Fair Value Disclosures (Quantitative Information About Significant Unobservable Inputs Used In Level 3 Fair Value Measurements) (Details) (USD $)	12 Months Ended
	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	$ 8,398,000
Equity Options [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Option model
Significant Unobservable Input(s)	Volatility
Fair value assumptions expected volatility inputs, weighted average	39.00%
Equity Options [Member] | Minimum [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value assumptions expected volatility inputs	36.25%
Equity Options [Member] | Maximum [Member] | Derivatives, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value assumptions expected volatility inputs	41.00%
Loans [Member] | Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	8,106,000
Valuation Technique	Comparable pricing
Significant Unobservable Input(s)	Comparable bond or loan price
Fair Value Inputs, Comparable bond or loan price	101.88
Corporate Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	8,034,000
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] | Non-exchange traded securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Market approach
Significant Unobservable Input(s)	EBITDA (a) multiple	[1]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple, Weighted Average	4.53
Corporate Equity Securities [Member] | Warrants [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Option model
Significant Unobservable Input(s)	Volatility
Fair value assumptions expected volatility inputs	36.00%
Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	17,699,000
Corporate Debt Securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Scenario analysis
Significant Unobservable Input(s)	Estimated recovery percentage
Fair value assumptions estimated recovery percentage inputs	24.00%
Corporate Debt Securities [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Comparable pricing
Significant Unobservable Input(s)	Comparable bond or loan price
Fair Value Inputs, Comparable bond or loan price, weighted average	69.91
Corporate Debt Securities [Member] | Range Three [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Market approach
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield	13.00%
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
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
Collateralized Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	34,316,000
Valuation Technique	Discounted cash flows
Collateralized Debt Obligations [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant prepayment rate
Fair Value Inputs, Constant prepayment rate, weighted average	13.00%
Collateralized Debt Obligations [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant default rate
Fair Value Inputs, Constant default rate, weighted average	2.00%
Collateralized Debt Obligations [Member] | Range Three [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Loss severity
Fair Value Inputs, Loss severity, weighted average	38.00%
Collateralized Debt Obligations [Member] | Range Four [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield, weighted average	28.00%
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	0.00%
Fair Value Inputs, Constant default rate	2.00%
Fair Value Inputs, Loss severity	30.00%
Fair Value Inputs, Yield	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%
Fair Value Inputs, Constant default rate	3.00%
Fair Value Inputs, Loss severity	85.00%
Fair Value Inputs, Yield	91.00%
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	105,492,000
Valuation Technique	Discounted cash flows
Residential Mortgage-Backed Securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant prepayment rate
Fair Value Inputs, Constant prepayment rate, weighted average	11.00%
Residential Mortgage-Backed Securities [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant default rate
Fair Value Inputs, Constant default rate, weighted average	17.00%
Residential Mortgage-Backed Securities [Member] | Range Three [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Loss severity
Fair Value Inputs, Loss severity, weighted average	48.00%
Residential Mortgage-Backed Securities [Member] | Range Four [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield, weighted average	7.00%
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	2.00%
Fair Value Inputs, Constant default rate	1.00%
Fair Value Inputs, Loss severity	30.00%
Fair Value Inputs, Yield	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%
Fair Value Inputs, Constant default rate	100.00%
Fair Value Inputs, Loss severity	90.00%
Fair Value Inputs, Yield	20.00%
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	17,568,000
Valuation Technique	Discounted cash flows
Commercial Mortgage-Backed Securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield, weighted average	14.00%
Commercial Mortgage-Backed Securities [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Cumulative loss rate
Fair Value Inputs, Cumulative loss rate, weighted average	11.00%
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	12.00%
Fair Value Inputs, Cumulative loss rate	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	20.00%
Fair Value Inputs, Cumulative loss rate	28.20%
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	101,931,000
Loans And Other Receivables [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Comparable pricing
Significant Unobservable Input(s)	Comparable bond or loan price
Fair Value Inputs, Comparable bond or loan price, weighted average	98.90
Loans And Other Receivables [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Market approach
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield, weighted average	10.00%
Loans And Other Receivables [Member] | Range Three [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	EBITDA (a) multiple	[1]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	6.9
Loans And Other Receivables [Member] | Range Four [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Scenario analysis
Significant Unobservable Input(s)	Estimated recovery percentage
Fair value assumptions estimated recovery percentage, weighted average	74.00%
Loans And Other Receivables [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value assumptions estimated recovery percentage inputs	16.90%
Fair Value Inputs, Yield	8.75%
Fair Value Inputs, Comparable bond or loan price	91.00
Loans And Other Receivables [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value assumptions estimated recovery percentage inputs	92.00%
Fair Value Inputs, Yield	13.50%
Fair Value Inputs, Comparable bond or loan price	101.00
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	12,611,000
Valuation Technique	Discounted cash flows
Other Asset-Backed Securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant prepayment rate
Fair Value Inputs, Constant prepayment rate, weighted average	17.00%
Other Asset-Backed Securities [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Constant default rate
Fair Value Inputs, Constant default rate, weighted average	7.00%
Other Asset-Backed Securities [Member] | Range Three [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Loss severity
Fair Value Inputs, Loss severity, weighted average	64.00%
Other Asset-Backed Securities [Member] | Range Four [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s)	Yield
Fair Value Inputs, Yield, weighted average	18.00%
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%
Derivatives, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value of Financial Instruments Owned	1,493,000
Derivatives, Assets [Member] | Loan commitments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Comparable pricing
Significant Unobservable Input(s)	Comparable bond or loan price
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	$ 30,203,000
Investments At Fair Value [Member] | Private equity securities [Member] | Range One [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Comparable pricing
Significant Unobservable Input(s)	Comparable share price
Fair Value Inputs, Comparable share price	$ 414.00
Investments At Fair Value [Member] | Private equity securities [Member] | Range Two [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Valuation Technique	Market approach
Significant Unobservable Input(s)	Discount rate
Fair Value Inputs, Discount rate, weighted average	23.00%
Investments At Fair Value [Member] | Private equity securities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount rate	15.00%
Investments At Fair Value [Member] | Private equity securities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount rate	30.00%

[1] Earnings before interest, taxes, depreciation and amortization ("EBITDA").