Note 3 - Accounts Receivable (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
Apr. 30, 2022 USD ($)	Apr. 30, 2021	Jan. 31, 2022 USD ($)
Accounts Receivable, Outstanding for Several Years	$ 3,600		$ 3,600
Retention Receivable	3,400		$ 3,400
Allowance for Doubtful Accounts Receivable Outstanding for Several Years	$ 0
Revenue Benchmark [Member] \| Customer Concentration Risk [Member]
Number of Major Customers	0	0
Accounts Receivable [Member] \| Customer Concentration Risk [Member]
Number of Major Customers	2		1
Accounts Receivable [Member] \| Customer Concentration Risk [Member] \| Two Customers [Member]
Concentration Risk, Percentage	22.90%
Accounts Receivable [Member] \| Customer Concentration Risk [Member] \| One Customer [Member]
Concentration Risk, Percentage			11.90%
Other Noncurrent Assets [Member]
Retention Receivable	$ 1,400		$ 2,000

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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