Mortgage Loans Held For Investment And Related Assets (Schedule Of Portfolio Balance And Related Allowance) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Apr. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Balance	$ 372,139	$ 429,312
Related Allowance	17,256	26,540
Pooled [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Balance	219,345	248,772
Related Allowance	6,670	9,237
Individually (TDRs) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Balance	59,295	71,949
Related Allowance	5,013	7,752
Individually [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Balance	93,499	108,591
Related Allowance	$ 5,573	$ 9,551