Discontinued Operations - Reconciliation of Gain on Disposal (Details) - Darex - Disposed of by Sale $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds included in gain	$ 12.7
Net assets derecognized	(3.1)
Gain recognized before income taxes	9.6
Tax effect of gain recognized	(2.4)
Gain recognized after income taxes	$ 7.2

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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