Quantitative Information About Level 3 Fair Value Measurements - Default Assumptions (Details) - Retained Interest [Member]	12 Months Ended
	Dec. 31, 2015
Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	100.00%
Range Of Loss Timining	Next 10 Months
Real Estate Owned [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Real Estate Owned [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Real Estate Owned [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Loans In Foreclosure [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	100.00%
Range Of Loss Timining	Month 4 - 13
Loans In Foreclosure [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Loans In Foreclosure [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Loans In Foreclosure [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	41.60%
Loans 90 Days Delinquent [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	100.00%
Range Of Loss Timining	Month 11-28
Loans 90 Days Delinquent [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 90 Days Delinquent [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 90 Days Delinquent [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 60 Days Delinquent [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	85.00%
Range Of Loss Timining	Month 11-28
Loans 60 Days Delinquent [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 60 Days Delinquent [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 60 Days Delinquent [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 30 Days Delinquent [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	75.00%
Range Of Loss Timining	Month 11-28
Loans 30 Days Delinquent [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 30 Days Delinquent [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Loans 30 Days Delinquent [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Current Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Probability of Default	2.50%
Range Of Loss Timining	Month 29 and Beyond
Current Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Current Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%
Current Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loss Severity Range	45.00%