Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Apr. 30, 2012
Income Tax Disclosure [Abstract]
Accrued expenses	$ 15,842	$ 21,533
Allowance for credit losses and related reserves	114,570	102,819
Capital loss carryover	45,826	0
Valuation allowance	(28,088)	(33,672)
Current	148,150	90,680
Deferred and stock-based compensation	20,758	23,590
Deferred revenue	30,225	26,181
Net operating loss carry-forward	20,070	18,202
State tax benefits related to federal unrecognized tax benefits	30,374	31,824
Capital loss carryover	2,379	85,778
Other	3,901	2,901
Valuation allowance	(26,525)	(43,771)
Noncurrent	81,182	144,705
Deferred tax asset	229,332	235,385
Prepaid expenses	(2,830)	(3,641)
Current	(2,830)	(3,641)
Property and equipment	(25,794)	(19,454)
Mortgage-related investment	(20,033)	(63,115)
Intangibles	(36,565)	(33,935)
Noncurrent	(82,392)	(116,504)
Net deferred tax assets	$ 144,110	$ 115,240