Discontinued operations and dispositions - Operating results of discontinues operations (Details) - Nexeo Plastics - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
External sales	$ 0.0	$ 156.9
Cost of goods sold (exclusive of depreciation)	0.0	136.7
Outbound freight and handling	0.0	3.5
Warehousing, selling and administrative	0.0	7.9
Other expenses	0.0	1.4
Income from discontinued operations before income taxes	0.0	7.4
Income tax expense from discontinued operations	0.7	2.0
Net (loss) income from discontinued operations	$ (0.7)	$ 5.4