Fair Value Measurement (Assets Remeasured At Fair Value On Non-Recurring Basis) (Details) (Non-Recurring, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2013	Jul. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss, REO	$ (353)	$ (261)
Loss, Impaired mortgage loans held for investment	(1,390)	(4,337)
Total, Gain (loss) on financial instruments	(1,743)	(4,598)
Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	14,752	16,384
Impaired mortgage loans held for investment	76,699	93,666
Total financial assets at fair value	91,451	110,050
As a percentage of total assets	2.40%	3.10%
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	0	0
Impaired mortgage loans held for investment	0	0
Total financial assets at fair value	0	0
As a percentage of total assets	0.00%	0.00%
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	0	0
Impaired mortgage loans held for investment	0	0
Total financial assets at fair value	0	0
As a percentage of total assets	0.00%	0.00%
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	14,752	16,384
Impaired mortgage loans held for investment	76,699	93,666
Total financial assets at fair value	$ 91,451	$ 110,050
As a percentage of total assets	2.40%	3.10%