Financial Derivatives (Schedule of Derivative Activity) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2023	Jun. 30, 2022
Interest rate swaps
Derivative [Line Items]
Average Monthly Notional	$ 4,283,193	$ 3,292,243
TBA securities
Derivative [Line Items]
Average Monthly Notional	721,556	796,003
Credit default swaps
Derivative [Line Items]
Average Monthly Notional	254,288	130,819
Total return swaps
Derivative [Line Items]
Average Monthly Notional	0	688
Futures
Derivative [Line Items]
Average Monthly Notional	300,675	186,446
Options
Derivative [Line Items]
Average Monthly Notional	0	13,846
Forwards
Derivative [Line Items]
Average Monthly Notional	12,253	13,676
Warrants
Derivative [Line Items]
Average Monthly Notional	$ 3,110	$ 3,378