Income Taxes - Deferred Income Taxes (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Income tax loss carryforwards	$ 17.0	$ 17.8
Other accrued liabilities	1.7	1.0
Employee benefits related	1.9	0.8
Insurance related	0.7	0.7
Goodwill	0.5	0.4
Intangibles	0.5
Inventories	1.4	1.8
Accounts receivables	0.7	0.8
Leases	8.4	9.7
Other, assets	0.1	2.4
Gross deferred tax assets	32.9	35.4
Valuation allowance	(18.1)	(20.0)
Deferred Tax Assets, Total	14.8	15.4
Liabilities
Property, plant and equipment	0.3	0.2
Insurance related	0.6
LIFO	5.6	5.2
Leases	8.3	9.6
Other, liabilities		0.4
Gross deferred tax liabilities	14.8	15.4
Deferred Tax Liabilities, Total	$ 14.8	$ 15.4