Mortgage Loans Held For Investment And Related Assets (Information Related To Impaired Loans) (Details) (USD $) In Thousands	Jul. 31, 2011	Apr. 30, 2011
Portfolio balance	$ 263,229	$ 268,649
Related allowance	80,389	80,849
Purchased From SCC [Member] | Portfolio Balance With Allowance [Member]
Portfolio balance	180,494	180,387	[1]
All Other [Member] | Portfolio Balance With Allowance [Member]
Portfolio balance	27,954	29,027	[1]
Portfolio Balance With Allowance [Member]
Portfolio balance	208,448	209,414
Purchased From SCC [Member] | Portfolio Balance With No Allowance [Member]
Portfolio balance	47,081	51,674	[1]
All Other [Member] | Portfolio Balance With No Allowance [Member]
Portfolio balance	7,700	7,561	[1]
Portfolio Balance With No Allowance [Member]
Portfolio balance	54,781	59,235
Purchased From SCC [Member]
Portfolio balance	227,575	232,061	[1]
Related allowance	70,964	71,733	[1]
All Other [Member]
Portfolio balance	35,654	36,588	[1]
Related allowance	$ 9,425	$ 9,116	[1]

[1] Classification of amounts as of April 30, 2011 have been restated to conform to the current period presentation.