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Intangibles (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
Intangibles (Details) - USD ($)	Oct. 26, 2019	Oct. 27, 2018	Oct. 26, 2019	Oct. 27, 2018	Apr. 30, 2019
Intangibles
Intangibles, gross	$ 18,590,000		$ 18,590,000		$ 1,770,000
Less accumulated amortization	(2,638,000)		(2,638,000)		(1,311,000)
Intangibles, net	15,952,000		$ 15,952,000		$ 459,000
Weighted average amortization period			5 years		1 year
Amortization expense	775,000	$ 80,000	$ 1,327,000	$ 149,000
Technology
Intangibles
Intangibles, gross	14,950,000		14,950,000
In process research and development
Intangibles
Intangibles, gross	1,370,000		1,370,000
Licenses
Intangibles
Intangibles, gross	1,006,000		1,006,000		$ 1,006,000
Customer relationships
Intangibles
Intangibles, gross	873,000		873,000		733,000
Non-compete agreements
Intangibles
Intangibles, gross	320,000		320,000
Trademarks and tradenames
Intangibles
Intangibles, gross	68,000		68,000		28,000
Other
Intangibles
Intangibles, gross	$ 3,000		$ 3,000		$ 3,000