Fair Value Measurement (Assets Remeasured At Fair Value On Non-Recurring Basis) (Details) (Non-Recurring, USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 31, 2014	Jan. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss, REO	$ (437)	$ (350)
Loss, Impaired mortgage loans held for investment	(4,022)	(8,509)
Total, Gain (loss) on financial instruments	(4,459)	(8,859)
Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
REO	8,723	14,683
Impaired mortgage loans held for investment	71,053	87,949
Total financial assets at fair value	79,776	102,632
As a percentage of total assets	2.30%	2.60%
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	8,723	14,683
Impaired mortgage loans held for investment	71,053	87,949
Total financial assets at fair value	$ 79,776	$ 102,632
As a percentage of total assets	2.30%	2.60%