Supplemental Data - Advertising and Research and Development, Accounts Receivable, Inventory, Prepaid and Other Current Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Advertising and Research Development Expenses
Advertising expense	$ 4.9	$ 4.7	$ 6.0
Research and development expense	8.7	9.2	$ 8.9
Accounts Receivable - net
From customers	104.1	116.1
Less allowance for doubtful accounts and sales discounts	(1.5)	(1.3)
Total	102.6	114.8
Inventories by Major Class:
Raw materials	32.8	35.6
Work in progress	26.4	30.1
Finished goods	67.3	78.3
Supplies and other	5.2	3.0
Inventories, gross	131.7	147.0
Excess of FIFO over LIFO cost	(8.9)	(15.4)
Total	122.8	131.6
FIFO values of inventories valued on the LIFO method	102.2	109.1
Decrease in LIFO inventory quantities	0.1	0.6
Prepaid and Other Current Assets
Prepaid and other current assets	9.9	12.2
Spare parts	6.4	6.6
Receivable for income taxes	2.0	2.8
Total	$ 18.3	$ 21.6