Investment in Securities (Summary of Investment Income) (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2020 |
Mar. 31, 2019 |
|
| Securities, Available-for-sale [Line Items] | ||
| Interest Income | $ 52,108 | $ 36,016 |
| Agency RMBS | ||
| Securities, Available-for-sale [Line Items] | ||
| Coupon Interest | 20,912 | 12,190 |
| Net Amortization | (8,844) | (4,628) |
| Interest Income | 12,068 | 7,562 |
| Non-Agency RMBS and CMBS | ||
| Securities, Available-for-sale [Line Items] | ||
| Coupon Interest | 4,053 | 3,849 |
| Net Amortization | 713 | 547 |
| Interest Income | 4,766 | 4,396 |
| CLOs | ||
| Securities, Available-for-sale [Line Items] | ||
| Coupon Interest | 5,419 | 4,244 |
| Net Amortization | (1,011) | 65 |
| Interest Income | 4,408 | 4,309 |
| Other Securities | ||
| Securities, Available-for-sale [Line Items] | ||
| Coupon Interest | 2,925 | 1,593 |
| Net Amortization | (1,045) | (562) |
| Interest Income | 1,880 | 1,031 |
| Securities Investment [Member] | ||
| Securities, Available-for-sale [Line Items] | ||
| Coupon Interest | 33,309 | 21,876 |
| Net Amortization | (10,187) | (4,578) |
| Interest Income | $ 23,122 | $ 17,298 |