Note 6 - Impairment of Long-lived Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Apr. 30, 2023	Dec. 31, 2016
Impairment, Long-Lived Asset, Held-for-Use, Total	$ 0
Goodwill, Impairment Loss	$ 0
Perma-Pipe Canada, Ltd [Member]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage		50.00%

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
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-Section 45
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration