Acquisitions and Dispositions - Pro Forma Information (Details) - Clean Earth and ESOL - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition [Line Items]
Pro forma revenues	$ 447.3	$ 564.4	$ 976.8	$ 1,078.1
Pro forma net income (including discontinued operations)	$ 2.0	$ 23.5	$ 2.7	$ 12.8