Customer Receivables (Components Of Customer Receivables) (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Receivables [Abstract]
Gross customer receivables	$ 112,528	$ 132,145
Allowance for doubtful accounts	(472)	(249)
Allowance for returns and discounts	(5,712)	(5,995)
Net customer receivables	$ 106,344	$ 125,901

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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