Mortgage Loans Held For Investment And Related Assets (Schedule Of Allowance For Impaired Loans) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Apr. 30, 2012
Mortgage Loans Held For Investment And Related Assets [Abstract]
Based on collateral value method	$ 7,553	$ 9,551
Based on discounted cash flow method	6,931	7,752
Total allowance for loans	$ 14,484	$ 17,303