Financial Derivatives Narrative (Details) - USD ($) $ in Thousands |
Sep. 30, 2021 |
Dec. 31, 2020 |
---|---|---|
Derivative [Line Items] | ||
U.S. Treasury securities sold short, at fair value | $ 9,974 | $ 0 |
US Treasury Securities [Member] | ||
Derivative [Line Items] | ||
U.S. Treasury securities sold short, at fair value | 10,000 | |
Investment Sold, Not yet Purchased, Balance, Principal Amount | $ 10,000 |