Revenue Recognition - Schedule of revenue by market type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Contract revenues	$ 708,114	$ 649,573	$ 1,344,738	$ 1,242,059
Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	100.00%	100.00%	100.00%	100.00%
T&D
Disaggregation of Revenue [Line Items]
Contract revenues	$ 415,235	$ 326,831	$ 780,091	$ 641,739
T&D | Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	100.00%	100.00%	100.00%	100.00%
T&D | Transmission
Disaggregation of Revenue [Line Items]
Contract revenues	$ 250,078	$ 210,946	$ 471,685	$ 422,173
T&D | Transmission | Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	35.30%	32.50%	35.10%	34.00%
T&D | Distribution
Disaggregation of Revenue [Line Items]
Contract revenues	$ 165,157	$ 115,885	$ 308,406	$ 219,566
T&D | Distribution | Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	23.30%	17.80%	22.90%	17.70%
C&I
Disaggregation of Revenue [Line Items]
Contract revenues	$ 292,879	$ 322,742	$ 564,647	$ 600,320
C&I | Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	100.00%	100.00%	100.00%	100.00%
C&I | Electrical construction
Disaggregation of Revenue [Line Items]
Contract revenues	$ 292,879	$ 322,742	$ 564,647	$ 600,320
C&I | Electrical construction | Product concentration risk | Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, Percent	41.40%	49.70%	42.00%	48.30%