Mortgage Loans Held For Investment And Related Assets (Schedule Of Portfolio Balance And Related Allowance) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Apr. 30, 2012
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	$ 405,670	$ 429,312
Related Allowance	22,185	26,540
Pooled [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	238,999	248,772
Related Allowance	7,701	9,237
Individually (TDRs) [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	67,587	71,949
Related Allowance	6,931	7,752
Individually [Member]
Mortgage Loans Held For Investment And Related Assets [Line Items]
Portfolio Balance	99,084	108,591
Related Allowance	$ 7,553	$ 9,551