Mortgage Loans Held For Investment And Related Assets (Schedule Of Portfolio Balance) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2012	Apr. 30, 2011
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	$ 516,509	$ 572,974
Related Allowance	89,949	92,087
Pooled (Less Than 60 Days Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	260,916	304,325
Related Allowance	9,467	11,238
Individually (TDRs) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	84,443	106,328
Related Allowance	9,011	11,056
Individually (60 Days Or More Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	171,150	162,321
Related Allowance	$ 71,471	$ 69,793