Long-Term Debt - Summary of Debt Refinancing Costs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Gross cost at January 1	$ 1.8	$ 1.8
Written off	(1.8)	0.0
Capitalized in the year	1.4	0.0
Gross cost	1.4	1.8	$ 1.8
Accumulated amortization,Beginning Balance	(1.2)	(0.8)
Written off	1.4	0.0
Amortization in the year	(0.4)	(0.4)	(0.3)
Accumulated amortization,Ending balance	(0.2)	(1.2)	$ (0.8)
Deferred finance costs, net	$ 1.2	$ 0.6