Mortgage Loans Held For Investment And Related Assets (Schedule Of Portfolio Balance And Related Allowance) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2012	Apr. 30, 2011
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	$ 429,312	$ 572,974
Related Allowance	26,540	92,087
Pooled (Less Than 60 Days Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	248,772	304,325
Related Allowance	9,237	11,238
Individually (TDRs) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	71,949	106,328
Related Allowance	7,752	11,056
Individually (60 Days Or More Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	108,591	162,321
Related Allowance	$ 9,551	$ 69,793