Valuation (Schedule Of Significant Unobservable Inputs, Qualitative Information) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Securitized debt	$ 983,000		$ 983,000
Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	694,403,000		756,934,000
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage Backed Securities And Commercial Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	33,214,000		34,489,000
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage Backed Securities And Commercial Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	14.25		14.25
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage Backed Securities And Commercial Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	99.50		102.89
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage Backed Securities And Commercial Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	68.31		74.24
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities, Other asset-backed securities, and Securitized Debt [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	475,211,000	[1]	550,701,000	[2]
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities, Other asset-backed securities, and Securitized Debt [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	1.79	[1]	1.80	[2]
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities, Other asset-backed securities, and Securitized Debt [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	110.11	[1]	110.35	[2]
Level 3 [Member] | Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities, Other asset-backed securities, and Securitized Debt [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	77.94	[1]	78.09	[2]
Level 3 [Member] | Market Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	40,018,000		38,783,000
Level 3 [Member] | Market Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	6.13		6.26
Level 3 [Member] | Market Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	22.65		33.77
Level 3 [Member] | Market Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Indicative Price	14.19		14.53
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Residential Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	61,348,000		67,158,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Residential Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	3.50%		3.80%
Projected Collateral Prepayments	7.40%		6.90%
Projected Collateral Losses	1.40%		4.30%
Projected Collateral Recoveries	0.00%		0.30%
Projected Collateral Scheduled Amortization	0.00%		14.10%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Residential Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	23.90%		20.50%
Projected Collateral Prepayments	86.80%		64.50%
Projected Collateral Losses	44.20%		35.20%
Projected Collateral Recoveries	24.80%		17.10%
Projected Collateral Scheduled Amortization	84.80%		87.30%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Residential Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	7.90%		8.00%
Projected Collateral Prepayments	34.40%		29.70%
Projected Collateral Losses	14.50%		17.40%
Projected Collateral Recoveries	7.60%		9.10%
Projected Collateral Scheduled Amortization	43.50%		43.80%
Total Outstanding Collateral	100.00%		100.00%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	4,405,000		3,480,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	9.70%		9.20%
Projected Collateral Losses	0.20%		0.20%
Projected Collateral Recoveries	1.90%		15.40%
Projected Collateral Scheduled Amortization	85.60%		84.40%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	24.90%		18.20%
Projected Collateral Losses	2.40%		0.20%
Projected Collateral Recoveries	12.00%		15.40%
Projected Collateral Scheduled Amortization	97.80%		84.40%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	14.70%		13.50%
Projected Collateral Losses	1.20%		0.20%
Projected Collateral Recoveries	6.60%		15.40%
Projected Collateral Scheduled Amortization	92.20%		84.40%
Total Outstanding Collateral	100.00%		100.00%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	19,000,000		8,788,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	12.70%		12.70%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	15.00%		12.80%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	13.90%		12.70%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	20,030,000		10,123,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	10.40%		15.00%
Months to Resolution	7 months		5 months
Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	19.70%		15.00%
Months to Resolution	17 months		7 months
Level 3 [Member] | Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	17.70%		15.00%
Months to Resolution	10 months		6 months
Level 3 [Member] | Income Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	1,357,000		1,721,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	60.10%		49.00%
Projected Collateral Scheduled Amortization	24.10%		41.90%
LIBOR OAS	7.54%	[3]	3.49%	[3]
Level 3 [Member] | Income Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	75.90%		58.10%
Projected Collateral Scheduled Amortization	39.90%		51.00%
LIBOR OAS	10.32%	[3]	6.45%	[3]
Level 3 [Member] | Income Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	66.60%		51.20%
Projected Collateral Scheduled Amortization	33.40%		48.80%
LIBOR OAS	9.17%	[3]	4.22%	[3]
Total Outstanding Collateral	100.00%		100.00%
Level 3 [Member] | Income Approach Valuation Technique [Member] | Residential Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	23,663,000		24,062,000
Level 3 [Member] | Income Approach Valuation Technique [Member] | Residential Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	6.80%		7.40%
Months to Resolution	4 months 24 days		16 months 9 days
Level 3 [Member] | Income Approach Valuation Technique [Member] | Residential Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	7.10%		7.40%
Months to Resolution	16 months 3 days		16 months 9 days
Level 3 [Member] | Income Approach Valuation Technique [Member] | Residential Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	7.10%		7.40%
Months to Resolution	9 months 6 days		16 months 9 days
Credit Default Swaps On Asset Backed Securities [Member] | Level 3 [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 14,824,000		$ 16,296,000
Credit Default Swaps On Asset Backed Securities [Member] | Level 3 [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	19.20%		19.30%
Projected Collateral Losses	16.10%		15.50%
Projected Collateral Recoveries	8.30%		8.20%
Projected Collateral Scheduled Amortization	15.40%		15.70%
Credit Default Swaps On Asset Backed Securities [Member] | Level 3 [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	56.80%		59.00%
Projected Collateral Losses	49.40%		47.80%
Projected Collateral Recoveries	15.40%		15.20%
Projected Collateral Scheduled Amortization	41.70%		41.20%
Credit Default Swaps On Asset Backed Securities [Member] | Level 3 [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	29.60%		29.90%
Projected Collateral Losses	34.20%		34.80%
Projected Collateral Recoveries	13.30%		13.10%
Projected Collateral Scheduled Amortization	22.90%		22.20%
Total Outstanding Collateral	100.00%		100.00%

[1] Includes securitized debt with a fair value of $1.0 million as of March 31, 2014.

[2] Includes securitized debt with a fair value of $1.0 million as of December 31, 2013.

[3] Shown in basis points.