Investments - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 62.6	$ 53.3
Other comprehensive (loss) income	(14.4)	(1.6)	$ 3.7
Available-for-sale investments	61.4	54.0
Allowance for credit losses related to our available-for-sale debt securities	0.0
Available-for-sale investments, accumulated unrealized losses	1.3	0.1
Available-for-sale investments, fair value of securities with unrealized losses	53.7	12.2
Unrealized Gain (Loss) on Available-for-Sale Securities
Debt Securities, Available-for-sale [Line Items]
Other comprehensive (loss) income	(1.4)	$ (0.4)	$ 0.4
State and Local Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 62.6