Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit) For Continuing Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Income Tax Disclosure [Abstract]
Document Fiscal Year Focus									2017
Federal, Current									$ 147,961	$ 167,233	$ 245,473
State, Current									15,118	(26,980)	31,501
Foreign, Current									10,678	8,735	9,788
Current income tax expense (benefit)									173,757	148,988	286,762
Federal, Deferred									39,299	19,937	(30,181)
State, Deferred									(5,064)	13,801	(4,040)
Foreign, Deferred									378	3,200	3,520
Deferred taxes									34,613	36,938	(30,701)
Total income taxes for continuing operations	$ 425,333	$ (49,386)	$ (85,054)	$ (82,523)	$ 439,582	$ (67,851)	$ (95,201)	$ (90,604)	$ 208,370	$ 185,926	$ 256,061