Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Concentration of Credit Risk
Deductions from allowance for doubtful accounts, net of recoveries	$ 0.7	$ 0.4	$ 0.5
Inventories
Percentage of LIFO Inventory	30.00%
Cost valuation of inventory if FIFO had been used exclusively	$ 5.6	4.7
LIFO inventories increased (decreased) cost of sales	(0.1)	0.1	(0.1)
Capitalized Computer Software, Gross	6.9	6.2
Capitalized Computer Software, Amortization	1.0	0.6	0.5
Cash and Cash Equivalents
Accrued capital expenditures excluded from investing activities	0.6	0.1	6.6
Selling Expense [Member]
Concentration of Credit Risk
Expense for bad debts	0.7	0.8	0.3
Shipping and handling
Shipping and handling expenses	8.2	8.9	8.5
Cost of Sales [Member]
Shipping and handling
Shipping and handling expenses	$ 6.0	$ 6.1	$ 6.2
Customer 1 [Member] | Sales [Member] | Customer Concentration Risk [Member]
Concentration of Credit Risk
Concentration risk percentage	5.00%
Maximum [Member] | Customer 2 [Member] | Sales [Member] | Customer Concentration Risk [Member]
Concentration of Credit Risk
Concentration risk percentage	4.00%
Canada [Member] | Sales [Member] | Customer Concentration Risk [Member]
Concentration of Credit Risk
Concentration risk percentage	2.40%	4.60%	5.50%
Estimate of Fair Value, Fair Value Disclosure [Member] | Less unamortized deferred financing fees [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Notes payable, fair value disclosure	$ 78.0	$ 98.0