Minimum amount required for invoices received.

No definition available.

Name:	intt_MinimumAmountRequiredForInvoicesReceived
Namespace Prefix:	intt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
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-Paragraph 4
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

+ Details

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

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

+ Details

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

- Definition

Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147479613/805-30-35-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479668/805-30-25-6

+ Details

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

- Definition

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479613/805-30-35-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479668/805-30-25-6

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=intt_AcculogicMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=intt_PaymentsBasedOnPerformanceMetricsMember
Namespace Prefix:
Data Type:	na
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Period Type:

Note 4 - Fair Value Measurements (Details Textual) $ in Thousands, $ in Millions		9 Months Ended
	Dec. 21, 2021 CAD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 21, 2021 USD ($)	Dec. 21, 2021 CAD ($)
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability		$ 0	$ (358)
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Other Current Liabilities [Member]
Business Combination, Contingent Consideration, Liability, Current		197		$ 0
Acculogic [Member]
Business Combination, Contingent Consideration, Liability		1,020		1,093
Acculogic [Member] \| Fair Value, Inputs, Level 3 [Member]
Business Combination, Contingent Consideration, Liability		1,020		$ 1,093
Acculogic [Member] \| Payments Based on Performance Metrics [Member] \| Fair Value, Recurring [Member]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		3,697				$ 5.0
Minimum Amount Required for Invoices Received	$ 2.5
Business Combination, Contingent Consideration, Liability					$ 1,430
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability		$ 50