Valuation (Schedule of Significant Unobservable Inputs, Qualitative Information) (Details) - Level 3	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($)
Non-Agency RMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 127,838,000	$ 89,581,000
Fair Value of Level 3 Assets, Negative Yield	$ 300,000	$ 600,000
Non-Agency RMBS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair Value Inputs, Yield Including Negative	7.30%	8.00%
Non-Agency RMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.007	0.005
Non-Agency RMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.526	0.651
Non-Agency RMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.074	0.081
Non-Agency RMBS | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0	0.008
Non-Agency RMBS | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.991	0.765
Non-Agency RMBS | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.453	0.531
Non-Agency RMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.004	0.001
Non-Agency RMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.726	0.489
Non-Agency RMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.184	0.177
Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0	0
Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.791	0.324
Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.168	0.065
CMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 63,148,000	$ 29,805,000
CMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.037	0.037
CMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.263	0.157
CMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.087	0.076
CMBS | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0	0
CMBS | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0	1.000
CMBS | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0	0.006
CMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.007	0
CMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.107	0.030
CMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.036	0.002
CMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.724	0
CMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.961	0.106
CMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.906	0.020
Agency RMBS | Interest only securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 11,663,000	$ 19,904,000
Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.083	0.123
Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	1.000	1.000
Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.759	0.705
Corporate equity securities | Non-exchange traded preferred equity investment in loan origination entity
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 3,000,000
CLOs
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 111,100,000	$ 44,979,000
CLOs | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.034	0.032
CLOs | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.354	0.419
CLOs | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.105	0.140
CLOs | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.412	0.485
CLOs | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.977	0.883
CLOs | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.657	0.832
CLOs | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.017	0.047
CLOs | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.289	0.364
CLOs | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.112	0.088
CLOs | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.006	0.037
CLOs | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.152	0.151
CLOs | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.079	0.057
Asset-backed securities, backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 44,925,000	$ 48,610,000
Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.126	0.038
Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.275	0.342
Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.156	0.127
Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.000	0.000
Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.116	0.112
Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.077	0.097
Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.010	0.006
Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.211	0.180
Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.171	0.154
Corporate loan [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value		$ 18,510,000
Corporate loan [Member] | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input		0.150
Corporate loan [Member] | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input		0.210
Corporate loan [Member] | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input		0.178
Total return swaps | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.220	0.085
Derivative Liability, Measurement Input	0.168	0.277
Total return swaps | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.220	0.277
Derivative Liability, Measurement Input	0.168	0.277
Total return swaps | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.220	0.115
Derivative Liability, Measurement Input	0.168	0.277
Valuation, Market Approach | Non-Agency RMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 70,619,000	$ 38,754,000	$ 36,945,000
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			17.42
Securities, measurement input | $ / shares	9.53	6.68
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			178.00
Securities, measurement input | $ / shares	204.61	144.79
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			78.31
Securities, measurement input | $ / shares	85.70	86.21
Valuation, Market Approach | CMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 53,199,000	$ 29,630,000	$ 576,000
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			5.93
Securities, measurement input | $ / shares	4.79	5.08
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			6.36
Securities, measurement input | $ / shares	98.00	80.72
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			6.14
Securities, measurement input | $ / shares	65.20	64.73
Valuation, Market Approach | Agency RMBS | Interest only securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 4,844,000	$ 3,753,000	$ 744,000
Valuation, Market Approach | Agency RMBS | Interest only securities | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			1.70
Securities, measurement input | $ / shares	1.91	1.36
Valuation, Market Approach | Agency RMBS | Interest only securities | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			9.12
Securities, measurement input | $ / shares	18.91	16.61
Valuation, Market Approach | Agency RMBS | Interest only securities | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			5.64
Securities, measurement input | $ / shares	8.38	5.11
Valuation, Market Approach | CLOs
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 102,910,000	$ 38,220,000	$ 5,828,000
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			2.64
Securities, measurement input | $ / shares	2.00	40.00
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			375.00
Securities, measurement input | $ / shares	330.00	96.00
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			167.78
Securities, measurement input | $ / shares	88.66	73.98
Valuation, Market Approach | Corporate debt, non-exchange traded corporate equity, and secured notes [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 13,976,000
Valuation, Market Approach | Corporate debt, non-exchange traded corporate equity, and secured notes [Member] | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			9.69
Valuation, Market Approach | Corporate debt, non-exchange traded corporate equity, and secured notes [Member] | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			91.00
Valuation, Market Approach | Corporate debt, non-exchange traded corporate equity, and secured notes [Member] | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			59.18
Valuation, Market Approach | Asset-backed securities, backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 97,000	$ 139,000
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	96.51	95.47
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	98.43	96.78
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	97.33	96.12
Valuation, Market Approach | Corporate loan [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 5,855,000	$ 6,010,000
Valuation, Market Approach | Corporate loan [Member] | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	100.00	100.00
Valuation, Market Approach | Corporate loan [Member] | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	100.00	100.00
Valuation, Market Approach | Corporate loan [Member] | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	100.00	100.00
Valuation, Market Approach | Other secured borrowings, at fair value
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ (754,921,000)	$ (594,396,000)
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	85.37	97.77
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	105.61	100.45
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	102.04	100.61
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0.016	0.029
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0.030	0.040
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0.026	0.033
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0	0
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0.753	0.966
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt instrument, measurement input	0.487	0.572
Valuation, Income Approach | Non-Agency RMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 57,219,000	$ 50,827,000	$ 54,346,000
Valuation, Income Approach | Non-Agency RMBS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral			100.00%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.50%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			66.10%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			10.70%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			16.00%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			92.10%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			50.40%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			0.00%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			23.10%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			8.70%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			1.50%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			14.60%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			7.30%
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.10%
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			61.80%
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			33.60%
Valuation, Income Approach | CMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	9,949,000	175,000	$ 227,000
Valuation, Income Approach | CMBS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral			100.00%
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.40%
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.40%
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.40%
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.00%
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.00%
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.00%
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.60%
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.60%
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.60%
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			91.40%
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			91.40%
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			91.40%
Valuation, Income Approach | Agency RMBS | Interest only securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	6,819,000	16,151,000	$ 6,549,000
Fair Value of Agency IOs, negative OAS measurement input	$ 4,500,000	$ 300,000
Valuation, Income Approach | Agency RMBS | Interest only securities | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.11%
Valuation, Income Approach | Agency RMBS | Interest only securities | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			35.21%
Valuation, Income Approach | Agency RMBS | Interest only securities | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.77%
Total outstanding collateral			100.00%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, LIBOR OAS | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0297	0.0093
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, LIBOR OAS | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.2886	0.3527
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, LIBOR OAS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0914	0.0583
Valuation, Income Approach | Agency RMBS | Interest only securities | Net LIBOR OAS [Member] | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0396	0.0576
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			37.70%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			100.00%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			66.20%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			0.00%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			62.30%
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			33.80%
Valuation, Income Approach | Corporate Debt and non-exchange traded corporate equity [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 4,793,000
Valuation, Income Approach | Corporate Debt and non-exchange traded corporate equity [Member] | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			17.50%
Valuation, Income Approach | Corporate Debt and non-exchange traded corporate equity [Member] | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			17.50%
Valuation, Income Approach | Corporate Debt and non-exchange traded corporate equity [Member] | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			17.50%
Valuation, Income Approach | Corporate debt and equity
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 5,672,000	$ 2,507,000
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.081	0.072
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.108	0.100
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.097	0.088
Valuation, Income Approach | CLOs
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 8,190,000	$ 6,759,000	$ 9,087,000
Valuation, Income Approach | CLOs | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral			100.00%
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			12.60%
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			103.10%
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			26.70%
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			8.10%
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			88.40%
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			65.20%
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.70%
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			40.80%
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			13.50%
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			4.20%
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			38.00%
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			11.90%
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			3.50%
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			13.50%
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			9.40%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 206,761,000
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral			100.00%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			7.00%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			18.30%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			8.50%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			0.00%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			45.90%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			33.50%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.60%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			84.80%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			9.10%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			15.20%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			96.60%
Valuation, Income Approach | Consumer loans and asset-backed securities backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			57.40%
Valuation, Income Approach | Asset-backed securities, backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	44,828,000	48,471,000
Valuation, Income Approach | Consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 47,525,000	$ 186,954,000
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.078	0.067
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.281	0.196
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.112	0.094
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.000	0.000
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.360	0.442
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.173	0.160
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.009	0.037
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.866	0.845
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.094	0.086
Valuation, Income Approach | Corporate loan [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value		$ 12,500,000
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.211
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.211
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.211
Valuation, Income Approach | Performing commercial mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 163,876,000
Valuation, Income Approach | Performing commercial mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			8.00%
Valuation, Income Approach | Performing commercial mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			22.50%
Valuation, Income Approach | Performing commercial mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			9.60%
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 80,513,000
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			3 months
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			16 months
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			7 months 27 days
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			9.60%
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			27.40%
Valuation, Income Approach | Non-performing commercial mortgage loans and commercial real estate owned | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			13.20%
Valuation, Income Approach | Performing residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 171,367,000
Valuation, Income Approach | Performing residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			2.70%
Valuation, Income Approach | Performing residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			12.90%
Valuation, Income Approach | Performing residential mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			6.00%
Valuation, Income Approach | Securitized residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 314,202,000
Valuation, Income Approach | Securitized residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			4.30%
Valuation, Income Approach | Securitized residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			4.60%
Valuation, Income Approach | Securitized residential mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			4.60%
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 12,557,000
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			1 month 27 days
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			42 months 6 days
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time			27 months 24 days
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			4.30%
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			25.10%
Valuation, Income Approach | Non-performing residential mortgage loans and residential real estate owned | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			11.30%
Valuation, Income Approach | Credit default swaps on asset-backed securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 347,000	$ 993,000	$ 1,472,000
Valuation, Income Approach | Credit default swaps on asset-backed securities | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral			100.00%
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			33.60%
Derivative asset, measurement input	0.327	0.354
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			42.00%
Derivative asset, measurement input	0.397	0.420
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			36.50%
Derivative asset, measurement input	0.381	0.373
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			11.10%
Derivative asset, measurement input	0.066	0.042
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			15.60%
Derivative asset, measurement input	0.108	0.124
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			12.80%
Derivative asset, measurement input	0.089	0.102
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			10.30%
Derivative asset, measurement input	0.139	0.100
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			18.70%
Derivative asset, measurement input	0.181	0.182
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			15.80%
Derivative asset, measurement input	0.156	0.153
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			32.00%
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			36.50%
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			34.90%
Valuation, Income Approach | Total return swaps
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 9,000	$ 620,000
Fair value	(484,000)	(436,000)
Valuation, Income Approach | Investment in unconsolidated entities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 5,192,000
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			12.90%
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			16.10%
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, percent			15.40%
Valuation, Income Approach | Other secured borrowings, at fair value
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ (297,948,000)
Valuation, Income Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt, measurement input			3.90%
Valuation, Income Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt, measurement input			4.40%
Valuation, Income Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Debt, measurement input			4.30%
Enterprise Value | Investment in unconsolidated entities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 141,620,000	$ 71,850,000
Enterprise Value | Corporate equity securities | Non-exchange traded common equity investment in mortgage-related entity
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 6,750,000
Enterprise Value | Corporate equity securities | Non-exchange traded common equity investment in mortgage-related entity | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			3.3
Enterprise Value | Corporate equity securities | Non-exchange traded common equity investment in mortgage-related entity | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			3.3
Enterprise Value | Corporate equity securities | Non-exchange traded common equity investment in mortgage-related entity | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			3.3
Enterprise Value | Corporate equity securities | Non-exchange traded preferred equity investment in mortgage-related entity
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value			$ 27,317,000
Enterprise Value | Corporate equity securities | Non-exchange traded preferred equity investment in mortgage-related entity | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			1.1
Enterprise Value | Corporate equity securities | Non-exchange traded preferred equity investment in mortgage-related entity | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			1.1
Enterprise Value | Corporate equity securities | Non-exchange traded preferred equity investment in mortgage-related entity | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input			1.1
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input	1.0	1.0
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input	6.2	4.7
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input	1.4	1.4
Performing and/or Re-performing | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 353,924,000
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.025	0.004
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.285	0.195
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.054	0.063
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Offered Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	60.00
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Offered Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	103.88
Performing and/or Re-performing | Residential mortgage loans | Measurement Input, Offered Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	103.44
Performing and/or Re-performing | Valuation, Market Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 15,659,000
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 181,545,000	$ 248,214,000
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.037	0.077
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.097	0.166
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.081	0.088
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 338,265,000	$ 289,672,000
Securitized loans [Member] | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	801,343,000	628,415,000
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 783,162,000	$ 621,762,000
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	5.34	2.56
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	105.61	100.45
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	100.22	98.23
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 18,182,000	$ 6,653,000
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0	0.032
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.387	0.043
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.044	0.036
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 26,400,000	$ 1,500,000
Non-performing | Residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.012	0.010
Non-performing | Residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.410	0.266
Non-performing | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.121	0.092
Non-performing | Residential mortgage loans | Measurement Input recovery amount | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	$ 0.009	$ 0.280
Non-performing | Residential mortgage loans | Measurement Input recovery amount | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	17.130	4.643
Non-performing | Residential mortgage loans | Measurement Input recovery amount | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	0.306	0.943
Non-performing | Valuation, Income Approach | Commercial mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 31,486,000	$ 26,545,000
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	1 month 24 days	1 month 3 days
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	5 months 24 days	23 months
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	3 months 21 days	11 months 12 days
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.086	0.098
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.146	0.147
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.108	0.124
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	$ 1.000	$ 1.000
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	1.024	1.000
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input, Recovery Amount	1.008	1.000
Non-performing | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 31,802,000	$ 14,116,000
Non-performing | Valuation, Income Approach | Residential mortgage loans | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	0 months	1 month 3 days
Non-performing | Valuation, Income Approach | Residential mortgage loans | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	106 months 18 days	165 months 12 days
Non-performing | Valuation, Income Approach | Residential mortgage loans | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	30 months	54 months 18 days