Product Warranties (Tables)

12 Months Ended

Apr. 30, 2021

Product Warranties Disclosures [Abstract]

Schedule of Product Warranty Liability [Table Text Block]

As of April 30, 2021 and 2020, respectively, changes in the carrying amount of accrued product warranty costs, reported in accrued expenses on the consolidated balance sheets, were as follows (in thousands):

	2021			2020
Balance at beginning of year	$	527		$	529
Warranty costs incurred		(619	)		(293	)
Product warranty accrual		531			291
Balance at end of year	$	439		$	527