Fair Value (Assets Remeasured At Fair Value On Non-Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Non-Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss, Impaired mortgage loans held for investment	$ (88)	$ (842)
Non-Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired mortgage loans held for investment	$ 0	$ 0
As a percentage of total assets	0.00%	0.00%
Non-Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired mortgage loans held for investment	$ 0	$ 0
As a percentage of total assets	0.00%	0.00%
Non-Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired mortgage loans held for investment	$ 57,951	$ 59,635
As a percentage of total assets	1.60%	1.50%
Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired mortgage loans held for investment	$ 57,951	$ 59,635
As a percentage of total assets	1.60%	1.50%