Acquisitions, Goodwill and Other Intangible Assets - Rollforward of Goodwill by Segment (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Goodwill [Line Items]
Goodwill		$ 1,645,300
Accumulated impairment loss		(124,700)
Goodwill, net	$ 1,484,600	1,520,575
Goodwill [Roll Forward]
Goodwill, net, beginning balance	1,520,575
Goodwill, acquired during period	7,100
Goodwill, measurement period adjustments	(42,800)
Goodwill, currency translation adjustments	(300)
Goodwill, net, ending balance	1,484,600	1,520,575
HMG
Goodwill [Line Items]
Goodwill, net		68,300
Goodwill [Roll Forward]
Goodwill, net, beginning balance	68,300
Goodwill, net, ending balance		68,300
Communications
Goodwill [Line Items]
Goodwill		614,500
Accumulated impairment loss		0
Goodwill, net	604,800	614,500
Goodwill [Roll Forward]
Goodwill, net, beginning balance	614,500
Goodwill, acquired during period	3,000
Goodwill, measurement period adjustments	(12,700)
Goodwill, currency translation adjustments	0
Goodwill, net, ending balance	604,800	614,500
Communications | HMG
Goodwill [Roll Forward]
Goodwill, period increase (decrease)		13,000
Clean Energy and Infrastructure
Goodwill [Line Items]
Goodwill		166,100
Accumulated impairment loss
Goodwill, net	168,200	166,100
Goodwill [Roll Forward]
Goodwill, net, beginning balance	166,100
Goodwill, acquired during period	0
Goodwill, measurement period adjustments	2,100
Goodwill, currency translation adjustments	0
Goodwill, net, ending balance	168,200	166,100
Oil and Gas
Goodwill [Line Items]
Goodwill		561,300
Accumulated impairment loss		(124,700)
Goodwill, net	447,100	436,600
Goodwill [Roll Forward]
Goodwill, net, beginning balance	436,600
Goodwill, acquired during period	4,100
Goodwill, measurement period adjustments	6,700
Goodwill, currency translation adjustments	(300)
Goodwill, net, ending balance	447,100	436,600
Oil and Gas | HMG
Goodwill [Roll Forward]
Goodwill, period increase (decrease)		10,400
Power Delivery
Goodwill [Line Items]
Goodwill		303,400
Accumulated impairment loss		0
Goodwill, net	264,500	303,400
Goodwill [Roll Forward]
Goodwill, net, beginning balance	303,400
Goodwill, acquired during period	0
Goodwill, measurement period adjustments	(38,900)
Goodwill, currency translation adjustments	0
Goodwill, net, ending balance	$ 264,500	303,400
Power Delivery | HMG
Goodwill [Roll Forward]
Goodwill, period increase (decrease)		$ 23,400