Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit) For Continuing Operations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
Income Taxes [Abstract]
Federal, Current	$ 126,773	$ 171,337	$ 95,473
State, Current	21,285	40,433	23,674
Foreign, Current	8,647	21,456	16,331
Current income tax expense (benefit)	156,705	233,226	135,478
Federal, Deferred	55,032	(1,762)	104,606
State, Deferred	18,154	3,404	28,035
Foreign, Deferred	211	288	172
Deferred taxes	73,397	1,930	132,813
Total income taxes for continuing operations	$ 230,102	$ 235,156	$ 268,291