Employee Benefit and Retirement Plans (Schedule Of Assumptions Used To Determine Benenfit Obligations And Earnings Effects For Pension Plans) (Details)	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.12%	4.06%
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.06%	4.19%	4.56%
Expected return on plan assets	7.50%	7.50%	7.50%