Income Taxes (Schedule Of Significant Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Income Taxes [Abstract]
Deferred tax assets. Pension benefits	$ 15,381	$ 20,563
Deferred tax assets, Accounts receivable	4,603	3,983
Deferred tax assets, Product liability	745	700
Deferred tax assets, Employee benefits	8,523	11,243
Deferred tax assets, Net operating loss carryforward	469	1,099
Deferred tax assets, Income tax credits	0	1,088
Deferred tax assets. Depreciation	0	73
Deferred Tax Assets, Other	199	496
Total	29,920	39,245
Deferred tax liabilities, Inventory	496	502
Deferred tax liabilities, Depreciation	2,374	0
Total	2,870	502
Net deferred tax asset	$ 27,050	$ 38,743