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, unless otherwise specified	Apr. 30, 2014		Apr. 30, 2013		Apr. 30, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 102,599		$ 95,733		$ 85,717
Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	338		315
Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	102,261		95,418
Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	338		315
Cash and Cash Equivalents [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	338		315
Cash and Cash Equivalents [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Cash and Cash Equivalents [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Equity Index Value Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	20,753	[1]	19,202	[1]
Equity Index Value Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Equity Index Value Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	20,753	[1]	19,202	[1]
Equity Index Value Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Equity Index Growth Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	20,485	[1]	19,245	[1]
Equity Index Growth Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Equity Index Growth Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	20,485	[1]	19,245	[1]
Equity Index Growth Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Small Cap Index Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,929	[1]	5,632	[1]
Small Cap Index Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Small Cap Index Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,929	[1]	5,632	[1]
Small Cap Index Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
International Equity Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4,166	[1]	3,932	[1]
International Equity Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
International Equity Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4,166	[1]	3,932	[1]
International Equity Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Core Fixed Income Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33,409	[1]	30,000	[1]
Core Fixed Income Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Core Fixed Income Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33,409	[1]	30,000	[1]
Core Fixed Income Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Capital Preservation Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	17,519	[1]	17,407	[1]
Capital Preservation Fund [Member] | Fair Value Measurements Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Capital Preservation Fund [Member] | Fair Value Measurements Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	17,519	[1]	17,407	[1]
Capital Preservation Fund [Member] | Fair Value Measurements Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0	[1]	$ 0	[1]

[1] The Collective Trust Funds are valued by applying each plan's ownership percentage in the fund to the fund's net assets at fair value at the valuation date.