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, 2019	Apr. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	$ 169,471	$ 156,463
QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	169,471	156,463
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	469	448
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	469	448
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	31,143	37,421
Mutual Fund Equity [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	31,143	37,421
Mutual Fund Equity [Member] | SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
Mutual Fund Equity [Member] | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0	0
International Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	20,553	25,135
International Equity [Member] | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	20,553	25,135
International Equity [Member] | SIGNIFICANT OBSERVABLE INPUTS (LEVEL 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	0
International Equity [Member] | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value
Mutual Fund Income Tax [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets at net asset value	117,306	93,459
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	117,306	93,459
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