Investment in Securities (Summary of Investment Income) (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
| Securities, Available-for-sale [Line Items] | ||||
| Interest Income | $ 40,146 | $ 43,075 | $ 126,115 | $ 134,463 |
| Agency RMBS | ||||
| Securities, Available-for-sale [Line Items] | ||||
| Coupon Interest | 14,797 | 14,117 | 43,449 | 47,632 |
| Net Amortization | (9,551) | (7,454) | (20,123) | (25,516) |
| Interest Income | 5,246 | 6,663 | 23,326 | 22,116 |
| Non-Agency RMBS and CMBS | ||||
| Securities, Available-for-sale [Line Items] | ||||
| Coupon Interest | 3,307 | 3,311 | 10,321 | 10,995 |
| Net Amortization | 748 | 1,911 | 3,179 | 4,001 |
| Interest Income | 4,055 | 5,222 | 13,500 | 14,996 |
| CLOs | ||||
| Securities, Available-for-sale [Line Items] | ||||
| Coupon Interest | 3,532 | 2,256 | 7,978 | 11,662 |
| Net Amortization | (1,456) | 2,179 | 59 | 1,543 |
| Interest Income | 2,076 | 4,435 | 8,037 | 13,205 |
| Other Securities | ||||
| Securities, Available-for-sale [Line Items] | ||||
| Coupon Interest | 4,590 | 2,970 | 12,296 | 8,992 |
| Net Amortization | (1,813) | (1,435) | (3,796) | (3,584) |
| Interest Income | 2,777 | 1,535 | 8,500 | 5,408 |
| Securities Investment [Member] | ||||
| Securities, Available-for-sale [Line Items] | ||||
| Coupon Interest | 26,226 | 22,654 | 74,044 | 79,281 |
| Net Amortization | (12,072) | (4,799) | (20,681) | (23,556) |
| Interest Income | $ 14,154 | $ 17,855 | $ 53,363 | $ 55,725 |