Fair Value Measurement (Assets Remeasured At Fair Value On Non-Recurring Basis) (Details) (Non-Recurring [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss), REO	$ (261)	$ (482)
Gain (loss), Impaired mortgage loans held for investment	(4,337)	(1,473)
Total, Gain (loss) on financial instruments	(4,598)	(1,955)
Total [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	16,384	3,446
Impaired mortgage loans held for investment	93,666	61,997
Total financial assets at fair value	110,050	65,443
As a percentage of total assets	3.10%	1.50%
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	16,384	3,446
Impaired mortgage loans held for investment	93,666	61,997
Total financial assets at fair value	$ 110,050	$ 65,443
As a percentage of total assets	3.10%	1.50%