v3.8.0.1
Valuation (Schedule Of Financial Instruments) (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- [1] $ 29,896 $ 35,595
Fair value repurchase agreements [1] 193,070 184,819
Investments sold short, at fair value- (675,650) (584,896)
Financial derivatives–liabilities, at fair value- [1] (32,278) (18,687)
Fair Value, Measurements, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments and financial derivatives–assets, at fair value and repurchase agreements 1,979,398 1,725,440
Total investments sold short and financial derivatives–liabilities, at fair value (707,928) (603,583)
Fair Value, Measurements, Recurring [Member] | Investments Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (675,650) (584,896)
Fair Value, Measurements, Recurring [Member] | Investments Sold Short [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (470,487) (404,728)
Fair Value, Measurements, Recurring [Member] | Investments Sold Short [Member] | Government debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (120,407) (132,442)
Fair Value, Measurements, Recurring [Member] | Investments Sold Short [Member] | Corporate Debt Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (70,567) (39,572)
Fair Value, Measurements, Recurring [Member] | Investments Sold Short [Member] | Common Stock Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (14,189) (8,154)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (32,278) (18,687)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (207) (256)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (11,646) (2,840)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (13,611) (6,654)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (1,495) (2,899)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (5,303) (5,162)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (304)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (69)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (16) (472)
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Liabilities [Member] | Mortgage Loan Purchase Commitments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (31)
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash Equivalents 60,000 90,000
Fair Value, Measurements, Recurring [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 1,756,432 1,505,026
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 937,210 897,967
Fair Value, Measurements, Recurring [Member] | Investments [Member] | US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 1,519 5,419
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Private Label Residential Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 152,201 143,608
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Private Label Commercial Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 30,053 43,268
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Commercial Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 67,895 61,129
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Residential Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 162,963 84,290
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Collateralized Loan Obligations [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 135,064 44,956
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 116,340 107,157 [2]
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Corporate Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 89,308 80,095
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Real Estate Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 25,762 3,349
Fair Value, Measurements, Recurring [Member] | Investments [Member] | Corporate Equity Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 38,117 33,788 [2]
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 29,896 35,595
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 4,530 5,326
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 631 2,744
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 10,109 2,360
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 6,987 16,713
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 6,721 8,102
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   155
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 52 44
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 143 29
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 723 16
Fair Value, Measurements, Recurring [Member] | Financial Derivatives - Assets [Member] | Warrant [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   106
Fair Value, Measurements, Recurring [Member] | Repurchase Agreements [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value repurchase agreements 193,070 184,819
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments and financial derivatives–assets, at fair value and repurchase agreements 983 4,467
Total investments sold short and financial derivatives–liabilities, at fair value (14,189) (8,223)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (14,189) (8,154)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments Sold Short [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments Sold Short [Member] | Government debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments Sold Short [Member] | Corporate Debt Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments Sold Short [Member] | Common Stock Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (14,189) (8,154)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 (69)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (69)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Liabilities [Member] | Mortgage Loan Purchase Commitments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash Equivalents [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash Equivalents 60,000 90,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 790 4,396
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Private Label Residential Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Private Label Commercial Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Commercial Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Residential Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Collateralized Loan Obligations [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0 [2]
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Corporate Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Real Estate Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Investments [Member] | Corporate Equity Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 790 4,396 [2]
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 193 71
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 50 42
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 143 29
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial Derivatives - Assets [Member] | Warrant [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Repurchase Agreements [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value repurchase agreements 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments and financial derivatives–assets, at fair value and repurchase agreements 1,432,673 1,197,136
Total investments sold short and financial derivatives–liabilities, at fair value (693,532) (594,855)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (661,461) (576,742)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments Sold Short [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (470,487) (404,728)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments Sold Short [Member] | Government debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (120,407) (132,442)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments Sold Short [Member] | Corporate Debt Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- (70,567) (39,572)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments Sold Short [Member] | Common Stock Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (32,071) (18,113)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (11,646) (2,840)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (13,611) (6,654)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (1,495) (2,899)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (5,303) (5,162)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (55)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (16) (472)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Liabilities [Member] | Mortgage Loan Purchase Commitments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (31)
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Cash Equivalents [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash Equivalents 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 1,214,430 982,380
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 931,391 868,345
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 1,519 5,419
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Private Label Residential Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 78,553 53,525
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Private Label Commercial Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 18,421 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Commercial Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Residential Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Collateralized Loan Obligations [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 108,146 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0 [2]
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Corporate Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 76,400 55,091
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Real Estate Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Investments [Member] | Corporate Equity Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0 [2]
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 25,173 29,937
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 631 2,744
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 10,109 2,360
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 6,987 16,713
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 6,721 8,102
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 2 2
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 723 16
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial Derivatives - Assets [Member] | Warrant [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Repurchase Agreements [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value repurchase agreements 193,070 184,819
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total investments and financial derivatives–assets, at fair value and repurchase agreements 545,742 523,837
Total investments sold short and financial derivatives–liabilities, at fair value (207) (505)
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments Sold Short [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments Sold Short [Member] | Government debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments Sold Short [Member] | Corporate Debt Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments Sold Short [Member] | Common Stock Sold Short [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments sold short, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (207) (505)
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- (207) (256)
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   (249)
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Liabilities [Member] | Mortgage Loan Purchase Commitments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–liabilities, at fair value-   0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Cash Equivalents [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash Equivalents 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 541,212 518,250
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Agency residential mortgage-backed securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 5,819 29,622
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | US Treasury Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Private Label Residential Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 73,648 90,083
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Private Label Commercial Mortgage-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 11,632 43,268
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Commercial Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 67,895 61,129
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Residential Mortgage Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 162,963 84,290
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Collateralized Loan Obligations [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 26,918 44,956
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Consumer loans and asset-backed securities backed by consumer loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 116,340 107,157 [2]
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Corporate Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 12,908 25,004
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Real Estate Owned [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 25,762 3,349
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Investments [Member] | Corporate Equity Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, at fair value- 37,327 29,392 [2]
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 4,530 5,587
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 4,530 5,326
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bond Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Corporate Bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Credit Default Swaps On Asset Backed Indices [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Interest Rate Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Total Return Swaps [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   155
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Options [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Futures [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Forwards [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value- 0 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial Derivatives - Assets [Member] | Warrant [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial derivatives–assets, at fair value-   106
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Repurchase Agreements [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value repurchase agreements $ 0 $ 0
[1] In the Company's Consolidated Statement of Assets, Liabilities, and Equity, all balances associated with repurchase agreements, reverse repurchase agreements, and financial derivatives are presented on a gross basis.
[2] Conformed to current period presentation.