Mortgage Loans Held For Investment And Related Assets (Schedule Of Portfolio Balance) (Details) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2011	Apr. 30, 2011
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio balance	$ 537,754	$ 572,974
Related allowance	91,379	92,087
Pooled (Less Than 60 Days Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio balance	276,447	304,325
Related allowance	10,076	11,238
Individually (TDRs) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio balance	89,351	106,328
Related allowance	8,576	11,056
Individually (60 Days Or More Past Due) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio balance	171,956	162,321
Related allowance	$ 72,727	$ 69,793