Mortgage Loans Held For Investment And Related Assets (Information Related To Impaired Loans) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Apr. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance With Allowance	$ 45,695	$ 63,265
Balance With No Allowance	107,099	117,275
Total Impairment Loans	152,794	180,540
Related Allowance	10,586	17,303
Purchased From SCC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance With Allowance	38,938	56,128
Balance With No Allowance	88,671	97,591
Total Impairment Loans	127,609	153,719
Related Allowance	8,470	14,917
All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance With Allowance	6,757	7,137
Balance With No Allowance	18,428	19,684
Total Impairment Loans	25,185	26,821
Related Allowance	$ 2,116	$ 2,386