Derivative Financial Instruments - Schedule of Net Change in Net Unrealized Gains (Losses) to Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Derivative [Line Items]
Net realized gains/(losses)	$ (0.7)	$ (4.7)	$ 0.0	$ (16.7)
Change in net unrealized gains/(losses)	1.9	4.4	2.0	0.5
Credit default swaps
Derivative [Line Items]
Net realized gains/(losses)	0.0	0.0	0.1	0.0
Change in net unrealized gains/(losses)	0.0	(0.1)	0.0	(0.1)
Forwards
Derivative [Line Items]
Net realized gains/(losses)	(0.7)	(4.7)	(0.1)	(16.7)
Change in net unrealized gains/(losses)	$ 1.9	$ 4.5	$ 2.0	$ 0.6

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.