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, 2013	Apr. 30, 2012	Apr. 30, 2011
Income Tax Disclosure [Abstract]
Federal, Current	$ 219,411	$ 126,773	$ 171,337
State, Current	43,116	21,285	40,433
Foreign, Current	3,173	8,647	21,456
Current income tax expense (benefit)	265,700	156,705	233,226
Federal, Deferred	(29,258)	55,032	(1,762)
State, Deferred	(69)	18,154	3,404
Foreign, Deferred	480	211	288
Deferred taxes	(28,847)	73,397	1,930
Total income taxes for continuing operations	$ 236,853	$ 230,102	$ 235,156