Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Discontinued operations and dispositions - (Loss) income before income taxes attributable to the Environmental Sciences business (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Environmental Sciences Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income before income taxes		$ 8.9		$ 23.6
Industrial Services Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income before income taxes	$ (2.6)	$ (0.8)	$ (5.5)	$ (26.9)