Financial Derivatives (Schedule of Derivative Activity) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Interest rate swaps
Derivative [Line Items]
Average Monthly Notional	$ 10,336,515	$ 6,264,082
TBA securities
Derivative [Line Items]
Average Monthly Notional	399,805	443,821
Credit default swaps
Derivative [Line Items]
Average Monthly Notional	1,144,796	816,986
Futures
Derivative [Line Items]
Average Monthly Notional	204,000	292,562
Forwards
Derivative [Line Items]
Average Monthly Notional	20,555	23,575
Warrants
Derivative [Line Items]
Average Monthly Notional	104	125
Total return swaps
Derivative [Line Items]
Average Monthly Notional	100	705
Options
Derivative [Line Items]
Average Monthly Notional	$ 5,717	$ 605