Note 15 - Retirement Plan (Details Textual) - USD ($)	12 Months Ended
Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	15.00%
Defined Contribution Plan Maximum Amount of Employees Contributions Percent	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.50%
Defined Contribution Plan, Cost Recognized	$ 214,008	$ 188,207	$ 175,016

Maximum percentage employer matches of the employee's percentage contribution matched.

No definition available.

Name:	ntic_DefinedContributionPlanMaximumAmountOfEmployeesContributionsPercent
Namespace Prefix:	ntic_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration