Investments - Schedule of Loans by Maturity (Details) $ in Millions	Dec. 31, 2024 USD ($) loan	Dec. 31, 2023 USD ($) loan
Cost
Total	$ 787.4	$ 144.8
Mortgage Loans
Cost
One Year or Less	34.9	19.7
Greater than One Year and Less than Three Years	103.5	34.9
Greater than Three Years and Less than Five Years	17.7	32.4
Greater than Five Years and Less than Seven Years	0.0	17.2
Greater than Seven Years and Less than Ten Years	54.0	40.6
Total	$ 210.1	$ 144.8
Loan Count
One Year or Less | loan	3	4
Greater than One Year and Less than Three Years | loan	7	6
Greater than Three Years and Less than Five Years | loan	2	6
Greater than Five Years and Less than Seven Years | loan	0	4
Greater than Seven Years and Less than Ten Years | loan	5	8
Total | loan	17	28