Retirement Plans, Recent Plan Curtailments (Details)	12 Months Ended
	Apr. 30, 2022
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee retirement age limit under retirement plans	60 years
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee retirement age limit under retirement plans	65 years
Supplemental Executive Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Term of supplemental retirement benefits	10 years