Fair Value Disclosures (Quantitative Information About Significant Unobservable Inputs Used In Level 3 Fair Value Measurements) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Trading Liabilities	$ 14,784	$ 8,398
Fair Value Inputs, Yield	4.582%
Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Trading Liabilities		8,106
Fair Value Inputs, Comparable bond or loan price		$ 101.880
Minimum [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Volatility		36.25%
Fair Value Inputs, Comparable loan price	$ 93.50
Maximum [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Volatility		41.00%
Fair Value Inputs, Comparable loan price	$ 99.625
Weighted Average [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Volatility		39.00%
Fair Value Inputs, Comparable loan price	$ 94.64
Corporate Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	7,777	8,034
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	3.05
Fair Value Inputs, Volatility		36.00%
Fair Value Inputs, Transaction Level	$ 2.95
Corporate Equity Securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple		4.0
Corporate Equity Securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple		5.5
Corporate Equity Securities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple		4.53
Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	34,965	17,699
Fair Value Inputs, Estimated recovery percentage		24.00%
Fair Value Inputs, Constant prepayment rate	20.00%
Fair Value Inputs, Constant default rate	2.00%
Fair Value Inputs, Loss severity	25.00%
Fair Value Inputs, Yield	16.00%	13.00%
Fair Value Inputs, Discount rate/yield	31.90%
Corporate Debt Securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Comparable bond or loan price		69.10
Fair Value Inputs, Yield	3.70%
Corporate Debt Securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Comparable bond or loan price		70.50
Fair Value Inputs, Yield	4.40%
Corporate Debt Securities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Comparable bond or loan price		69.91
Fair Value Inputs, Yield	4.20%
Collateralized Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	41,690	34,316
Fair Value Inputs, Constant default rate	2.00%
Collateralized Debt Obligations [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	10.00%	0.00%
Fair Value Inputs, Constant default rate		2.00%
Fair Value Inputs, Loss severity	25.00%	30.00%
Fair Value Inputs, Yield	0.00%	3.00%
Collateralized Debt Obligations [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	20.00%	20.00%
Fair Value Inputs, Constant default rate		3.00%
Fair Value Inputs, Loss severity	95.00%	85.00%
Fair Value Inputs, Yield	47.30%	91.00%
Collateralized Debt Obligations [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	15.29%	13.00%
Fair Value Inputs, Constant default rate		2.00%
Fair Value Inputs, Loss severity	55.70%	38.00%
Fair Value Inputs, Yield	7.83%	28.00%
U.S. Government And Federal Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	2,494
Fair Value Inputs, Transaction Level	$ 100.00
Residential Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	81,034	105,492
Residential Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	3.00%	2.00%
Fair Value Inputs, Constant default rate	1.00%	1.00%
Fair Value Inputs, Loss severity	20.00%	30.00%
Fair Value Inputs, Yield	1.20%	0.00%
Residential Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	50.00%	50.00%
Fair Value Inputs, Constant default rate	100.00%	100.00%
Fair Value Inputs, Loss severity	80.00%	90.00%
Fair Value Inputs, Yield	12.60%	20.00%
Residential Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate	11.90%	11.00%
Fair Value Inputs, Constant default rate	14.50%	17.00%
Fair Value Inputs, Loss severity	48.40%	48.00%
Fair Value Inputs, Yield	6.00%	7.00%
Commercial Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	19,327	17,568
Commercial Mortgage-Backed Securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Yield	7.60%	12.00%
Fair Value Inputs, Cumulative loss rate	4.60%	5.00%
Commercial Mortgage-Backed Securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Yield	15.00%	20.00%
Fair Value Inputs, Cumulative loss rate	74.00%	28.20%
Commercial Mortgage-Backed Securities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Yield	11.60%	14.00%
Fair Value Inputs, Cumulative loss rate	16.70%	11.00%
Other Asset-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	2,079	12,611
Fair Value Inputs, Constant prepayment rate	0.00%
Fair Value Inputs, Constant default rate	0.00%
Fair Value Inputs, Loss severity	0.00%
Fair Value Inputs, Yield	7.00%
Other Asset-Backed Securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate		4.00%
Fair Value Inputs, Constant default rate		2.00%
Fair Value Inputs, Loss severity		40.00%
Fair Value Inputs, Yield		3.00%
Other Asset-Backed Securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate		30.00%
Fair Value Inputs, Constant default rate		11.00%
Fair Value Inputs, Loss severity		92.00%
Fair Value Inputs, Yield		29.00%
Other Asset-Backed Securities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Constant prepayment rate		17.00%
Fair Value Inputs, Constant default rate		7.00%
Fair Value Inputs, Loss severity		64.00%
Fair Value Inputs, Yield		18.00%
Loans And Other Receivables [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	179,189	101,931
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple		6.9
Loans And Other Receivables [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	3.05
Fair Value Inputs, Estimated recovery percentage	10.33%	16.90%
Fair Value Inputs, Comparable bond or loan price	$ 92.5	$ 91
Fair Value Inputs, Yield	2.60%	8.75%
Loans And Other Receivables [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	7
Fair Value Inputs, Estimated recovery percentage	81.30%	92.00%
Fair Value Inputs, Comparable bond or loan price	$ 100.000	$ 101.000
Fair Value Inputs, Yield	4.60%	13.50%
Loans And Other Receivables [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	6.64
Fair Value Inputs, Estimated recovery percentage	70.90%	74.00%
Fair Value Inputs, Comparable bond or loan price	$ 99.63	$ 98.90
Fair Value Inputs, Yield	3.90%	10.00%
Derivatives, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned		1,493
Fair Value Inputs, Comparable bond or loan price		$ 100.875
Investments At Fair Value [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	$ 52,226	$ 30,203
Fair Value Inputs, Comparable share price	$ 26.8	$ 414.0
Fair Value Inputs, Transaction Level	$ 50.36
Investments At Fair Value [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount rate	15.00%	15.00%
Investments At Fair Value [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount rate	30.00%	30.00%
Investments At Fair Value [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount rate	23.00%	23.00%