Quarterly Financial Data (Summary Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 2,327,915	$ 451,882	$ 131,332	$ 125,185	$ 2,297,477	$ 474,543	$ 128,415	$ 137,718	$ 3,036,314	$ 3,038,153	$ 3,078,658
Income (loss) from continuing operations before taxes (benefit)	1,211,903	(150,598)	(228,469)	(203,549)	1,140,807	(146,500)	(237,719)	(187,109)	629,287	569,479	742,805
Income taxes (benefit)	425,333	(49,386)	(85,054)	(82,523)	439,582	(67,851)	(95,201)	(90,604)	208,370	185,926	256,061
Net income (loss) from continuing operations	786,570	(101,212)	(143,415)	(121,026)	701,225	(78,649)	(142,518)	(96,505)	420,917	383,553	486,744
Net loss from discontinued operations, net of tax benefits of $6,986, $5,414 and $8,125	(3,218)	(3,302)	(2,805)	(2,647)	(563)	(3,080)	(2,489)	(3,154)	(11,972)	(9,286)	(13,081)
NET INCOME	$ 783,352	$ (104,514)	$ (146,220)	$ (123,673)	$ 700,662	$ (81,729)	$ (145,007)	$ (99,659)	$ 408,945	$ 374,267	$ 473,663
Continuing operations (in usd per share	$ 3.79	$ (0.49)	$ (0.67)	$ (0.55)	$ 3.15	$ (0.34)	$ (0.54)	$ (0.35)	$ 1.97	$ 1.54	$ 1.77
Discontinued operations (in usd per share)	(0.02)	(0.01)	(0.01)	(0.01)	0.00	(0.01)	(0.01)	(0.01)	(0.05)	(0.04)	(0.05)
Consolidated (in usd per share)	3.77	(0.50)	(0.68)	(0.56)	3.15	(0.35)	(0.55)	(0.36)	1.92	1.50	1.72
Continuing operations (in usd per share)	3.76	(0.49)	(0.67)	(0.55)	3.13	(0.34)	(0.54)	(0.35)	1.96	1.53	1.75
Discontinued operations (in usd per share)	(0.01)	(0.01)	(0.01)	(0.01)	0.00	(0.01)	(0.01)	(0.01)	(0.05)	(0.04)	(0.04)
Consolidated (in usd per share)	$ 3.75	$ (0.50)	$ (0.68)	$ (0.56)	$ 3.13	$ (0.35)	$ (0.55)	$ (0.36)	$ 1.91	$ 1.49	$ 1.71
Goodwill impairments									$ 0	$ 0