Investments - Schedule of Loans by Maturity (Details) $ in Millions	Dec. 31, 2023 USD ($) loan	Dec. 31, 2022 USD ($) loan
Investments, Debt and Equity Securities [Abstract]
One Year or Less | $	$ 19.7
Greater than One Year and Less than Three | $	34.9	$ 54.8
Greater than Three Years and Less than Five Years | $	32.4	33.8
Greater than Five Years and Less than Seven Years | $	17.2	20.4
Greater than Seven Years and Less than Ten Years | $	40.6	50.9
Total | $	$ 144.8	$ 159.9
One Year or Less | loan	4
Greater than One Year and Less than Three | loan	6	10
Greater than Three Years and Less than Five Years | loan	6	6
Greater than Five Years and Less than Seven Years | loan	4	4
Greater than Seven Years and Less than Ten Years | loan	8	8
Total | loan	28	28