Segment Information - Summary of Operations by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Customer revenue	$ 409.4	$ 411.8	$ 1,281.8	$ 1,215.3
Gross profit	126.9	119.9	408.3	307.9
DWS
Segment Reporting Information [Line Items]
Customer revenue	141.3	148.3	428.9	442.0
C&I
Segment Reporting Information [Line Items]
Customer revenue	118.9	116.9	366.6	334.1
ECS
Segment Reporting Information [Line Items]
Customer revenue	149.2	146.6	486.3	439.2
Intersegment
Segment Reporting Information [Line Items]
Customer revenue	0.0	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	0.0	0.0	(1.4)	(0.1)
Operating Segments
Segment Reporting Information [Line Items]
Customer revenue	409.4	411.8	1,283.2	1,215.4
Gross profit	123.1	101.2	398.9	277.5
Operating Segments | DWS
Segment Reporting Information [Line Items]
Customer revenue	141.3	148.3	428.9	442.0
Gross profit	16.8	21.6	57.7	37.9
Operating Segments | C&I
Segment Reporting Information [Line Items]
Customer revenue	118.9	116.9	366.6	334.1
Gross profit	9.3	4.3	36.9	7.4
Operating Segments | ECS
Segment Reporting Information [Line Items]
Customer revenue	149.2	146.6	487.7	439.3
Gross profit	$ 97.0	$ 75.3	$ 304.3	$ 232.2