Investments - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) Security	Dec. 31, 2022 USD ($) Security	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Debt Securities	$ 29.1	$ 28.8
Equity investment in a non-consolidated subsidiary	2.5
Available-for-sale debt securities	$ 10.6	$ 6.4
Number of securities in unrealized loss position | Security	28	33
Proceeds from sale of investment in fixed maturity securities	$ 7.4	$ 7.3
Maturing time deposits	5.8
Proceeds from sale of Other Investments	13.2	7.4
Payments to acquire investments	7.2	0.1	$ 12.4
Investments on deposit with the state insurance department	4.3
U.S. Treasury securities, obligations of U.S. Government agencies and municipalities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Debt Securities	24.4	21.0
Corporate Debt Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Debt Securities	4.7	7.8
Bank Time Deposits
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities	$ 0.4	$ 5.6