Financial Derivatives (Schedule of Derivative Activity) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Interest rate swaps | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | $ 1,009,110 | $ 731,941 | $ 1,059,756 |
| TBA securities | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 713,634 | 973,331 | |
| Credit default swaps | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 277,990 | 399,316 | 566,805 |
| Total return swaps | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 6,975 | 39,434 | 53,603 |
| Futures | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 149,538 | 167,708 | 201,295 |
| Options | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 1,500 | 19,825 | 99,891 |
| Forwards | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | 26,413 | 30,930 | $ 45,522 |
| Warrants | |||
| Derivative [Line Items] | |||
| Average Monthly Notional | $ 1,570 | $ 2,222 | |