45,202,928	$ 40,132,934