Investments - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 70.1	$ 65.3
Other comprehensive (loss) income	(74.1)	32.8	$ (14.4)
Available-for-sale investments	69.6	65.0
Allowance for credit losses related to our available-for-sale debt securities	0.0
Available-for-sale investments, accumulated unrealized losses	0.6	0.6
Available-for-sale investments, fair value of securities with unrealized losses	40.5	34.5
Unrealized Gain (Loss) on Available-for-Sale Securities
Debt Securities, Available-for-sale [Line Items]
Other comprehensive (loss) income	(0.1)	$ 0.6	$ (1.4)
State and Local Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 70.1