Revenue Recognition - Schedule of Revenue by Contract Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Contract revenues	$ 2,498,289	$ 2,247,392	$ 2,071,159
Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	100.00%	100.00%	100.00%
Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 1,523,338	$ 1,411,658	$ 1,265,401
Fixed price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	61.00%	62.80%	61.10%
Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 443,536	$ 415,942	$ 281,781
Unit price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	17.70%	18.50%	13.60%
T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 531,415	$ 419,792	$ 523,977
T&E | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	21.30%	18.70%	25.30%
T&D
Disaggregation of Revenue [Line Items]
Contract revenues	$ 1,301,587	$ 1,154,378	$ 1,134,411
T&D | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	100.00%	100.00%	100.00%
T&D | Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 559,861	$ 507,634	$ 564,266
T&D | Fixed price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	43.00%	44.00%	49.70%
T&D | Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 369,710	$ 338,611	$ 228,229
T&D | Unit price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	28.40%	29.30%	20.10%
T&D | T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 372,016	$ 308,133	$ 341,916
T&D | T&E | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	28.60%	26.70%	30.20%
C&I
Disaggregation of Revenue [Line Items]
Contract revenues	$ 1,196,702	$ 1,093,014	$ 936,748
C&I | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	100.00%	100.00%	100.00%
C&I | Fixed price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 963,477	$ 904,024	$ 701,135
C&I | Fixed price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	80.50%	82.70%	74.80%
C&I | Unit price
Disaggregation of Revenue [Line Items]
Contract revenues	$ 73,826	$ 77,331	$ 53,552
C&I | Unit price | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	6.20%	7.10%	5.70%
C&I | T&E
Disaggregation of Revenue [Line Items]
Contract revenues	$ 159,399	$ 111,659	$ 182,061
C&I | T&E | Product Concentration Risk | Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk	13.30%	10.20%	19.50%