Goodwill and Other Intangible Assets - Components of Other Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 11.4	$ 11.4
Accumulated Amortization	(3.8)	(3.6)
Net Book Value	7.6	7.8
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	10.4	10.4
Accumulated Amortization	(3.0)	(2.8)
Net Book Value	7.4	7.6
Trade Names
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	1.0	1.0
Accumulated Amortization	(0.8)	(0.8)
Net Book Value	$ 0.2	$ 0.2