Employee Benefit and Retirement Plans (Reconciliation Of Benefit Obligations, Plan Assets, And Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Retirement Benefits [Abstract]
Projected benefit obligation at beginning of year	$ 163,423	$ 165,173
Interest cost	6,269	5,727	$ 5,772
Acturial (gains) and losses	4,850	(2,596)
Benefits paid	(5,754)	(4,881)
Projected benefit obligation at end of year	168,788	163,423	165,173
Fair value of plan assets at beginning of year	156,463	137,141
Actual return on plan assets	11,479	4,884
Company contributions	7,283	19,319
Benefits paid	(5,754)	(4,881)
Fair value of plan assets at end of year	169,471	156,463	$ 137,141
Funded status of the plan	$ 683	$ (6,960)