Income Taxes (Schedule Of Significant Components Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Apr. 30, 2018	Apr. 30, 2017
Deferred tax assets:
Pension benefits	$ 0	$ 8,852
Accounts receivable	4,772	6,938
Product liability	2,180	1,272
Employee benefits	6,513	7,914
Other	2,865	862
Gross deferred tax assets, before valuation allowance	20,267	29,921
Valuation allowance	(2,467)	(2,446)
Gross deferred tax assets, after valuation allowance	17,800	27,475
Deferred tax liabilities:
Pension benefits	1,035	0
Inventory	240	297
Depreciation	21,076	9,131
Intangibles	65,294	0
Other	986	0
Total	88,631	9,428
Net deferred tax liability	(70,831)
Net deferred tax asset		18,047
State [Member]
Deferred tax assets:
State tax credit carryforwards	$ 3,937	$ 4,083