Defined contribution plan employer matching contribution vesting period.

No definition available.

Name:	intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod
Namespace Prefix:	intt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum dollar amount of employer's annual matching contribution to a defined contribution plan

+ References

No definition available.

+ Details

Name:	intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmployeeAmount
Namespace Prefix:	intt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationLiabilityClassifiedNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
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:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum amount the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanNameAxis=intt_The401KPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=intt_TheAmbrellPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 13 - Employee Benefit Plans (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Deferred Compensation Liability, Classified, Noncurrent	$ 1,473		$ 1,473
401(k) Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay			10.00%
Defined Contribution Plan Maximum Annual Employer Matching Contribution Per Employee Amount			$ 5
Defined Contribution Plan Employer Matching Contribution Vesting Period (Year)			4 years
The Ambrell Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay			10.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent			100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			50.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount			$ 5
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 97	$ 100	$ 705	$ 671