Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Federal and state tax loss carryforwards, expiring in 2024 to 2043	$ 19.2	$ 22.6
Tax credits	16.9	17.4
Reserves, including insurance and environmental	10.4	9.3
Interest disallowance	10.2	6.4
Accrued employee compensation	8.1	6.5
Inventory	7.6	4.6
Foreign tax loss carryforwards	7.4	6.6
Pension and other postretirement benefits obligations	7.2	8.2
Asset retirement obligations	5.6	5.3
Other	8.3	4.6
Valuation allowance	(43.1)	(43.8)
Total deferred tax assets	57.8	47.7
Deferred tax liabilities:
Tax over book depreciation and amortization	69.9	52.3
Gain on derivative contracts	0.0	0.7
Other	3.4	4.5
Total deferred tax liabilities	73.3	57.5
Net deferred tax liabilities	$ (15.5)	$ (9.8)