Valuation (Schedule of Significant Unobservable Inputs, Qualitative Information) (Details) - Level 3 $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares
Total return swaps | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.106	0.085
Derivative Liability, Measurement Input	0.211	0.277
Total return swaps | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.106	0.277
Derivative Liability, Measurement Input	0.211	0.277
Total return swaps | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.106	0.115
Derivative Liability, Measurement Input	0.211	0.277
Valuation, Market Approach | Non-Agency RMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 92,090	$ 38,754
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	9.03	6.68
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	305.65	144.79
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	89.49	86.21
Valuation, Market Approach | CMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 54,282	$ 29,630
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	4.13	5.08
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	91.23	80.72
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	50.98	64.73
Valuation, Market Approach | Agency RMBS | Interest only securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 4,662	$ 3,753
Valuation, Market Approach | Agency RMBS | Interest only securities | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	0.68	1.36
Valuation, Market Approach | Agency RMBS | Interest only securities | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	15.24	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]
Securities, measurement input | $ / shares	1.75	5.11
Valuation, Market Approach | CLOs
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 121,931	$ 38,220
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	16.35	40.00
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	310.00	96.00
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input | $ / shares	81.85	73.98
Valuation, Market Approach | Asset-backed securities, backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 116	$ 139
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	95.27	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	96.83	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	96.24	96.12
Valuation, Market Approach | Corporate loan [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 6,227	$ 6,010
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, Income Approach | Non-Agency RMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 36,517	$ 50,827
Valuation, Income Approach | Non-Agency RMBS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	100.00%
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.002	0.033
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.570	0.609
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.113	0.100
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.004	0.008
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.793	0.720
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.564	0.493
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.000	0.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.247	0.227
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.055	0.066
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.000	0.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.271	0.324
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.105	0.069
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.147	0.169
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.876	0.929
Valuation, Income Approach | Non-Agency RMBS | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.276	0.372
Valuation, Income Approach | CMBS
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 11,413	$ 175
Valuation, Income Approach | CMBS | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	100.00%
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.108	0.100
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.318	0.100
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.120	0.100
Valuation, Income Approach | CMBS | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		1.000
Valuation, Income Approach | CMBS | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		1.000
Valuation, Income Approach | CMBS | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		1.000
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.001
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.017
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.013
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.011
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.053
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.037
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.930
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.988
Valuation, Income Approach | CMBS | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.950
Valuation, Income Approach | Agency RMBS | Interest only securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 8,245	$ 16,151
Fair Value of Agency IOs, negative OAS measurement input	$ 1,200
Valuation, Income Approach | Agency RMBS | Interest only securities | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	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	0.08	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	0.3992	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	0.0968	0.0701
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	0.2007
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.024	0.123
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.906	1.000
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.697	0.723
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.094	0.000
Valuation, Income Approach | Agency RMBS | Interest only securities | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.976	0.877
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]
Securities, measurement input	0.303	0.277
Valuation, Income Approach | Corporate debt and equity
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 3,035	$ 2,507
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.100	0.100
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.100	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	0.100	0.100
Valuation, Income Approach | Investment in unconsolidated entities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value		$ 30,458
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input		0.037
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input		0.148
Valuation, Income Approach | Investment in unconsolidated entities | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Equity method investment, measurement input		0.099
Valuation, Income Approach | CLOs
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 14,535	$ 6,759
Valuation, Income Approach | CLOs | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	100.00%
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.140	0.140
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.283	0.419
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.203	0.262
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.732	0.485
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.852	0.846
Valuation, Income Approach | CLOs | Measurement Input, Prepayment Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.815	0.725
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.081	0.117
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.138	0.364
Valuation, Income Approach | CLOs | Measurement Input, Default Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.096	0.199
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.063	0.037
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.108	0.151
Valuation, Income Approach | CLOs | Measurement Input, Projected Collateral Recoveries | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.073	0.076
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.000
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.026
Valuation, Income Approach | CLOs | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.016
Valuation, Income Approach | Asset-backed securities, backed by consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 47,825	$ 48,471
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	100.00%
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.140	0.120
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.217	0.202
Valuation, Income Approach | 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	0.141	0.121
Valuation, Income Approach | 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
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.093	0.112
Valuation, Income Approach | 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	0.073	0.097
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.009	0.006
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.195	0.180
Valuation, Income Approach | 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	0.155	0.154
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.717	0.713
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.991	0.994
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.772	0.749
Valuation, Income Approach | Consumer loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 166,681	$ 186,954
Valuation, Income Approach | Consumer loans | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Total outstanding collateral	100.00%	100.00%
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.090	0.070
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.120	0.100
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.100	0.081
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	0.396	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	0.132	0.160
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.018	0.030
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	0.100	0.086
Valuation, Income Approach | Consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.134	0.155
Valuation, Income Approach | Consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.982	0.958
Valuation, Income Approach | Consumer loans | Measurement input, Projected Collateral Scheduled Amortization | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.768	0.754
Valuation, Income Approach | Corporate loan [Member]
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value		$ 12,500
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		0.150
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		0.180
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Weighted Average
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Securities, measurement input		0.168
Valuation, Income Approach | Credit default swaps on asset-backed securities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 353	$ 993
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%	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]
Derivative asset, measurement input	0.344	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]
Derivative asset, measurement input	0.409	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]
Derivative asset, measurement input	0.394	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]
Derivative asset, measurement input	0.125	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]
Derivative asset, measurement input	0.130	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]
Derivative asset, measurement input	0.128	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]
Derivative asset, measurement input	0.086	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]
Derivative asset, measurement input	0.169	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]
Derivative asset, measurement input	0.120	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]
Derivative asset, measurement input	0.350	0.362
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]
Derivative asset, measurement input	0.388	0.415
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]
Derivative asset, measurement input	0.358	0.372
Valuation, Income Approach | Total return swaps
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 442	$ 620
Fair value	(77)	(436)
Valuation, Income Approach | Other secured borrowings, at fair value
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ (742,688)	$ (594,396)
Valuation, Income 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	0.025	0.029
Valuation, Income 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	0.034	0.040
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 instrument, measurement input	0.027	0.033
Enterprise Value | Investment in unconsolidated entities
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 72,553	$ 41,392
Enterprise Value | 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
Enterprise Value | 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	4.0	4.7
Enterprise Value | 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	1.3	1.7
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	0.035	0.016
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	0.568	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	0.078	0.062
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 271,608	$ 248,214
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	0.064	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	0.110	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	0.080	0.088
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 113,443	$ 289,672
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 806,114	$ 628,415
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	0.026	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	0.087	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	0.048	0.036
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 34,100	$ 1,500
Non-performing | Residential mortgage loans | Measurement Input, Discount Rate | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.037	0.010
Non-performing | Residential mortgage loans | Measurement Input, Discount Rate | Maximum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Loans, Measurement Input	0.284	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	0.099	0.091
Non-performing | Valuation, Income Approach | Commercial mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 23,888	$ 26,545
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	5 months 25 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	11 months 25 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	9 months	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	0.078	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	0.132	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	0.117	0.124
Non-performing | Valuation, Income Approach | Residential mortgage loans
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Fair value	$ 28,890	$ 14,116
Non-performing | Valuation, Income Approach | Residential mortgage loans | Minimum
Fair Value Measurements Inputs and Valuation Techniques [Line Items]
Investment, measurement input, recovery time	1 month 4 days	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	114 months	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	35 months 19 days	54 months 18 days