Investments - Unrealized Gains and Losses and Fair Value (Details) - USD ($) $ in Thousands	Jul. 27, 2019	Apr. 27, 2019
Summary of investments
Gross Unrealized Gains	$ 2,545	$ 2,174
Gross Unrealized Losses	(63)	(124)
Fair Value	62,458	57,421
Equity securities
Summary of investments
Gross Unrealized Gains	2,066	1,841
Fair Value	23,268	19,535
Fixed income
Summary of investments
Gross Unrealized Gains	155	75
Gross Unrealized Losses	(47)	(111)
Fair Value	34,382	33,217
Other
Summary of investments
Gross Unrealized Gains	324	258
Gross Unrealized Losses	(16)	(13)
Fair Value	$ 4,808	$ 4,669