Fair Value Measurement (Assets Remeasured At Fair Value On Non-Recurring Basis) (Details) (Non-Recurring [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss, REO	$ (693)	$ (1,920)
Loss, Impaired mortgage loans held for investment	(10,235)	(11,390)
Total, Gain (loss) on financial instruments	(10,928)	(13,310)
Total [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	15,870	12,366
Impaired mortgage loans held for investment	99,974	90,628
Total financial assets at fair value	115,844	102,994
As a percentage of total assets	2.50%	1.90%
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO
Impaired mortgage loans held for investment
Total financial assets at fair value
As a percentage of total assets
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO
Impaired mortgage loans held for investment
Total financial assets at fair value
As a percentage of total assets
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	15,870	12,366
Impaired mortgage loans held for investment	99,974	90,628
Total financial assets at fair value	$ 115,844	$ 102,994
As a percentage of total assets	2.50%	1.90%