Income Taxes - Deferred Income Taxes (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Assets
Income tax loss carryforwards	$ 17.8	$ 17.7
Other accrued liabilities	1.2	1.3
Employee benefits related	1.2	0.9
Insurance related	0.8	1.0
Goodwill	0.2	0.3
Inventories	1.5	1.1
Accounts receivables	0.5	0.2
Other, assets	1.6	0.5
Gross deferred tax assets	24.8	23.0
Valuation allowance	(7.3)	(7.1)
Deferred Tax Assets, Total	17.5	15.9
Liabilities
Property, plant and equipment	0.1	0.1
LIFO	6.0	5.8
Other, liabilities	0.3	0.3
Gross deferred tax liabilities	6.4	6.2
Deferred Tax Liabilities, Total	$ 6.4	$ 6.2