Percent Of Revenue From Contract With Customer, Excluding Assessed Tax

No definition available.

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130549-203045

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84173487&loc=SL51747714-108306

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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Revenue recognition (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
Revenue recognition (Details) - USD ($) $ in Thousands	Jul. 31, 2018	Apr. 30, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Disaggregation of Revenue [Line Items]
Sales by product	$ 32,325		$ 26,852	$ 61,214	$ 50,353
Sales by product (percent of total)	100.00%		100.00%	100.00%	100.00%
Revenue recognized that was included in contract liabilities	$ 422	$ 1,810
Products [Member]
Disaggregation of Revenue [Line Items]
Sales by product	$ 2,578		$ 1,995	$ 5,007	$ 3,326
Sales by product (percent of total)	8.00%		7.00%	8.00%	7.00%
Specialty Piping Systems And Coating [Member]
Disaggregation of Revenue [Line Items]
Sales by product (percent of total)	90.00%
Specialty Piping Systems And Coating [Member] \| Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Sales by product	$ 9,807		$ 14,138	$ 20,909	$ 23,254
Sales by product (percent of total)	30.00%		53.00%	34.00%	46.00%
Specialty Piping Systems And Coating [Member] \| Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Sales by product	$ 19,940		$ 10,719	$ 35,298	$ 23,773
Sales by product (percent of total)	62.00%		40.00%	58.00%	47.00%