Fair Value Measurement Fair Value Of Financial Instruments (Summary Of Carrying Amounts And Estimated Fair Values Of Company's Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash and cash equivalents, Carrying Amount	$ 2,185,307	$ 1,747,584	$ 1,944,334	$ 1,677,844
Cash and cash equivalents, Estimated Fair Value	2,185,307	1,747,584
Cash and cash equivalents - restricted, Carrying Amount	115,319	117,837
Cash and cash equivalents - restricted, Estimated Fair Value	115,319	117,837
Receivables, net - short-term, Carrying Amount	191,618	206,835
Receivables, net - short-term, Estimated Fair Value	191,618	206,810
Mortgage loans held for investment, less allowance for loan losses of $11,272 and $14,314	268,428	338,789
Mortgage loans held for investment, net, Estimated Fair Value	192,281	210,858
Investments in available-for-sale securities, Carrying Amount	4,329	486,876
Investments in available-for-sale securities, Estimated Fair Value	427,824	486,876
Receivables, net - long-term, Carrying Amount	104,678	125,048
Receivables, net - long-term, Estimated Fair Value	104,678	134,283
Deposits, Carrying Amount	770,288	938,331
Deposits, Estimated Fair Value	765,376	934,019
Long-term borrowings, Carrying Amount	906,474	906,680
Long-term borrowings, Estimated Fair Value	955,050	964,630
Contingent acquisition liabilities, Carrying Amount	9,206	11,277
Cusiness Combination, Contingent Consideration, at Fair Value	$ 9,206	$ 11,277