Valuation (Schedule Of Significant Unobservable Inputs, Qualitative Information) (Details) - Level 3 [Member]	12 Months Ended
	Dec. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)
Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 47,024,000		$ 89,549,000
Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	2.00		1.81
Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	101.02		151.86
Market Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	67.51		68.47
Market Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 37,517,000		$ 41,978,000
Market Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	9.42		13.00
Market Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	100.25		102.00
Market Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	83.36		84.84
Market Approach Valuation Technique [Member] | Corporate Debt and non-exchange traded corporate equity [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 19,017,000		$ 18,972,000
Market Approach Valuation Technique [Member] | Corporate Debt and non-exchange traded corporate equity [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	1.88		3.00
Market Approach Valuation Technique [Member] | Corporate Debt and non-exchange traded corporate equity [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	102.25		200.00
Market Approach Valuation Technique [Member] | Corporate Debt and non-exchange traded corporate equity [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	87.14		77.85
Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 27,283,000		$ 20,365,000
Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	5.17		6.07
Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	77.75		73.20
Market Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	40.88		41.28
Market Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 23,322,000		$ 21,067,000
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 Third-Party Valuation	2.47		2.97
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 Third-Party Valuation	20.17		22.41
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 Third-Party Valuation	11.65		11.08
Income Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 43,059,000		$ 26,886,000
Income Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	0.60%		3.40%
Projected Collateral Prepayments	0.00%		5.40%
Fair Value Inputs Losses	1.40%		2.90%
Fair Value Inputs Projected Collateral Recoveries	0.40%		0.30%
Fair Value Inputs Projected Collateral Scheduled Amortization	0.00%		8.60%
Income Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	20.50%		27.10%
Projected Collateral Prepayments	81.00%		74.60%
Fair Value Inputs Losses	51.20%		24.50%
Fair Value Inputs Projected Collateral Recoveries	53.60%		13.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	90.70%		88.60%
Income Approach Valuation Technique [Member] | Private Label Residential Mortgage Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	11.00%		19.90%
Projected Collateral Prepayments	10.00%		46.30%
Fair Value Inputs Losses	41.40%		11.40%
Fair Value Inputs Projected Collateral Recoveries	41.20%		8.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	7.40%		34.30%
Total Outstanding Collateral	100.00%		100.00%
Income Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 7,439,000		$ 3,996,000
Income Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	11.20%		8.30%
Projected Collateral Prepayments	11.40%		31.90%
Fair Value Inputs Losses	4.50%		2.60%
Fair Value Inputs Projected Collateral Recoveries	1.50%		2.30%
Fair Value Inputs Projected Collateral Scheduled Amortization	29.80%		33.30%
Income Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	50.30%		20.60%
Projected Collateral Prepayments	55.20%		52.30%
Fair Value Inputs Losses	28.30%		17.30%
Fair Value Inputs Projected Collateral Recoveries	27.20%		15.50%
Fair Value Inputs Projected Collateral Scheduled Amortization	51.50%		51.50%
Income Approach Valuation Technique [Member] | Collateralized Loan Obligations [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	20.50%		13.50%
Projected Collateral Prepayments	45.50%		41.10%
Fair Value Inputs Losses	10.70%		12.90%
Fair Value Inputs Projected Collateral Recoveries	8.60%		10.10%
Fair Value Inputs Projected Collateral Scheduled Amortization	35.20%		35.90%
Total Outstanding Collateral	100.00%		100.00%
Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 15,985,000		$ 13,780,000
Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	8.80%		19.20%
Fair Value Inputs Losses	0.10%		0.70%
Fair Value Inputs Projected Collateral Recoveries	0.90%		1.50%
Fair Value Inputs Projected Collateral Scheduled Amortization	77.80%		83.40%
Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	57.00%		25.00%
Fair Value Inputs Losses	5.30%		2.30%
Fair Value Inputs Projected Collateral Recoveries	20.50%		14.30%
Fair Value Inputs Projected Collateral Scheduled Amortization	99.00%		97.60%
Income Approach Valuation Technique [Member] | Private Label Commercial Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	23.60%		22.10%
Fair Value Inputs Losses	2.20%		1.60%
Fair Value Inputs Projected Collateral Recoveries	10.70%		8.40%
Fair Value Inputs Projected Collateral Scheduled Amortization	87.10%		90.00%
Total Outstanding Collateral	100.00%		100.00%
Income Approach Valuation Technique [Member] | Agency Interest Only Residential Mortgage-Backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 6,300,000		$ 3,851,000
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	0.00%		18.00%
Fair Value Inputs Losses	0.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	0.00%		0.00%
LIBOR OAS	1.42%	[1]	4.41%	[2]
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	100.00%		100.00%
Fair Value Inputs Losses	15.70%
Fair Value Inputs Projected Collateral Scheduled Amortization	88.10%		82.00%
LIBOR OAS	28.31%	[1]	16.72%	[2]
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	62.60%		70.40%
Fair Value Inputs Losses	1.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	36.40%		29.60%
Total Outstanding Collateral	100.00%		100.00%
LIBOR OAS	5.68%	[1]	6.22%	[2]
Income Approach Valuation Technique [Member] | Corporate debt and warrants [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 10,080,000		$ 13,920,000
Income Approach Valuation Technique [Member] | Corporate debt and warrants [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	19.70%		15.00%
Income Approach Valuation Technique [Member] | Corporate debt and warrants [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	19.70%		20.00%
Income Approach Valuation Technique [Member] | Corporate debt and warrants [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	19.70%		16.20%
Income Approach Valuation Technique [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 114,472,000		$ 115,376,000
Income Approach Valuation Technique [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	8.50%		9.00%
Projected Collateral Prepayments	0.00%		0.00%
Fair Value Inputs Losses	3.30%		1.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	0.00%		57.30%
Income Approach Valuation Technique [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	25.00%		15.00%
Projected Collateral Prepayments	45.40%		40.90%
Fair Value Inputs Losses	97.40%		33.80%
Fair Value Inputs Projected Collateral Scheduled Amortization	87.70%		80.80%
Income Approach Valuation Technique [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	10.90%		10.40%
Projected Collateral Prepayments	25.60%		30.90%
Fair Value Inputs Losses	9.90%		7.30%
Fair Value Inputs Projected Collateral Scheduled Amortization	64.50%		61.80%
Total Outstanding Collateral	100.00%		100.00%
Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 32,557,000		$ 43,847,000
Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	8.00%		9.80%
Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	17.20%		17.60%
Income Approach Valuation Technique [Member] | Performing Commercial Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	11.60%		11.90%
Income Approach Valuation Technique [Member] | Performing Residential Mortgage Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 78,576,000		$ 13,848,000
Income Approach Valuation Technique [Member] | Performing Residential Mortgage Loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	5.00%		5.50%
Income Approach Valuation Technique [Member] | Performing Residential Mortgage Loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	13.50%		8.00%
Income Approach Valuation Technique [Member] | Performing Residential Mortgage Loans [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	6.60%		6.50%
Income Approach Valuation Technique [Member] | Non-performing Residential Mortgage Loans and Residential Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 7,413,000		$ 12,331,000
Income Approach Valuation Technique [Member] | Non-performing Residential Mortgage Loans and Residential Real Estate Owned [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	5.80%		5.70%
Months to Resolution	1 month 24 days		3 months 12 days
Income Approach Valuation Technique [Member] | Non-performing Residential Mortgage Loans and Residential Real Estate Owned [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	39.90%		7.90%
Months to Resolution	162 months 27 days		113 months 18 days
Income Approach Valuation Technique [Member] | Non-performing Residential Mortgage Loans and Residential Real Estate Owned [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	9.70%		7.30%
Months to Resolution	41 months 27 days		20 months 18 days
Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans and Commercial Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 30,222,000		$ 30,984,000
Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans and Commercial Real Estate Owned [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	10.20%		10.20%
Months to Resolution	3 months		4 months
Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans and Commercial Real Estate Owned [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	27.80%		19.40%
Months to Resolution	39 months 3 days		24 months
Income Approach Valuation Technique [Member] | Non-performing Commercial Mortgage Loans and Commercial Real Estate Owned [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	16.30%		13.70%
Months to Resolution	19 months 15 days		9 months 10 days
Credit Default Swaps On Asset Backed Securities [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 5,070,000		$ 6,111,000
Credit Default Swaps On Asset Backed Securities [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	19.30%		26.60%
Fair Value Inputs Losses	15.30%		15.00%
Fair Value Inputs Projected Collateral Recoveries	4.70%		6.80%
Fair Value Inputs Projected Collateral Scheduled Amortization	43.20%		24.50%
Credit Default Swaps On Asset Backed Securities [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	29.80%		44.10%
Fair Value Inputs Losses	27.60%		33.70%
Fair Value Inputs Projected Collateral Recoveries	15.30%		16.90%
Fair Value Inputs Projected Collateral Scheduled Amortization	50.20%		33.10%
Credit Default Swaps On Asset Backed Securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Projected Collateral Prepayments	22.70%		32.60%
Fair Value Inputs Losses	22.20%		26.50%
Fair Value Inputs Projected Collateral Recoveries	8.70%		12.00%
Fair Value Inputs Projected Collateral Scheduled Amortization	46.40%		28.90%
Total Outstanding Collateral	100.00%		100.00%
Total Return Swaps [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ (94,000)		$ (4,577,000)
Total Return Swaps [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	98.25	[3]	36.38	[4]
Total Return Swaps [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	99.50	[3]	99.88	[4]
Total Return Swaps [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Non Binding Third-Party Valuation	98.77	[3]	56.38	[4]
Guarantees [Member] | Cash Flows [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure			$ (828,000)
Private Corporate Equity Investments [Member] | Non-exchange traded equity investments in commercial mortgage-related private partnerships [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 3,090,000		$ 10,558,000
Private Corporate Equity Investments [Member] | Non-exchange traded equity investments in commercial mortgage-related private partnerships [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	16.50%		14.00%
Fair Value Assumptions, Expected Term	2 months 27 days		14 months 9 days
Private Corporate Equity Investments [Member] | Non-exchange traded equity investments in commercial mortgage-related private partnerships [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	16.50%		16.50%
Fair Value Assumptions, Expected Term	2 months 27 days		27 months
Private Corporate Equity Investments [Member] | Non-exchange traded equity investments in commercial mortgage-related private partnerships [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	16.50%		14.70%
Fair Value Assumptions, Expected Term	2 months 27 days		23 months 15 days
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred and Common Equity Investment in Mortgage-Related Entities [Member] | Enterprise Value [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 2,500,000		$ 2,738,000
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred and Common Equity Investment in Mortgage-Related Entities [Member] | Enterprise Value [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Equity Multiple	1.3	[5]	2.7	[6]
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred and Common Equity Investment in Mortgage-Related Entities [Member] | Enterprise Value [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Equity Multiple	1.3	[5]	2.7	[6]
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred and Common Equity Investment in Mortgage-Related Entities [Member] | Enterprise Value [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Equity Multiple	1.3	[5]	2.7	[6]
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred and Common Equity Investment in Mortgage-Related Entities [Member] | Recent Transactions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value			$ 2,630,000
Private Corporate Equity Investments [Member] | Non-Exchange Traded Preferred Equity Investment in Mortgage-Related Entities [Member] | Recent Transactions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 12,500,000

[1] Shown in basis points.

[2] Shown in basis points.

[3] Represents valuations on underlying assets.

[4] Represents valuations on underlying assets.

[5] Represent an estimation of where market participants might value an enterprise.

[6] Represent an estimation of where market participants might value an enterprise.