Fair Value Measurements - Reconciliation (Details) - Significant unobservable inputs (Level 3) $ in Thousands	12 Months Ended
Apr. 30, 2020 USD ($)
Reconciliation between beginning and ending balances of items measured at fair value on recurring basis
Business acquisition	$ 1,703
Settlements	(2,500)
Cost of sales
Reconciliation between beginning and ending balances of items measured at fair value on recurring basis
Included in earnings	1,147
SG&A
Reconciliation between beginning and ending balances of items measured at fair value on recurring basis
Included in earnings	(703)
Reseach and development
Reconciliation between beginning and ending balances of items measured at fair value on recurring basis
Included in earnings	$ 353

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

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