Goodwill and Intangible Assets - Summary of Indefinite-Lived Intangibles (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Indefinite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 13.4	$ 10.8	$ 10.8
Impairments	0.0	(0.3)	0.0
Acquisitions	0.0	2.9	0.0
Ending balance	13.4	13.4	10.8
Trade Names
Indefinite-lived Intangible Assets [Roll Forward]
Beginning balance	7.6	7.9	7.9
Impairments	0.0	(0.3)	0.0
Acquisitions	0.0	0.0	0.0
Ending balance	7.6	7.6	7.9
State Licenses
Indefinite-lived Intangible Assets [Roll Forward]
Beginning balance	5.8	2.9	2.9
Impairments	0.0	0.0	0.0
Acquisitions	0.0	2.9	0.0
Ending balance	$ 5.8	$ 5.8	$ 2.9