Fair Value Measurement (Quantitative Information About Level 3 Fair Value Measurements) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014
Market Approach Valuation Technique [Member] | Minimum | Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	5.00%
Loss severity	0.00%
Market Approach Valuation Technique [Member] | Maximum | Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	57.00%
Loss severity	100.00%
Market Approach Valuation Technique [Member] | Weighted Average | Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	6.00%
Loss severity	49.00%
Collateral-Based | Impaired Mortgage Loans Held For Investment - Non TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Time to sell (in months)	24 years
Collateral-Based | Impaired Mortgage Loans Held For Investment - TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 39,519
Collateral-Based | Minimum | Impaired Mortgage Loans Held For Investment - Non TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	0.00%
Loss severity	0.00%
Collateral depreciation	(166.00%)
Collateral-Based | Maximum | Impaired Mortgage Loans Held For Investment - Non TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	185.00%
Loss severity	100.00%
Collateral depreciation	100.00%
Collateral-Based | Weighted Average | Impaired Mortgage Loans Held For Investment - Non TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Cost to list/sell	9.00%
Loss severity	64.00%
Time to sell (in months)	24 months
Collateral depreciation	50.00%
Discounted Cash Flow | Impaired Mortgage Loans Held For Investment - Non TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 72,644
Discounted Cash Flow | Minimum | Impaired Mortgage Loans Held For Investment - TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss severity	0.00%
Aged default performance	24.00%
Discounted Cash Flow | Maximum | Impaired Mortgage Loans Held For Investment - TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss severity	22.00%
Aged default performance	39.00%
Discounted Cash Flow | Weighted Average | Impaired Mortgage Loans Held For Investment - TDRs
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss severity	6.00%
Aged default performance	32.00%