Segment Information - Summary of Operations by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Customer revenue	$ 440.4	$ 367.6	$ 872.4	$ 803.5
Gross profit	142.2	74.9	281.4	188.0
DWS
Segment Reporting Information [Line Items]
Customer revenue	146.5	133.5	287.6	293.7
C&I
Segment Reporting Information [Line Items]
Customer revenue	124.4	113.2	247.7	217.2
ECS
Segment Reporting Information [Line Items]
Customer revenue	169.5	120.9	337.1	292.6
Intersegment
Segment Reporting Information [Line Items]
Customer revenue	0.5	0.0	1.4	0.1
Intersegment | DWS
Segment Reporting Information [Line Items]
Customer revenue	0.0	0.0	0.0	0.0
Intersegment | C&I
Segment Reporting Information [Line Items]
Customer revenue	0.0	0.0	0.0	0.0
Intersegment | ECS
Segment Reporting Information [Line Items]
Customer revenue	0.5	0.0	1.4	0.1
Operating Segments
Segment Reporting Information [Line Items]
Customer revenue	440.9	367.6	873.8	803.6
Gross profit	142.1	71.8	275.8	176.3
Operating Segments | DWS
Segment Reporting Information [Line Items]
Customer revenue	146.5	133.5	287.6	293.7
Gross profit	22.3	9.1	40.9	16.3
Operating Segments | C&I
Segment Reporting Information [Line Items]
Customer revenue	124.4	113.2	247.7	217.2
Gross profit	15.6	5.9	27.6	3.1
Operating Segments | ECS
Segment Reporting Information [Line Items]
Customer revenue	170.0	120.9	338.5	292.7
Gross profit	$ 104.2	$ 56.8	$ 207.3	$ 156.9