Discontinued Operations - Carrying Amounts of Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets held for sale	$ 0.0	$ 3.4
Non-current assets held for sale	0.5	0.7
Non-current liabilities held for sale	0.0	0.4
Darex | Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Trade accounts receivable	0.0	2.2
Inventories, net	0.0	1.2
Current assets held for sale	0.0	3.4
Properties and equipment, net	0.0	0.2
Other assets	0.5	0.5
Non-current assets held for sale	0.5	0.7
Underfunded and unfunded defined benefit pension plans	0.0	0.4
Non-current liabilities held for sale	$ 0.0	$ 0.4