Revenue Recognition - Schedule of revenue by contract type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of Revenue [Line Items]
Contract revenues	$ 1,081,727	$ 900,325	$ 2,082,107	$ 1,733,945
Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	100.00%	100.00%	100.00%	100.00%
Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 647,904	$ 508,100	$ 1,192,803	$ 975,355
Fixed price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	59.90%	56.40%	57.30%	56.30%
Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 222,678	$ 211,268	$ 453,819	$ 381,037
Unit price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	20.60%	23.50%	21.80%	22.00%
T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 211,145	$ 180,957	$ 435,485	$ 377,553
T&E \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	19.50%	20.10%	20.90%	21.70%
T&D
Disaggregation of Revenue [Line Items]
Contract revenues	$ 524,022	$ 506,273	$ 1,064,992	$ 968,043
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 \| Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 158,637	$ 178,118	$ 308,815	$ 351,568
T&D \| Fixed price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	30.30%	35.20%	29.00%	36.30%
T&D \| Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 208,407	$ 191,022	$ 426,618	$ 343,124
T&D \| Unit price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	39.80%	37.70%	40.10%	35.40%
T&D \| T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 156,978	$ 137,133	$ 329,559	$ 273,351
T&D \| T&E \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	29.90%	27.10%	30.90%	28.30%
C&I
Disaggregation of Revenue [Line Items]
Contract revenues	$ 557,705	$ 394,052	$ 1,017,115	$ 765,902
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 \| Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 489,267	$ 329,982	$ 883,988	$ 623,787
C&I \| Fixed price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	87.70%	83.80%	86.90%	81.40%
C&I \| Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 14,271	$ 20,246	$ 27,201	$ 37,913
C&I \| Unit price \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	2.60%	5.10%	2.70%	5.00%
C&I \| T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 54,167	$ 43,824	$ 105,926	$ 104,202
C&I \| T&E \| Product concentration risk \| Revenue benchmark
Disaggregation of Revenue [Line Items]
Concentration risk, percent	9.70%	11.10%	10.40%	13.60%