Mortgage Loans Held For Investment And Related Assets (Information Related To Activities Of Non-Performing Assets) (Details) (USD $) In Thousands	3 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Average impaired loans	$ 266,627	$ 303,767
Interest income on impaired loans	1,675	1,749
Interest income on impaired loans recognized on a cash basis on non-accrual status	1,612	1,636
Purchased From SCC [Member]
Average impaired loans	230,150
Interest income on impaired loans	1,556
Interest income on impaired loans recognized on a cash basis on non-accrual status	1,498
All Other [Member]
Average impaired loans	36,477
Interest income on impaired loans	119
Interest income on impaired loans recognized on a cash basis on non-accrual status	$ 114