Financial Derivatives (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2025	Sep. 30, 2025
Derivative [Line Items]
Spread on written credit derivatives		0.79%
Credit Default Swap, Selling Protection [Member]
Derivative [Line Items]
Total net up-front payments received	$ 0.3	$ 12.9
Minimum
Derivative [Line Items]
Spread on written credit derivatives		1.43%
Maximum
Derivative [Line Items]
Spread on written credit derivatives		3.21%