Contingencies and Commitments (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Remaining minimum amount committed	$ 449.9	$ 449.9	$ 502.6
Non-core Legacy Commercial exposures (after-tax)		(15.7)
Corporate & Other
Loss Contingencies [Line Items]
Non-core Legacy Commercial exposures (after-tax)		$ (15.7)
Operating Segments | Corporate & Other
Loss Contingencies [Line Items]
Non-core Legacy Commercial exposures (after-tax)	$ 15.7