Employee Benefit and Retirement Plans (Schedule Of Pension Assets By Major Category Of Plan Assets And Type Of Fair Value Measurements) (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	$ 193,552	$ 190,743
QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	193,552	190,743
SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	80,524	490
Cash and Cash Equivalents [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	80,524	490
Cash and Cash Equivalents [Member] | SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
Cash and Cash Equivalents [Member] | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
Mutual Fund Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		37,569
Mutual Fund Equity [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		37,569
Mutual Fund Equity [Member] | SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		0
Mutual Fund Equity [Member] | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		0
International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		24,578
International Equity [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value		24,578
Mutual Fund Income Tax [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	113,028	128,106
Mutual Fund Income Tax [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	113,028	128,106
Mutual Fund Income Tax [Member] | SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
Mutual Fund Income Tax [Member] | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	$ 0	$ 0