Mortgage Loans Held for Investment and Related Assets (Information Related to Activities of Non-Performing Assets) (Details) (USD $) In Thousands	12 Months Ended
	Apr. 30, 2011	Apr. 30, 2010	Apr. 30, 2009
Average impaired loans	$ 289,755	$ 307,351	$ 216,391
Interest income on impaired loans	6,624	8,548	5,964
Interest income on impaired loans recognized on a cash basis on non-accrual status	6,311	7,452	4,927
Purchased from SCC [Member]
Average impaired loans	252,673
Interest income on impaired loans	5,795
Interest income on impaired loans recognized on a cash basis on non-accrual status	5,567
All Other [Member]
Average impaired loans	37,082
Interest income on impaired loans	829
Interest income on impaired loans recognized on a cash basis on non-accrual status	$ 744