Quarterly Financial Data (Summary Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 2,297,477	$ 474,543	$ 128,415	$ 137,718	$ 2,301,370	$ 509,074	$ 134,628	$ 133,586	$ 3,038,153	$ 3,078,658	$ 3,024,295
Income (loss) from continuing operations before taxes (benefit)	1,140,807	(146,500)	(237,719)	(187,109)	1,210,059	(90,865)	(200,573)	(175,816)	569,479	742,805	767,116
Income taxes (benefit)	439,582	(67,851)	(95,201)	(90,604)	465,926	(55,554)	(87,346)	(66,965)	185,926	256,061	267,019
Net income (loss) from continuing operations	701,225	(78,649)	(142,518)	(96,505)	744,133	(35,311)	(113,227)	(108,851)	383,553	486,744	500,097
Net loss from discontinued operations, net of tax benefits of $5,414, $8,125 and $15,422	(563)	(3,080)	(2,489)	(3,154)	(5,292)	(1,637)	1,229	(7,381)	(9,286)	(13,081)	(24,940)
NET INCOME	$ 700,662	$ (81,729)	$ (145,007)	$ (99,659)	$ 738,841	$ (36,948)	$ (111,998)	$ (116,232)	$ 374,267	$ 473,663	$ 475,157
Continuing operations (in usd per share	$ 3.15	$ (0.34)	$ (0.54)	$ (0.35)	$ 2.70	$ (0.13)	$ (0.41)	$ (0.40)	$ 1.54	$ 1.77	$ 1.82
Discontinued operations (in usd per share)	0.00	(0.01)	(0.01)	(0.01)	(0.02)	0.00	0.00	(0.02)	(0.04)	(0.05)	(0.09)
Consolidated (in usd per share)	3.15	(0.35)	(0.55)	(0.36)	2.68	(0.13)	(0.41)	(0.42)	1.50	1.72	1.73
Continuing operations (in usd per share)	3.13	(0.34)	(0.54)	(0.35)	2.68	(0.13)	(0.41)	(0.40)	1.53	1.75	1.81
Discontinued operations (in usd per share)	0.00	(0.01)	(0.01)	(0.01)	(0.02)	0.00	0.00	(0.02)	(0.04)	(0.04)	(0.09)
Consolidated (in usd per share)	$ 3.13	$ (0.35)	$ (0.55)	$ (0.36)	$ 2.66	$ (0.13)	$ (0.41)	$ (0.42)	$ 1.49	$ 1.71	$ 1.72
Goodwill impairments									$ 0	$ 0