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

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES

Nature of Business

– Northern Technologies International Corporation and Subsidiaries (the Company) develop and market proprietary environmentally beneficial products and services in over

countries either directly or via a network of joint ventures, independent distributors and agents. The Company’s primary business is corrosion prevention marketed mainly under the ZERUST

brand. The Company has been selling its proprietary ZERUST

rust and corrosion inhibiting products and services to the automotive, electronics, electrical, mechanical, military and retail consumer markets for over

years, and more recently, has targeted and expanded into the oil and gas industry. The Company also sells a portfolio of biobased and certified compostable (fully biodegradable) polymer resin compounds and finished products under the Natur-Tec

brand. These products are intended to reduce the Company’s customers’ carbon footprint and provide environmentally sound disposal options. The Company’s

two

operating segments are ZERUST and Natur-Tec.

The Company participates, either directly or indirectly, in

active joint venture arrangements in North America, Europe and Asia. Each of these joint ventures generally manufactures and markets products in the geographic territory to which it is assigned. While most of the Company’s joint ventures exclusively sell rust and corrosion inhibiting products, some of the joint ventures also sell the Company’s Natur-Tec

resin compounds and finished products. The profits of joint ventures are shared by the respective joint venture owners in accordance with their respective ownership percentages. The Company typically owns

50%

or less of its joint venture entities and does

not

control the decisions of these entities, including dividend declaration or amount in any given year.

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

Principles of Consolidation

- NTIC evaluates its voting and variable interests in entities on a qualitative and quantitative basis. NTIC consolidates entities in which it concludes it has the power to direct the activities that most significantly impact an entity’s economic success and has the obligation to absorb losses or the right to receive benefits that could be significant to the entity. The consolidated financial statements include the accounts of Northern Technologies International Corporation, its wholly-owned subsidiaries, Northern Technologies Holding Company, LLC, NTIC (Shanghai) Co., Ltd. (NTIC China), ZERUST-EXCOR MEXICO, S. de R.L. de C.V (Zerust Mexico), NTIC Europe GmbH (NTI Europe), and, NTIC’s majority-owned subsidiary in India, Natur-Tec India Private Limited (Natur-Tec India), NTIC’s majority-owned subsidiary in Brazil, Zerust Prevenção de Corrosão S.A. (Zerust Brazil) and NTIC’s majority-owned holding company, NTI Asean LLC (NTI Asean). NTIC’s consolidated financial statements do

not

include the accounts of any of its joint ventures.

Non-Controlling Interests

– The Company owns

90%

of Natur-Tec India,

85%

of Zerust Brazil and

60%

of NTI Asean. The remaining ownership is accounted for as non-controlling interests and reported as part of equity in the consolidated financial statements. The Company allocates gains and losses to the non-controlling interest even when such allocation might result in a deficit balance, reducing the losses attributed to the controlling interest, changes in ownership interests are treated as equity transactions if the Company maintains control.

Net Sales

–The Company includes net sales to its joint ventures and net sales to unaffiliated customers as separate line items on its consolidated statements of operations. There are

sales originating from the Company’s joint ventures included in the amount, as the Company’s investments in its joint ventures are accounted for using the equity method.

Revenue Recognition

– The Company recognizes revenue from the sale of its products when persuasive evidence of an arrangement exists, the product has been delivered, the price is fixed and determinable and collection of the resulting receivable is reasonably assured. These criteria are met when risk of loss and title pass to the customer, distributor or joint venture entity. Sales and use taxes charged to customers are reported on a net basis.

Trade Receivable

– Payment terms for the Company’s unaffiliated customers are determined based on credit risk and vary by customer. The Company typically offers standard payment terms to unaffiliated customers of net

days. The Company does

not

accrue interest on past due accounts receivable. The Company reviews the credit histories of its customers before extending unsecured credit. The Company presents accounts and notes receivable, net of an allowance for doubtful accounts. Each quarter, the Company prepares an analysis of its ability to collect outstanding receivables that provides a basis for an allowance estimate for doubtful accounts. In doing so, the Company evaluates the age of its receivables, past collection history, current financial conditions of key customers and its joint ventures, and economic conditions. Based on this evaluation, the Company establishes a reserve for specific accounts and notes receivable that it believes are uncollectible, as well as an estimate of uncollectible receivables

not

specifically known. The Company believes that an analysis of historical trends and its current knowledge of potential collection problems provide the Company with sufficient information to establish a reasonable estimate for an allowance for doubtful accounts. In the event the Company determines that a smaller or larger uncollectible accounts reserve is appropriate; the Company records a credit or charge to selling expense in the period that it made such determination. Accounts receivable have been reduced by an allowance for uncollectible accounts of

$40,000

as of

August 31, 2017

and

2016.

Accounts are considered past due based on terms agreed upon between the Company and the customer. Accounts receivable are written-off only after all collection attempts have failed and are based on individual credit evaluation and specific circumstances of the customer.

Trade Receivables from Joint Ventures

– Trade receivables from joint ventures arise from sales of products the Company makes to its joint ventures. Payment terms for the Company’s joint ventures also are determined based on credit risk; however, additional consideration also is given to the individual joint venture due to the transportation time associated with ocean delivery of most products and certain other factors. Generally, accounts receivable from the Company’s joint ventures unpaid after

days are considered past due. The Company does

not

accrue interest on past due balances. The Company periodically reviews amounts due from its joint ventures for collectability, and based on past experience and continuous review of the balances due, determined an allowance for doubtful accounts related to its joint venture receivables is

not

necessary as of

August 31, 2017

2016.

Fees for Services Provided to Joint Ventures –

The Company provides services to its joint ventures including consulting, legal, travel, insurance, technical and marketing services. The Company receives fees for the services it provides to its joint ventures. The fees for services received by the Company from its joint ventures are generally based on either a flat fee or a percentage of net sales by the Company’s joint ventures depending on local laws and tax regulations. The Company recognizes revenues related to fees for services provided to its joint ventures when earned, amounts are determinable and collectability is reasonably assured. Under the Company’s agreements with its joint ventures, amounts are earned when product is shipped from joint venture facilities. The Company reviews the financial situation of each of its joint ventures to assist in the likelihood of collections on amounts earned. The Company accounts for these fees on a cash basis if uncertainty exists surrounding the collection of such fees.

Cash and Cash Equivalents

- The Company includes as cash and cash equivalents highly liquid, short-term investments with maturity of

three

months or less when purchased, which are readily convertible into known amounts of cash. The Company maintains its cash in high quality financial institutions. The balances, at times,

may

exceed federally insured limits.

Available for Sale Securities

– Available for sale securities are recorded at fair value. Unrealized holding gains and losses on available for sale securities are excluded from earnings.

Inventories

- Inventories are recorded at the lower of cost (

first

-in,

first

-out basis) or market.

Property and Depreciation

- Property and equipment are stated at cost. Depreciation is computed using the straight-line method based on the estimated service lives of the various assets as follows:

Buildings and improvements (years)		5	-	30
Machinery and equipment (years)		3	-	10

Patents and Trademarks

– Patents and Trademarks, including acquisition costs, are stated at cost, less accumulated amortization. Amortization is computed using the straight-line method over the estimated useful lives of the respective assets. Upon retirement, the cost of assets disposed and the related accumulated amortization are removed from the accounts and any resulting gain or loss is credited or charged to operations.

Investments in Joint Ventures

- Investments in the Company’s joint ventures are accounted for using the equity method. Under the equity method, investments are initially recorded at cost and are adjusted for dividends, distributed and undistributed earnings and losses, changes in foreign currency exchange rates and additional investments. In the event the Company’s share of joint venture’s cumulative losses exceeds the Company’s investment balance, the balance is reported at

zero

value until proportionate income exceeds the losses. The Company assesses its joint ventures for impairment on an annual basis as of

August 31

of each year as part of its fiscal year end analysis. In addition to the annual review for impairment, the Company reviews the operating results of each joint venture on a quarterly basis in comparison to its historical operating results and its accrual of fees for services provided to joint ventures. If the operating results of a joint venture do

not

meet financial performance expectations, an additional evaluation is performed on the joint venture. The Company’s evaluation of its investments in joint ventures requires the Company to make assumptions about future cash flows of its joint ventures. These assumptions require significant judgment and actual results

may

differ from assumed or estimated amounts. All investments in joint ventures have positive equity as of

August 31, 2017

and

2016.

The Company considers any of its joint ventures to be significant and discloses entity specific financial information if the joint venture’s income or assets make up more than

20%

of the Company’s total assets or income.

The Company classifies distributions received from its joint ventures based on the nature of the distributions, generally, as a return on its investment in operating activities on the consolidated statement of cash flows.

Investment at Carrying Value

– If the Company is

longer able to exercise significant influence over operating and financial policy of a joint venture previously accounted for under the equity method, it maintains the investment at the carrying value as of the date that significant influence

longer exists and discontinues accruing the proportionate earnings or losses of the investment.

Investments are considered to be impaired when a decline in fair value is judged to be other-than-temporary. Fair value is calculated based on publicly available market information or other estimates determined by management. The Company employs a systematic methodology on a quarterly basis that considers available quantitative and qualitative evidence in evaluating potential impairment of our investments. If the cost of an investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, credit quality, the duration and extent to which the fair value is less than cost, and for equity securities, the Company’s intent and ability to hold, or plans to sell, the investment. The Company also considers specific adverse conditions related to the financial health of and business outlook for the investee, including industry and sector performance, changes in technology, and operational and financing cash flow factors. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded to other income (expense) and a new cost basis in the investment is established.

Recoverability of Long-Lived Assets

- The Company reviews its long-lived assets whenever events or changes in circumstances indicate the carrying amount of the assets

may

not

be recoverable. The Company determines potential impairment by comparing the carrying value of the assets with expected net cash flows expected to be provided by operating activities of the business or related products. If the sum of the expected undiscounted future net cash flows is less than the carrying value, the Company evaluates if an impairment loss should be recognized. An impairment loss is measured by comparing the amount by which the carrying value exceeds the fair value of the asset.

Income Taxes

- The Company utilizes the asset and liability method of accounting for income taxes which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Deferred income tax assets and liabilities are determined based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date.

The Company records net deferred tax assets to the extent the Company believes these assets will more likely than

not

be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, the Company makes an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

The Company records uncertain tax positions on the basis of a

two

-step process whereby the Company determines whether it is more likely than

not

that the tax positions will be sustained based on the technical merits of the position and those tax positions that meet the more-likely-than-

not

recognition threshold. The Company recognizes the largest amount of tax benefit that is greater than

percent likely to be realized upon ultimate settlement with the related tax authority.

Foreign Currency Translation (Accumulated Other Comprehensive Income (Loss))

- The functional currency of NTIC China, Zerust Brazil, Natur-Tec India, Zerust Mexico, NTI Europe and each unconsolidated international joint venture is the applicable local currency. The translation of the applicable foreign currencies into U.S. dollars is performed for balance sheet accounts using exchange rates in effect at the balance sheet date and for revenue and expense accounts using an average monthly exchange rate. Translation gains or losses are reported as an element of other comprehensive income (loss).

The Company (excluding NTIC China, Zerust Brazil, Natur-Tec India, NTI Asean, Zerust Mexico, NTI Europe and its joint ventures) conducts all foreign transactions based on the U.S. dollar. Since investments in joint ventures are accounted for using the equity method, any changes in foreign currency exchange rates are reflected as a foreign currency translation adjustment and does

not

change the equity in income from joint ventures reflected in the Company’s consolidated statements of operations.

Fair Value of Financial Instruments

– The carrying value of cash and cash equivalents, available for sale securities, short-term accounts and notes receivable, notes payable, trade accounts payables, and other accrued expenses approximate fair value because of the short maturity of those instruments.

Shipping and Handling

- The Company records all amounts billed to customers in a sales transaction related to shipping and handling as sales. The Company records costs related to shipping and handling in cost of goods sold.

Research and Development

- The Company expenses all costs related to product research and development as incurred.

Common Stock

– The Company issues authorized but unissued shares of common stock upon the exercise of stock options.

Stock-Based Compensation

– The Company recognizes compensation cost relating to share-based payment transactions, including grants of employee stock options and transactions under the Company’s employee stock purchase plan, in its consolidated financial statements. That cost is measured based on the fair value of the equity or liability instruments issued. The Company measures the cost of employee services received in exchange for stock options and other stock-based awards based on the grant-date fair value of the award, and recognizes the cost over the period the employee is required to provide services for the award (generally the vesting term).

Use of Estimates

- The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Certain amounts reported in the consolidated financial statements for the previous reporting period have been reclassified to conform to the current period presentation. Expenses previously recorded as “Expenses incurred in support of joint ventures” have been reclassified as “General and administrative expenses” based on the reduction in direct costs associated with supporting the joint ventures.

Note 2 - Recently Issued Accounting Pronouncements	12 Months Ended
Note 2 - Recently Issued Accounting Pronouncements	Aug. 31, 2017
Notes to Financial Statements
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	2. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (FASB) issued Revenue from Contracts with Customers, Topic 606 (Accounting Standards Update (ASU) No. 2014 - 09 ), which provides a framework for the recognition of revenue, with the objective that recognized revenues properly reflect amounts an entity is entitled to receive in exchange for goods and services. This guidance, which includes additional disclosure requirements regarding revenue, cash flows and obligations related to contracts with customers, was originally to be effective for the Company beginning in fiscal year 2018. In July 2015, the FASB confirmed a one -year deferral of the effective date of the new revenue standard which also allows early adoption as of the original effective date. The updated guidance will be effective for the Company’s first quarter of 2019. The Company is currently evaluating the impact of adopting ASU 2014 - 09 on its consolidated financial statements, but currently believes that the timeline established for implementation is attainable. In July 2015, the FASB issued ASU No. 2015 - 11, “ Inventory ”, which modifies the subsequent measurement of inventories recorded under a first -in- first -out or average cost method. Under the new standard, such inventories are required to be measured at the lower of cost and net realizable value. The new standard is effective for the Company’s fiscal year 2018, with prospective application. The Company does not expect the adoption of the provisions of ASU 2015 - 11 to have a material impact on its consolidated financial statements. During February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016 - 02, “ Leases .” ASU No. 2016 - 02 was issued to increase transparency and comparability among organizations by recognizing all lease transactions (with terms in excess of 12 months) on the balance sheet as a lease liability and a right-of-use asset (as defined). ASU No. 2016 - 02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with earlier application permitted. Upon adoption, the lessee will apply the new standard retrospectively to all periods presented or retrospectively using a cumulative effect adjustment in the year of adoption. The Company is currently assessing the effect that ASU No. 2016 - 02 will have on its consolidated financial statements. In March 2016, the FASB issued ASU No. 2016 - 07, “ Investments – Equity Method and Joint Ventures (Topic 323 ): Simplifying the Transition to the Equity Method of Accounting .” Among other things, the amendments in ASU 2016 - 07 eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The amendments should be applied prospectively upon their effective date to increases in the level of ownership interest or degree of influence that result in the adoption of the equity method. Early adoption is permitted. The Company is currently assessing the impact that ASU 2016 - 07 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016 - 09, Stock Compensation , which is intended to simplify several aspects of the accounting for share-based payment award transactions. The guidance will be effective for the fiscal year beginning after December 15, 2016, including interim periods within that year. The Company is currently assessing the impact that ASU 2016 - 09 will have on its consolidated financial statements. In August 2016, the FASB issued ASU No. 2016 - 15, Statement of Cash Flows, Classification of Certain Cash Receipts and Cash Payments ASU 2016 - 15 eliminates the diversity in practice related to the classification of certain cash receipts and payments for debt prepayments or extinguishment costs, the maturing of a zero coupon bond, the settlement of contingent liabilities arising from a business combination, proceeds from insurance settlements, distributions from certain equity method investees and beneficial interests obtained in a financial asset securitization. ASU 2016 - 15 designates the appropriate cash flow classification, including requirements to allocate certain components of these cash receipts and payments among operating, investing and financing activities. The guidance is effective for fiscal years beginning December 15, 2017. Early adoption is permitted. The Company is currently evaluating the effects of adopting ASU 2016 - 15 on its consolidated financial statements, but the adoption is not expected to have a significant impact on its consolidated financial statements. Although there are several other new accounting pronouncements issued or proposed by the FASB, which the Company has adopted or will adopt, as applicable, the Company does not believe any of these accounting pronouncements has had or will have a material impact on the Company’s consolidated financial position or operating results.

Note 6 - Investments in Joint Ventures

12 Months Ended

Aug. 31, 2017

Equity Method Investments and Joint Ventures Disclosure [Text Block]

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 conform with accounting principles generally accepted in the United States of America in all material respects. All material profits recorded that remain on the balance sheet on sales from the Company to its joint ventures and from joint ventures to other joint ventures have been eliminated for financial reporting purposes.

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

	As of August 31, 2017
	Total		EXCOR		All Other
Current assets	$	51,518,210	$	22,142,514	$	29,375,696
Total assets		55,633,891		24,301,194		31,332,697
Current liabilities		15,118,074		4,469,567		10,648,507
Noncurrent liabilities		181,210		—		181,210
Joint ventures’ equity		40,334,607		19,831,627		20,502,980
Northern Technologies International Corporation’s share of joint ventures’ equity		20,035,074		9,915,816		10,119,258
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	17,960,860	$	9,884,911	$	8,075,949

	Fiscal Year Ended August 31, 2017
	Total		EXCOR		All Other
Net sales	$	101,261,132	$	39,849,757	$	61,411,375
Gross profit		44,861,300		21,133,632		23,727,668
Net income		11,839,933		8,369,728		3,470,205
Northern Technologies International Corporation’s share of equity in income of joint ventures		5,898,908		4,185,988		1,712,920
Northern Technologies International Corporation's dividends received from joint ventures	$	6,377,054	$	5,379,062	$	997,992

	As of August 31, 2016
	Total		EXCOR		All Other
Current assets	$	48,922,924	$	22,928,810	$	25,994,114
Total assets		52,407,026		24,733,340		27,673,686
Current liabilities		12,433,700		3,485,231		8,948,469
Noncurrent liabilities		100,783		—		100,783
Joint ventures’ equity		39,872,543		21,248,109		18,624,434
Northern Technologies International Corporation’s share of joint ventures’ equity		19,840,774		10,624,056		9,216,728
Northern Technologies International Corporation's share of joint ventures’ undistributed earnings	$	17,779,912	$	10,593,151	$	7,186,761

	Fiscal Year Ended August 31, 2016
	Total		EXCOR		All Other
Net sales	$	90,646,833	$	35,138,214	$	55,508,619
Gross profit		40,440,726		18,635,421		21,805,305
Net income		9,534,771		7,049,462		2,485,309
Northern Technologies International Corporation’s share of equity in income from joint ventures		4,743,831		3,534,113		1,209,718
Northern Technologies International Corporation’s dividends received from joint ventures	$	5,503,314	$	4,364,700	$	1,165,614

The Company did

not

make any joint venture investments during fiscal

2017

or fiscal

2016.

Note 7 - China Operations	12 Months Ended
Note 7 - China Operations	Aug. 31, 2017
Notes to Financial Statements
Fair Value Disclosures [Text Block]	7. CHINA OPERATIONS Effective December 31, 2014, the Company terminated its joint venture agreements with its previous joint venture in China, Tianjin Zerust, began the process of liquidating the joint venture entity, and commenced operations in China through a wholly-owned subsidiary, NTIC (Shanghai) Co. Ltd. on January 1, 2015. Effective December 31, 2014, the Company’s investment in Tianjin Zerust was reported at carrying value based on the Company’s decreased level of influence over the entity, and the Company reclassified previously unrecognized gains on foreign currency translation from accumulated other comprehensive income. Any declines in the fair value were reflected as adjustments to the carrying value. Since it began the process of liquidating the joint venture entity on December 31, 2014, the Company has not received any proceeds from the assets of Tianjin Zerust. In addition, the Company has not received financial information or cooperation from its joint venture partner in determining the investment value for the year ended August 31, 2017 or 2016. During the fourth quarter of fiscal 2016, the Company obtained additional information regarding the financial position of the investment through the legal proceedings that have been ongoing (See Note 16 ). These circumstances resulted in the Company concluding an indication of impairment exists and that the fair value of the investment was $0 as of August 31, 2016 based on accounting principles generally accepted in the United States of America. See Note 16 regarding ongoing litigation involving Tianjin Zerust.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Note 8 - Corporate Debt	12 Months Ended
Note 8 - Corporate Debt	Aug. 31, 2017
Notes to Financial Statements
Debt Disclosure [Text Block]	8. CORPORATE DEBT 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 both August 31, 2017 and 2016. 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. The line of credit matures on January 7, 2018. The line of credit is subject to 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 agreement, the Company is subject to a minimum fixed charge coverage ratio of 1.10:1.00. As of August 31, 2017, the Company was in compliance with all debt covenants. The revolving credit facility allows the Company to request that PNC Bank issue letters of credit up to $1,200,000. The Company did not have any letters of credit reserved against the available letters of credit balance as of August 31, 2017 and 2016 with PNC Bank. The availability of advances under the line of credit are reduced by the face amount of any letter of credit issued and outstanding (whether or not drawn) under the revolving credit facility. As of August 31, 2017, the Company had $89,543 of letters of credit with JP Morgan Chase Bank that are performance based and set to expire between 2020 and 2022.

Note 9 - Stockholders' Equity	12 Months Ended
Note 9 - Stockholders' Equity	Aug. 31, 2017
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	9. STOCKHOLDERS’ EQUITY On January 15, 2015, the Company’s Board of Directors authorized the repurchase of up to $3,000,000 in shares of common stock through open market purchases or unsolicited or solicited privately negotiated transactions. This program has no expiration date but may be terminated by the Company’s Board of Directors at any time. As of August 31, 2017, up to $2,640,548 in shares of common stock remained available for repurchase under the stock repurchase program. During fiscal 2017, the Company repurchased and retired 14,525 shares of its common stock at an average price of $13.51 per share. During fiscal 2017, stock options to purchase an aggregate of 12,000 shares of common stock at an exercise price of $10.25 per share were exercised. 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 56,677 shares of its common stock to various employees and directors during fiscal 2017. The weighted average per share exercise price of the stock options is $13.40, which was equal to the fair market value of the Company’s common stock on the date of grant. No stock options to purchase shares of common stock were exercised during fiscal 2016. The Company granted stock options under the 2007 Plan to purchase an aggregate of 53,447 shares of its common stock to various employees and directors during fiscal 2016. The weighted average per share exercise price of the stock options is $14.85, which was equal to the fair market value of the Company’s common stock on the date of grant.

Note 10 - Net Income (Loss) Per Common Share

12 Months Ended

Aug. 31, 2017

Earnings Per Share [Text Block]

10.

NET INCOME (LOSS) PER COMMON SHARE

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

The following is a reconciliation of the earnings per share computation:

Numerator:	August 31, 2017		August 31, 2016
Net income (loss) attributable to NTIC	$	3,422,126	$	(867,514	)

Denominator:
Basic-weighted shares outstanding		4,528,611		4,537,504
Weighted shares assumed upon exercise of stock options		48,748		—
Diluted – weighted shares outstanding		4,577,359		4,537,504

Basic income (loss) earnings per share:	$	0.76	$	(0.19	)
Diluted income (loss) earnings per share:	$	0.75	$	(0.19	)

The dilutive impact summarized above relates to the periods when the average market price of Company 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. There were

48,067

options outstanding as of

August 31, 2017

that were dilutive.

170,887

shares of common stock were excluded from the computation as of

August 31, 2016

because the effect was anti-dilutive due to the Company’s net loss for fiscal

2016.

Note 11 - Stock-based Compensation

12 Months Ended

Aug. 31, 2017

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

11.

STOCK-BASED COMPENSATION

The Company has

two

stock-based compensation plans under which stock options and other stock-based awards have been granted, the Northern Technologies International Corporation Amended and Restated

2007

Stock Incentive Plan (the

2007

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 administer 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

ten

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. The Company issues new shares upon the exercise of options. As of

August 31, 2017,

only stock options and stock bonuses had 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 issued

3,029

and

2,438

shares of common stock on

September 1, 2016

and

2015,

respectively, under the ESPP. The Company issued

1,098

and

3,144

shares on

March 1, 2017

and

2016,

respectively, under the ESPP.

The fair value of option grants is determined at date of grant, using the Black-Scholes option pricing model with the assumptions listed below. The volatility factor used in the Black-Scholes option pricing model is based on historical stock price fluctuations and the risk-free interest rate is based on U.S. treasury rates appropriate for the expected term. Dividend yield and expected volatility are estimated using historical amounts that are anticipated to be consistent with current values. Expected life of the option is based on the life of the option agreements. Based on these valuations, the Company recognized compensation expense of

$391,664

and

$427,437

during fiscal

2017

and fiscal

2016,

respectively, related to the options that vested during such time period. As of

August

31,

2017,

the total compensation cost for non-vested options

not

yet recognized in the Company’s consolidated statements of operations was

$239,400.

Stock-based compensation expense of

$159,600

and

$79,800

is expected to be recognized during fiscal

2018

and

2019,

respectively, based on outstanding options as of

August 31, 2017.

Future option grants will impact the compensation expense recognized. Stock-based compensation expense is included in general and administrative expense on the consolidated statements of operations.

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:

	August 31, 2017			August 31, 2016
Dividend yield		0.00	%		0.00	%
Expected volatility		46.0	%		46.6	%
Expected life of option (years)		10			10
Weighted average risk-free interest rate		1.63	%		1.63	%

Stock option activity during the periods indicated is as follows:

	Number of Shares (#)			Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at August 31, 2015		241,734		$	13.72
Options granted		53,447			14.85
Options exercised		0			0.00
Options terminated		(12,000	)		13.38

Outstanding at August 31, 2016		283,181			13.95
Options granted		56,677			13.40
Options exercised		(12,000	)		10.25
Options terminated		(20,000	)		15.21

Outstanding at August 31, 2017		307,858		$	13.93	$	1,238,009

Exercisable at August 31, 2017		221,027		$	13.76	$	942,314

The weighted average per share fair value of options granted during fiscal

2017

and fiscal

2016

was

$7.69

and

$8.48,

respectively. The weighted average remaining contractual life of the total options and exercisable options outstanding as of

August 31, 2017

and

2016,

was

6.77

years and

6.46

years, respectively.

Note 12 - Segment and Geographic Information

12 Months Ended

Aug. 31, 2017

Segment Reporting Disclosure [Text Block]

12.

SEGMENT AND GEOGRAPHIC INFORMATION

Segment Information

The Company’s chief operating decision maker (CODM) is its Chief Executive Officer. The Company’s business is organized into

two

reportable segments: ZERUST

and Natur-Tec

. The Company has been selling its proprietary ZERUST

rust and corrosion inhibiting products and services to the automotive, electronics, electrical, mechanical, military and retail consumer markets for over

years, and more recently, has targeted and expanded into the oil and gas industry. The Company also sells a portfolio of bio-based and compostable (fully biodegradable) polymer resin compounds and finished products under the Natur-Tec

brand.

The following tables present the Company’s business segment information in fiscal

2017

and fiscal

2016:

	Fiscal 2017		Fiscal 2016
ZERUST ® net sales	$	32,789,283	$	27,577,566
Natur-Tec ® net sales		6,779,840		5,355,999
Total net sales	$	39,569,123	$	32,933,565

The following table sets forth the Company’s cost of goods sold for fiscal

2017

and fiscal

2016

by segment:

	Fiscal 2017		Fiscal 2016
Direct cost of goods sold
ZERUST®	$	18,996,264	$	15,588,133
Natur-Tec®		4,925,061		4,076,249
Indirect cost of goods sold		2,395,186		2,655,774
Total net cost of goods sold	$	26,316,511	$	22,320,156

The Company 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.

All joint venture operations including equity in income, fees for services and related dividends are related to ZERUST

products and services.

Geographic Information

Net sales by geographic location were as follows:

	Fiscal Year Ended August 31,
	2017		2016
Inside the U.S.A. to unaffiliated customers	$	21,787,694	$	20,304,480
Outside the U.S.A. to:
Joint ventures in which the Company is a shareholder directly and indirectly		3,222,478		2,721,905
Unaffiliated customers		14,558,951		9,907,180
	$	39,569,123	$	32,933,565

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 fiscal

2017

and fiscal

2016,

respectively, were as follows:

	Fiscal 2017		Fiscal 2016
Germany	$	838,628	$	845,857
Poland		661,226		599,391
Japan		641,699		646,015
Sweden		472,819		265,745
Thailand		448,013		537,212
France		410,842		329,805
South Korea		376,002		352,393
India		322,677		300,506
Czech		314,834		237,062
United Kingdom		295,761		386,761
Finland		292,225		252,578
Other		377,962		384,385
	$	5,452,687	$	5,137,710

Sales to the Company’s joint ventures are included in the foregoing segment and geographic information; however, sales by the Company’s joint ventures to other parties are

not

included. The foregoing segment and geographic information represents only sales and cost of goods sold recognized directly by the Company.

See Note

for additional details on geographical information regarding equity in income from joint ventures.

The geographical distribution of total long-lived assets and net sales is as follows:

	At August 31, 2017		At August 31, 2016
China	$	228,458	$	253,931
Brazil		54,646		66,938
Germany		14,171		—
India		14,712		13,645
United States		7,047,675		8,219,955
Total long-lived assets	$	7,359,662	$	8,554,469

	Fiscal Year Ended August 31, 2017		Fiscal Year Ended August 31, 2016
China	$	7,225,659	$	4,114,288
Brazil		2,394,730		2,172,297
Germany		711,923		—
India		1,417,955		1,104,947
Other		6,031,162		5,237,553
United States		21,787,694		20,304,480
Total net sales	$	39,569,123	$	32,933,565

Total long-lived assets located in China, Brazil, Germany and India consist of property and equipment. 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.

Sales to the Company’s joint ventures are included in the foregoing segment and geographic information; however, sales by the Company’s joint ventures to other parties are

not

included. The foregoing segment and geographic information represents only sales recognized directly by the Company.

All joint venture operations including equity in income, fees for services and related dividends are related to ZERUST

products and services.

Note 15 - Income Taxes

12 Months Ended

Aug. 31, 2017

Income Tax Disclosure [Text Block]

15.

INCOME TAXES

The provision for income taxes for the fiscal years ended

August

31,

2017

and

2016

consists of the following:

	Fiscal Year Ended August 31,
	2017			2016
Current:
Federal	$	—		$	—
State		62,000			20,000
Foreign		754,000			647,000
		816,000			667,000
Deferred:
Federal		(135,000	)		6,000
State		(9,000	)		—
Foreign		28,000			(47,000	)
		(116,000	)		(41,000	)
	$	700,000		$	626,000

Reconciliations of the expected federal income tax at the statutory rate with the provisions for income taxes for the fiscal years ended

August 31, 2017

and

2016

are as follows:

	Fiscal Year Ended August 31,
	2017			2016
Tax computed at statutory rates	$	1,591,000		$	(195,000	)
State income tax, net of federal benefit		53,000			20,000
Tax effect on equity in income of international joint ventures		(1,998,000	)		(956,000	)
Tax effect on dividends received from joint ventures and investment at carrying value		3,159,000			2,681,000
Tax effect of foreign operations		841,000			997,000
Foreign tax credit		(3,680,000	)		(3,178,000	)
Research and development credit		(212,000	)		(408,000	)
Valuation allowance		989,000			1,620,000
Stock based compensation		81,000			90,000
Non-controlling interest		(143,000	)		(148,000	)
Other		19,000			103,000
	$	700,000		$	626,000

The Company has

not

provided U.S. income taxes or foreign withholding taxes with respect to its portion of the cumulative undistributed earnings of foreign joint ventures that are essentially permanent in duration. The Company’s portion of the cumulative undistributed earnings of foreign joint ventures that are essentially permanent in duration were

$17,960,860

and

$17,779,912

as of

August 31, 2017

and

2016,

respectively. During fiscal

2016,

the Company recorded deferred income tax expense of

$3,000

representing foreign withholding taxes to be paid with respect to the portion of the cumulative undistributed earnings of foreign joint ventures that it determined were

not

essentially permanent in duration. If some or all of the undistributed earnings of the joint ventures are remitted to the Company in the future, income taxes, if any, after the application of foreign tax credits will be provided at that time. To the extent undistributed earnings of the Company’s joint ventures are distributed in the future, it is

not

expected to result in any material additional U.S. income tax liability after the application of foreign tax credits.

The tax effect of the temporary differences and tax carryforwards comprising the net deferred taxes shown on the consolidated balance sheets as of

August

31,

2017

and

2016

are as follows:

	August 31,
	2017			2016
Accrued compensation	$	310,300		$	150,600
Inventory costs		87,000			95,300
Accrued joint venture expenses		15,200			54,200
Other accrued expenses		74,000			87,000
Goodwill and other intangible assets		1,317,700			1,332,000
Stock-based compensation		241,600			210,600
Foreign tax credit carryforward		6,105,700			5,679,000
Other credit and loss carryforwards		3,473,100			3,214,300
Total deferred tax assets		11,624,600			10,823,000
Valuation allowance		(9,578,700	)		(8,893,300	)
Total deferred tax assets after valuation allowance		2,045,900			1,929,700
Property and equipment		(206,000	)		(215,600	)
Other		(83,300	)		(74,300	)
Total deferred tax liabilities		(289,300	)		(289,900	)
Net deferred tax assets	$	1,756,600		$	1,639,800

As of

August 31, 2017

the Company had foreign tax credit carryforwards of approximately

$6,105,700

which will begin to expire if

not

utilized prior to

August 31, 2021.

In addition, the Company had federal and state tax credit carryforwards of

$2,855,100

as of

August 31, 2017

which begin to expire in fiscal

2019.

These federal and state tax credit carryforwards consist primarily of federal and Minnesota research and development credit carryforwards. The Company also has foreign net operating loss carryforwards of

$618,000

as of

August 31, 2017

which begin to expire in fiscal

2020.

As of

August 31, 2017,

the Company has recorded a valuation allowance of

$6,105,700

with respect to the foreign tax credit carryforwards. In addition, the Company has recorded a valuation allowance of

$2,855,100

with respect to federal and state tax credit carryforwards, and has recorded a valuation allowance of

$618,000

with respect to the foreign net operating loss carryforwards.

As of

August 31, 2016,

the Company had recorded a valuation allowance of

$5,679,000

with respect to the foreign tax credit carryforwards. In addition, the Company had recorded a valuation allowance of

$2,643,300

with respect to federal and state tax credit carryforwards, and had recorded a valuation allowance of

$571,000

with respect to the foreign net operating loss carryforwards.

The Company records a tax valuation allowance to reduce deferred tax assets to the amount expected to be realized when it is more likely than

not

that some portion or all of its deferred tax assets will

not

be realized. The Company determined based on all available evidence, including historical data and projections of future results, that it is more likely than

not

that all of its deferred tax assets, except for its foreign tax credit carryforward, federal and Minnesota research and development credit carryforwards, and foreign net operating loss carryforwards will be fully realized. The Company determined that its deferred tax asset related to foreign tax credit carryforwards will

not

be realized due to insufficient federal taxable income within the carryforward period and the fact that for ordering purposes the foreign tax credit carryforwards are

not

allowed to be utilized until after any current year foreign tax credits are utilized. In addition, based on historical data and future projections, the Company determined that it is more likely than

not

that its deferred tax asset related to federal and Minnesota research and development credit carryforwards will

not

be realized due to insufficient federal and Minnesota taxable income within the carryforward period after considering the foreign tax credit usage. The Company determined that its deferred tax asset related to foreign net operating loss carryforwards will

not

be utilized due to insufficient taxable income within the carryforward period.

The following is a tabular reconciliation of the total amounts of unrecognized tax benefits:

	Fiscal Year Ended August 31,
	2017			2016
Gross unrecognized tax benefits – beginning balance	$	238,000		$	203,000
Gross increases (decreases) - prior period tax positions		(4,000	)		15,000
Gross increases – current period tax positions		16,000			20,000
Gross unrecognized tax benefits – ending balance	$	250,000		$	238,000

The entire amount of unrecognized tax benefits would affect the effective tax rate. It is

not

expected that the amount of unrecognized tax benefits will change significantly in the next

months.

The Company recognizes interest and penalties related to unrecognized tax benefits as a component of the Company’s income tax provision. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheet. There was

liability for the payment of interest and penalties as of both

August 31, 2017

and

August 31, 2016.

The Company is subject to taxation in the United States and various states and foreign jurisdictions. With few exceptions, as of

August 31, 2017,

the Company is

longer subject to federal, state, local, or foreign examinations by tax authorities for years prior to

August 31, 2014.

Note 16 - Commitments and Contingencies

12 Months Ended

Aug. 31, 2017

Commitments and Contingencies Disclosure [Text Block]

16.

COMMITMENTS AND CONTINGENCIES

August 31, 2017,

the Compensation Committee of the Board of Directors of the Company approved the material terms of an annual bonus plan for the Company’s executive officers as well as certain officers and employees for the fiscal year ending

August 31, 2018.

For fiscal

2018

as in past years, the total amount available under the bonus plan for all plan participants, including executive officers, is dependent upon 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). Each plan participant’s percentage of the overall bonus pool is based upon the number of plan participants, the individual’s annual base salary and the individual’s position and level of responsibility within the company. In the case of each of the Company’s executive officer participants,

75%

of the amount of their individual bonus payout will be determined based upon the Company’s actual EBITOI for fiscal

2018

compared to a pre-established target EBITOI for fiscal

2018

and

25%

of the payout will be determined based upon such executive officer’s achievement of certain pre-established 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 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

2018.

August 26, 2016,

August 31, 2017.

For fiscal

2017

as in past years, the total amount available under the bonus plan for all plan participants, including executive officers, is dependent upon the Company’s Adjusted EBITOI. Each plan participant’s percentage of the overall bonus pool is based upon the number of plan participants, the individual’s annual base salary and the individual’s position and level of responsibility within the company. In the case of each of the Company’s executive officer participants,

75%

of the amount of their individual bonus payout will be determined based upon the Company’s actual EBITOI for fiscal

2017

compared to a pre-established target EBITOI for fiscal

2017

and

25%

may

2017.

Accrued bonuses as of

August 31, 2017

and

2016

were

$1,015,000

and

$450,000,

respectively.

Three joint ventures (consisting of the Company’s joint ventures in South Korea, Thailand and India) accounted for

60.7%

of the Company’s trade joint venture receivables as of

August 31, 2017,

and

three

joint ventures (consisting of the Company’s joint ventures in South Korea, India and Thailand) accounted for

55.8%

of the Company’s trade joint venture receivables as of

August 31, 2016.

March 23, 2015,

NTIC and NTI Asean LLC, a majority-owned subsidiary of NTIC, filed a lawsuit in Tianjin

Intermediate People’s Court against

two

individuals, Tao Meng and Xu Hui, related to breaches of duties and contractual commitments owed to NTI Asean under certain agreements related to NTIC’s former joint venture in China, Tianjin Zerust Anti-Corrosion Technologies Ltd. The lawsuit alleges, among other things, that Mr. Tao Meng and Xu Hui have engaged in self-dealing, usurped business opportunities, and received economic benefits that were required to go to Tianjin Zerust. At this point it is too early in the lawsuit to reasonably estimate the amount of any recovery to NTI Asean.

April 21, 2015,

NTIC and NTI Asean initiated a lawsuit against Cortec Corporation alleging, among other things, that Cortec Corporation (Cortec) aided and abetted breaches of duties and contractual commitments owed to NTIC and NTI Asean related to NTIC’s joint venture in China, Tianjin Zerust. On

September 20, 2017,

following a jury trial that commenced on

September 18, 2017,

the United States District Court for the Northern District of Ohio dismissed with prejudice all claims asserted by the Company in the lawsuit. The Company chose

not

to appeal the Court’s dismissal of the case.

From time to time, the Company is subject to various other claims and legal actions in the ordinary course of its business. The Company records a liability in its consolidated financial statements for costs related to claims, including future legal costs, settlements and judgments, where the Company has assessed that a loss is probable and an amount could be reasonably estimated. If the reasonable estimate of a probable loss is a range, the Company records the most probable estimate of the loss or the minimum amount when

amount within the range is a better estimate than any other amount. The Company discloses a contingent liability even if the liability is

not

probable or the amount is

not

estimable, or both, if there is a reasonable possibility that material loss

may

be have been incurred. In the opinion of management, as of

August 31, 2017,

the amount of liability, if any, with respect to these matters, individually or in the aggregate, will

not

materially affect the Company’s consolidated results of operations, financial position or cash flows.

The Company has leases for office and warehouse space in the United States of America, China, India, Germany and Brazil with monthly rents ranging from

$814

$11,539,

which expire through

August 31, 2023.

Future minimum rents due under these leases are as follows for each of the next

five

years ended

August 31:

Fiscal 2018	$	264,919
Fiscal 2019		146,635
Fiscal 2020		109,209
Fiscal 2021		66,647
Fiscal 2022		67,133
Thereafter		47,884
	$	702,427

Note 18 - Fair Value Measurements

12 Months Ended

Aug. 31, 2017

Fair Value, Measurement Inputs, Disclosure [Text Block]

18.

Fair Value Measurements

The Company follows the authoritative guidance on fair value measurements and disclosures with respect to assets and liabilities that are measured at fair value on both a recurring and non-recurring basis. Under this guidance, fair value is defined as the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The authoritative guidance also establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use in valuing the asset or liability, developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors market participants would use in valuing the asset or liability developed based upon the best information available in the circumstances. The categorization of financial assets and financial liabilities within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

The hierarchy is broken down into

three

levels defined as follows:

Level 1 -		Inputs are quoted prices in active markets for identical assets or liabilities.
Level 2 -		Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs (other than quoted prices) that are observable for the asset or liability, either directly or indirectly.
Level 3 -		Inputs are unobservable for the asset or liability.

See the section below titled Valuation Techniques for further discussion of how the Company determines fair value for investments.

Assets and Liabilities That Are Measured at Fair Value on a Recurring Basis

Assets and liabilities that are measured at fair value on a recurring basis primarily relate to marketable equity securities. These items are marked-to-market at each reporting period.

The following tables provide information by level for assets and liabilities that are measured at fair value on a recurring basis:

			Fair Value Measurements Using Inputs Considered as
	Fair value as of August 31, 2017		Level 1		Level 2		Level 3
Available for sale securities	$	3,766,984	$	3,766,984	$	—	$	—

			Fair Value Measurements Using Inputs Considered as
	Fair value as of August 31, 2016		Level 1		Level 2		Level 3
Available for sale securities	$	2,243,864	$	2,243,864	$	—	$	—

Valuation Techniques

Financial assets that are classified as Level

securities include cash equivalents and available for sale securities. These are valued using quoted market prices in an active market.

The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs

may

result in a reclassification of levels for certain securities within the fair value hierarchy. The Company’s policy is to recognize transfers into and out of levels within the fair value hierarchy at the end of the fiscal quarter in which the actual event or change in circumstances that caused the transfer occurs. There were

transfers between Level

Level

or Level

during the fiscal years ended

August 31, 2017

August 31, 2016.

When a determination is made to classify an asset or liability within Level

the determination is based upon the significance of the unobservable inputs to the overall fair value measurement.

Significant Accounting Policies (Policies)

12 Months Ended

Aug. 31, 2017

Accounting Policies [Abstract]

Consolidation, Policy [Policy Text Block]

Principles of Consolidation

not

include the accounts of any of its joint ventures.

Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]

Non-Controlling Interests

– The Company owns

90%

of Natur-Tec India,

85%

of Zerust Brazil and

60%

Revenue Recognition, Deferred Revenue [Policy Text Block]

Net Sales

–The Company includes net sales to its joint ventures and net sales to unaffiliated customers as separate line items on its consolidated statements of operations. There are

sales originating from the Company’s joint ventures included in the amount, as the Company’s investments in its joint ventures are accounted for using the equity method.

Revenue Recognition

Receivables, Policy [Policy Text Block]

Trade Receivable

days. The Company does

not

$40,000

as of

August 31, 2017

and

2016.

Receivables from Joint Ventures Policy [Policy Text Block ]

Trade Receivables from Joint Ventures

days are considered past due. The Company does

not

necessary as of

August 31, 2017

2016.

Fees for Services Provided to Joint Ventures –

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash and Cash Equivalents

- The Company includes as cash and cash equivalents highly liquid, short-term investments with maturity of

three

months or less when purchased, which are readily convertible into known amounts of cash. The Company maintains its cash in high quality financial institutions. The balances, at times,

may

exceed federally insured limits.

Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block]

Available for Sale Securities

– Available for sale securities are recorded at fair value. Unrealized holding gains and losses on available for sale securities are excluded from earnings.

Inventory, Policy [Policy Text Block]

Inventories

- Inventories are recorded at the lower of cost (

first

-in,

first

-out basis) or market.

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Depreciation

- Property and equipment are stated at cost. Depreciation is computed using the straight-line method based on the estimated service lives of the various assets as follows:

Buildings and improvements (years)		5	-	30
Machinery and equipment (years)		3	-	10

Intangible Assets, Finite-Lived, Policy [Policy Text Block]

Patents and Trademarks

Equity Method Investments [Policy Text Block]

Investments in Joint Ventures

zero

value until proportionate income exceeds the losses. The Company assesses its joint ventures for impairment on an annual basis as of

August 31

not

may

differ from assumed or estimated amounts. All investments in joint ventures have positive equity as of

August 31, 2017

and

2016.

The Company considers any of its joint ventures to be significant and discloses entity specific financial information if the joint venture’s income or assets make up more than

20%

of the Company’s total assets or income.

Investment at Carrying Value

– If the Company is

longer exists and discontinues accruing the proportionate earnings or losses of the investment.

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Recoverability of Long-Lived Assets

- The Company reviews its long-lived assets whenever events or changes in circumstances indicate the carrying amount of the assets

may

not

Income Tax, Policy [Policy Text Block]

Income Taxes

The Company records net deferred tax assets to the extent the Company believes these assets will more likely than

not

The Company records uncertain tax positions on the basis of a

two

-step process whereby the Company determines whether it is more likely than

not

that the tax positions will be sustained based on the technical merits of the position and those tax positions that meet the more-likely-than-

not

recognition threshold. The Company recognizes the largest amount of tax benefit that is greater than

percent likely to be realized upon ultimate settlement with the related tax authority.

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign Currency Translation (Accumulated Other Comprehensive Income (Loss))

not

change the equity in income from joint ventures reflected in the Company’s consolidated statements of operations.

Fair Value of Financial Instruments, Policy [Policy Text Block]

Fair Value of Financial Instruments

Shipping and Handling Cost, Policy [Policy Text Block]

Shipping and Handling

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

Research and Development

- The Company expenses all costs related to product research and development as incurred.

Stockholders' Equity, Policy [Policy Text Block]

Common Stock

– The Company issues authorized but unissued shares of common stock upon the exercise of stock options.

Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]

Stock-Based Compensation

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

Note 3 - Inventories (Tables)

12 Months Ended

Aug. 31, 2017

Schedule of Inventory, Current [Table Text Block]

	August 31, 2017		August 31, 2016
Production materials	$	1,747,189	$	1,452,396
Finished goods		5,709,636		6,258,891
	$	7,456,552	$	7,711,287

Note 6 - Investments in Joint Ventures (Tables)

12 Months Ended

Aug. 31, 2017

Condensed Balance Sheet [Table Text Block]

	As of August 31, 2017
	Total		EXCOR		All Other
Current assets	$	51,518,210	$	22,142,514	$	29,375,696
Total assets		55,633,891		24,301,194		31,332,697
Current liabilities		15,118,074		4,469,567		10,648,507
Noncurrent liabilities		181,210		—		181,210
Joint ventures’ equity		40,334,607		19,831,627		20,502,980
Northern Technologies International Corporation’s share of joint ventures’ equity		20,035,074		9,915,816		10,119,258
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	17,960,860	$	9,884,911	$	8,075,949

	As of August 31, 2016
	Total		EXCOR		All Other
Current assets	$	48,922,924	$	22,928,810	$	25,994,114
Total assets		52,407,026		24,733,340		27,673,686
Current liabilities		12,433,700		3,485,231		8,948,469
Noncurrent liabilities		100,783		—		100,783
Joint ventures’ equity		39,872,543		21,248,109		18,624,434
Northern Technologies International Corporation’s share of joint ventures’ equity		19,840,774		10,624,056		9,216,728
Northern Technologies International Corporation's share of joint ventures’ undistributed earnings	$	17,779,912	$	10,593,151	$	7,186,761

Condensed Income Statement [Table Text Block]

	Fiscal Year Ended August 31, 2017
	Total		EXCOR		All Other
Net sales	$	101,261,132	$	39,849,757	$	61,411,375
Gross profit		44,861,300		21,133,632		23,727,668
Net income		11,839,933		8,369,728		3,470,205
Northern Technologies International Corporation’s share of equity in income of joint ventures		5,898,908		4,185,988		1,712,920
Northern Technologies International Corporation's dividends received from joint ventures	$	6,377,054	$	5,379,062	$	997,992

	Fiscal Year Ended August 31, 2016
	Total		EXCOR		All Other
Net sales	$	90,646,833	$	35,138,214	$	55,508,619
Gross profit		40,440,726		18,635,421		21,805,305
Net income		9,534,771		7,049,462		2,485,309
Northern Technologies International Corporation’s share of equity in income from joint ventures		4,743,831		3,534,113		1,209,718
Northern Technologies International Corporation’s dividends received from joint ventures	$	5,503,314	$	4,364,700	$	1,165,614

Note 11 - Stock-based Compensation (Tables)

12 Months Ended

Aug. 31, 2017

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	August 31, 2017			August 31, 2016
Dividend yield		0.00	%		0.00	%
Expected volatility		46.0	%		46.6	%
Expected life of option (years)		10			10
Weighted average risk-free interest rate		1.63	%		1.63	%

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of Shares (#)			Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at August 31, 2015		241,734		$	13.72
Options granted		53,447			14.85
Options exercised		0			0.00
Options terminated		(12,000	)		13.38

Outstanding at August 31, 2016		283,181			13.95
Options granted		56,677			13.40
Options exercised		(12,000	)		10.25
Options terminated		(20,000	)		15.21

Outstanding at August 31, 2017		307,858		$	13.93	$	1,238,009

Exercisable at August 31, 2017		221,027		$	13.76	$	942,314

Note 12 - Segment and Geographic Information (Tables)

12 Months Ended

Aug. 31, 2017

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

	Fiscal 2017		Fiscal 2016
ZERUST ® net sales	$	32,789,283	$	27,577,566
Natur-Tec ® net sales		6,779,840		5,355,999
Total net sales	$	39,569,123	$	32,933,565

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

	Fiscal 2017		Fiscal 2016
Direct cost of goods sold
ZERUST®	$	18,996,264	$	15,588,133
Natur-Tec®		4,925,061		4,076,249
Indirect cost of goods sold		2,395,186		2,655,774
Total net cost of goods sold	$	26,316,511	$	22,320,156

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

	Fiscal Year Ended August 31,
	2017		2016
Inside the U.S.A. to unaffiliated customers	$	21,787,694	$	20,304,480
Outside the U.S.A. to:
Joint ventures in which the Company is a shareholder directly and indirectly		3,222,478		2,721,905
Unaffiliated customers		14,558,951		9,907,180
	$	39,569,123	$	32,933,565

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

	At August 31, 2017		At August 31, 2016
China	$	228,458	$	253,931
Brazil		54,646		66,938
Germany		14,171		—
India		14,712		13,645
United States		7,047,675		8,219,955
Total long-lived assets	$	7,359,662	$	8,554,469

Revenue from External Customers by Geographic Areas [Table Text Block]

	Fiscal Year Ended August 31, 2017		Fiscal Year Ended August 31, 2016
China	$	7,225,659	$	4,114,288
Brazil		2,394,730		2,172,297
Germany		711,923		—
India		1,417,955		1,104,947
Other		6,031,162		5,237,553
United States		21,787,694		20,304,480
Total net sales	$	39,569,123	$	32,933,565

Fees for Services Provided to Joint Ventures [Member]

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

	Fiscal 2017		Fiscal 2016
Germany	$	838,628	$	845,857
Poland		661,226		599,391
Japan		641,699		646,015
Sweden		472,819		265,745
Thailand		448,013		537,212
France		410,842		329,805
South Korea		376,002		352,393
India		322,677		300,506
Czech		314,834		237,062
United Kingdom		295,761		386,761
Finland		292,225		252,578
Other		377,962		384,385
	$	5,452,687	$	5,137,710

Note 15 - Income Taxes (Tables)

12 Months Ended

Aug. 31, 2017

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Fiscal Year Ended August 31,
	2017			2016
Current:
Federal	$	—		$	—
State		62,000			20,000
Foreign		754,000			647,000
		816,000			667,000
Deferred:
Federal		(135,000	)		6,000
State		(9,000	)		—
Foreign		28,000			(47,000	)
		(116,000	)		(41,000	)
	$	700,000		$	626,000

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Fiscal Year Ended August 31,
	2017			2016
Tax computed at statutory rates	$	1,591,000		$	(195,000	)
State income tax, net of federal benefit		53,000			20,000
Tax effect on equity in income of international joint ventures		(1,998,000	)		(956,000	)
Tax effect on dividends received from joint ventures and investment at carrying value		3,159,000			2,681,000
Tax effect of foreign operations		841,000			997,000
Foreign tax credit		(3,680,000	)		(3,178,000	)
Research and development credit		(212,000	)		(408,000	)
Valuation allowance		989,000			1,620,000
Stock based compensation		81,000			90,000
Non-controlling interest		(143,000	)		(148,000	)
Other		19,000			103,000
	$	700,000		$	626,000

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	August 31,
	2017			2016
Accrued compensation	$	310,300		$	150,600
Inventory costs		87,000			95,300
Accrued joint venture expenses		15,200			54,200
Other accrued expenses		74,000			87,000
Goodwill and other intangible assets		1,317,700			1,332,000
Stock-based compensation		241,600			210,600
Foreign tax credit carryforward		6,105,700			5,679,000
Other credit and loss carryforwards		3,473,100			3,214,300
Total deferred tax assets		11,624,600			10,823,000
Valuation allowance		(9,578,700	)		(8,893,300	)
Total deferred tax assets after valuation allowance		2,045,900			1,929,700
Property and equipment		(206,000	)		(215,600	)
Other		(83,300	)		(74,300	)
Total deferred tax liabilities		(289,300	)		(289,900	)
Net deferred tax assets	$	1,756,600		$	1,639,800

Summary of Income Tax Contingencies [Table Text Block]

	Fiscal Year Ended August 31,
	2017			2016
Gross unrecognized tax benefits – beginning balance	$	238,000		$	203,000
Gross increases (decreases) - prior period tax positions		(4,000	)		15,000
Gross increases – current period tax positions		16,000			20,000
Gross unrecognized tax benefits – ending balance	$	250,000		$	238,000

Note 1 - Nature of Business and Significant Accounting Policies (Details Textual)	12 Months Ended
	Aug. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
Number of Countries in which Entity Operates	60
Number of Operating Segments	2
Number of Joint Venture Arrangements	20
Allowance for Doubtful Accounts Receivable	$ 40,000	$ 40,000
NaturTec [Member]
Noncontrolling Interest, Ownership Percentage by Parent	90.00%
Zerust Brazil [Member]
Noncontrolling Interest, Ownership Percentage by Parent	85.00%
NTI Asean LLC [Member]
Noncontrolling Interest, Ownership Percentage by Parent	60.00%
Maximum [Member]
Noncontrolling Interest, Ownership Percentage by Parent	50.00%

Note 3 - Inventories - Inventories (Details) - USD ($)	Aug. 31, 2017	Aug. 31, 2016
Production materials	$ 1,747,189	$ 1,452,396
Finished goods	5,709,636	6,258,891
Total inventory	$ 7,456,552	$ 7,711,287

Note 4 - Property and Equipment, Net - Components of Property and Equipment, Net (Details) - USD ($)	Aug. 31, 2017	Aug. 31, 2016
Land	$ 310,365	$ 310,365
Buildings and improvements	6,847,177	6,528,252
Machinery and equipment	4,171,387	3,590,063
Gross	11,328,929	10,428,680
Less accumulated depreciation	(3,969,267)	(3,152,808)
Net	$ 7,359,662	$ 7,275,872

Note 5 - Patents and Trademarks, Net (Details Textual) - USD ($)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Amortization	$ 119,033	$ 119,032
Patents and Trademarks [Member]
Finite-Lived Intangible Asset, Useful Life	7 years
Amortization	$ 119,033	$ 119,032
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	120,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	120,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	120,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	120,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	$ 120,000

Note 5 - Patents and Trademarks, Net - Patents and Trademarks, Net (Details) - USD ($)	Aug. 31, 2017	Aug. 31, 2016
Patents and trademarkes, net	$ 1,322,089	$ 1,278,597
Patents and Trademarks [Member]
Patents and trademarks	2,737,959	2,575,435
Less accumulated amortization	(1,415,870)	(1,296,838)
Patents and trademarkes, net	$ 1,322,089	$ 1,278,597

Note 6 - Investments in Joint Ventures - Condensed Balance Sheet of EXCOR and All Other Joint Ventures (Details) - USD ($)	Aug. 31, 2017	Aug. 31, 2016
Current assets	$ 51,518,210	$ 48,922,924
Total assets	55,633,891	52,407,026
Current liabilities	15,118,074	12,433,700
Noncurrent liabilities	181,210	100,783
Joint ventures’ equity	40,334,607	39,872,543
Northern Technologies International Corporation’s share of joint ventures’ equity	20,035,074	19,840,774
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	17,960,860	17,779,912
EXCOR [Member]
Current assets	22,142,514	22,928,810
Total assets	24,301,194	24,733,340
Current liabilities	4,469,567	3,485,231
Noncurrent liabilities
Joint ventures’ equity	19,831,627	21,248,109
Northern Technologies International Corporation’s share of joint ventures’ equity	9,915,816	10,624,056
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	9,884,911	10,593,151
Joint Venture in India [Member]
Current assets	29,375,696	25,994,114
Total assets	31,332,697	27,673,686
Current liabilities	10,648,507	8,948,469
Noncurrent liabilities	181,210	100,783
Joint ventures’ equity	20,502,980	18,624,434
Northern Technologies International Corporation’s share of joint ventures’ equity	10,119,258	9,216,728
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$ 8,075,949	$ 7,186,761

Note 6 - Investments in Joint Ventures - Condensed Income Statement of EXCOR and All Other Joint Ventures (Details) - USD ($)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Net sales	$ 101,261,132	$ 90,646,833
Gross profit	44,861,300	40,440,726
Net income	11,839,933	9,534,771
Northern Technologies International Corporation’s share of equity in income of joint ventures	5,898,908	4,743,831
Northern Technologies International Corporation's dividends received from joint ventures	6,377,054	5,503,314
EXCOR [Member]
Net sales	39,849,757	35,138,214
Gross profit	21,133,632	18,635,421
Net income	8,369,728	7,049,462
Northern Technologies International Corporation’s share of equity in income of joint ventures	4,185,988	3,534,113
Northern Technologies International Corporation's dividends received from joint ventures	5,379,062	4,364,700
Joint Venture in India [Member]
Net sales	61,411,375	55,508,619
Gross profit	23,727,668	21,805,305
Net income	3,470,205	2,485,309
Northern Technologies International Corporation’s share of equity in income of joint ventures	1,712,920	1,209,718
Northern Technologies International Corporation's dividends received from joint ventures	$ 997,992	$ 1,165,614

Note 8 - Corporate Debt (Details Textual)	12 Months Ended
Note 8 - Corporate Debt (Details Textual)	Aug. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
Term Loan and Line of Credit, Agreements, Loan Agreements [Member]
Debt Instrument, Covenants, Fixed Charge Coverage Ratio	1.1
PNC Bank [Member]
Letters of Credit Outstanding, Amount	$ 0	$ 0
PNC Bank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	3,000,000
Long-term Line of Credit	$ 0	$ 0
PNC Bank [Member] \| Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	2.15%
PNC Bank [Member] \| Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,200,000
JP Morgan Chase Bank [Member]
Letters of Credit Outstanding, Amount	$ 89,543

Note 9 - Stockholders' Equity (Details Textual) - USD ($)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Jan. 15, 2015
Stock Repurchase Program, Authorized Amount			$ 3,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 2,640,548
Stock Repurchased and Retired During Period, Shares	14,525
Treasury Stock Acquired, Average Cost Per Share	$ 13.51
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	12,000	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 10.25	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	56,677	53,447
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 13.40	$ 14.85
The 2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	56,677	53,447
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 13.40	$ 14.85

Note 10 - Net Income (Loss) Per Common Share - Reconciliation of the Earnings Per Share Computations (Details) - USD ($)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Net income (loss) attributable to NTIC	$ 3,422,126	$ (867,514)
Basic-weighted shares outstanding (in shares)	4,528,611	4,537,504
Weighted shares assumed upon exercise of stock options (in shares)	48,748
Diluted – weighted shares outstanding (in shares)	4,577,359	4,537,504
Basic income (loss) earnings per share: (in dollars per share)	$ 0.76	$ (0.19)
Diluted income (loss) earnings per share: (in dollars per share)	$ 0.75	$ (0.19)

Note 11 - Stock-based Compensation (Details Textual)					12 Months Ended
Note 11 - Stock-based Compensation (Details Textual)	Mar. 01, 2017 shares	Sep. 01, 2016 shares	Mar. 01, 2016 shares	Sep. 01, 2015 shares	Aug. 31, 2017 USD ($) $ / shares shares	Aug. 31, 2016 USD ($) $ / shares
Number of Stock-based Compensation Plans					2
Stock Issued During Period, Shares, Employee Stock Purchase Plans \| shares	1,098	3,029	3,144	2,438
Stock or Unit Option Plan Expense					$ 391,664	$ 427,437
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options					239,400
Allocated Share-based Compensation Expense, Estimate, Next Fiscal Year					159,600
Allocated Share-based Compensation Expense, Estimate, Fiscal Year Two					$ 79,800
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value \| $ / shares					$ 7.69	$ 8.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term					6 years 281 days	6 years 167 days
The 2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized \| shares					800,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period					10 years
The 2007 Plan [Member] \| One Year after Date of Grant [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					3 years
The 2007 Plan [Member] \| One Year after Date of Grant [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					4 years
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized \| shares					100,000
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent					90.00%

Note 11 - Stock-based Compensation - Black-Scholes Option-pricing Model Assumptions (Details)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Dividend yield	0.00%	0.00%
Expected volatility	46.00%	46.60%
Expected life of option (Year)	10 years	10 years
Weighted average risk-free interest rate	1.63%	1.63%

Note 11- Stock-based Compensation - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Number of shares, Outstanding (in shares)	283,181	241,734
Weighted average exercise price, Outstanding (in dollars per share)	$ 13.95	$ 13.72
Number of shares, Options granted (in shares)	56,677	53,447
Weighted average exercise price, Options granted (in dollars per share)	$ 13.40	$ 14.85
Number of shares, Options exercised (in shares)	(12,000)	0
Weighted average exercise price, Options exercised (in dollars per share)	$ 10.25	$ 0
Number of shares, Options terminated (in shares)	(20,000)	(12,000)
Weighted average exercise price, Options terminated (in dollars per share)	$ 15.21	$ 13.38
Number of shares, Outstanding (in shares)	307,858	283,181
Weighted average exercise price, Outstanding (in dollars per share)	$ 13.93	$ 13.95
Aggregate intrinsic value, Outstanding	$ 1,238,009
Number of shares, Exercisable (in shares)	221,027
Weighted average exercise price, Exercisable (in dollars per share)	$ 13.76
Aggregate intrinsic value, Exercisable	$ 942,314

Note 12 - Segment and Geographic Information - Cost of Goods Sold by Segment (Details) - USD ($)

12 Months Ended

Aug. 31, 2017

Aug. 31, 2016

$ 26,316,511

$ 22,320,156

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

^[1]

22320156.00%

18,996,264

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

^[1]

15588133.00%

4,925,061

Indirect Cost of Goods Sold [Member]

^[1]

4076249.00%

$ 2,395,186