Employee Benefit and Retirement Plans (Reconciliation Of Benefit Obligations, Plan Assets, And Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Retirement Benefits [Abstract]
Projected benefit obligation at beginning of year	$ 191,184	$ 168,788
Interest cost	4,662	5,974	$ 6,269
Acturial (gains) and losses	6,759	22,293
Benefits paid	(6,068)	(5,871)
Projected benefit obligation at end of year	196,537	191,184	168,788
Fair value of plan assets at beginning of year	190,743	169,471
Actual return on plan assets	8,877	26,674
Company contributions	0	469
Benefits paid	(6,068)	(5,871)
Fair value of plan assets at end of year	193,552	190,743	$ 169,471
Funded status of the plan	$ (2,985)	$ (441)