Revenue from Contracts with Customers - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 3,207,598	$ 2,826,361	$ 9,143,652	$ 8,126,298
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		3,096,872	2,708,660	8,816,009	7,762,552
United States Electrical Construction And Facilities Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		697,406	633,383	2,020,319	1,719,525
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		697,766	634,327	2,022,002	1,723,090
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Network and Communications Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 236,454	$ 209,265	$ 665,493	$ 534,130
Percent of total segment revenues		34.00%	33.00%	33.00%	31.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Commercial Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 104,270	$ 106,058	$ 295,188	$ 301,908
Percent of total segment revenues		15.00%	17.00%	15.00%	17.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Manufacturing and Industrial Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 97,788	$ 78,562	$ 278,912	$ 210,331
Percent of total segment revenues		14.00%	12.00%	14.00%	12.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Healthcare Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 62,126	$ 43,911	$ 182,442	$ 119,259
Percent of total segment revenues		9.00%	7.00%	9.00%	7.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | High-Tech Manufacturing Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 33,482	$ 20,132	$ 102,075	$ 62,956
Percent of total segment revenues		5.00%	3.00%	5.00%	4.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Institutional Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 37,916	$ 46,344	$ 112,577	$ 115,799
Percent of total segment revenues		6.00%	7.00%	5.00%	7.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Transportation Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 43,287	$ 40,525	$ 118,436	$ 128,047
Percent of total segment revenues		6.00%	7.00%	6.00%	7.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Water and Wastewater Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 6,327	$ 5,466	$ 18,388	$ 15,962
Percent of total segment revenues		1.00%	1.00%	1.00%	1.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Hospitality and Entertainment Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 16,708	$ 8,598	$ 56,510	$ 19,892
Percent of total segment revenues		2.00%	1.00%	3.00%	1.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Short Duration Projects [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities	[1]	$ 43,481	$ 58,637	$ 141,901	$ 167,553
Percent of total segment revenues		6.00%	9.00%	7.00%	10.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Service Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 15,927	$ 16,829	$ 50,080	$ 47,253
Percent of total segment revenues		2.00%	3.00%	2.00%	3.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ (360)	$ (944)	$ (1,683)	$ (3,565)
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		1,329,600	1,108,655	3,602,271	3,158,948
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		1,332,747	1,111,900	3,608,595	3,167,091
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Network and Communications Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 102,630	$ 87,070	$ 289,085	$ 203,347
Percent of total segment revenues		8.00%	8.00%	8.00%	6.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Commercial Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 283,659	$ 271,908	$ 828,809	$ 799,729
Percent of total segment revenues		21.00%	25.00%	23.00%	25.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Manufacturing and Industrial Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 178,123	$ 156,524	$ 485,809	$ 461,385
Percent of total segment revenues		13.00%	14.00%	13.00%	15.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Healthcare Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 123,025	$ 120,185	$ 353,595	$ 367,002
Percent of total segment revenues		9.00%	11.00%	10.00%	12.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | High-Tech Manufacturing Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 255,229	$ 81,970	$ 549,678	$ 211,071
Percent of total segment revenues		19.00%	7.00%	15.00%	7.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Institutional Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 89,215	$ 99,066	$ 224,889	$ 251,715
Percent of total segment revenues		7.00%	9.00%	6.00%	8.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Transportation Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 10,168	$ 15,494	$ 31,615	$ 47,793
Percent of total segment revenues		1.00%	1.00%	1.00%	1.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Water and Wastewater Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 65,219	$ 66,667	$ 201,167	$ 196,157
Percent of total segment revenues		5.00%	6.00%	6.00%	6.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Hospitality and Entertainment Market Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 14,716	$ 9,910	$ 38,324	$ 34,108
Percent of total segment revenues		1.00%	1.00%	1.00%	1.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Short Duration Projects [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities	[1]	$ 81,851	$ 76,073	$ 237,246	$ 254,102
Percent of total segment revenues		6.00%	7.00%	7.00%	8.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member] | Service Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 128,912	$ 127,033	$ 368,378	$ 340,682
Percent of total segment revenues		10.00%	11.00%	10.00%	11.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ (3,147)	$ (3,245)	$ (6,324)	$ (8,143)
United States Building Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		817,718	719,383	2,318,105	2,041,555
United States Building Services [Member] | UNITED STATES | Mechanical Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 542,371	$ 471,134	$ 1,519,410	$ 1,300,555
Percent of total segment revenues		66.00%	65.00%	65.00%	64.00%
United States Building Services [Member] | UNITED STATES | Commercial Site-Based Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 222,499	$ 199,957	$ 639,193	$ 596,589
Percent of total segment revenues		27.00%	28.00%	28.00%	29.00%
United States Building Services [Member] | UNITED STATES | Government Site-Based Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 52,848	$ 48,292	$ 159,502	$ 144,411
Percent of total segment revenues		7.00%	7.00%	7.00%	7.00%
United States Industrial Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 252,148	$ 247,239	$ 875,314	$ 842,524
United States Industrial Services [Member] | UNITED STATES | Field Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 214,341	$ 213,866	$ 751,062	$ 732,826
Percent of total segment revenues		85.00%	87.00%	86.00%	87.00%
United States Industrial Services [Member] | UNITED STATES | Shop Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 37,807	$ 33,373	$ 124,252	$ 109,698
Percent of total segment revenues		15.00%	13.00%	14.00%	13.00%
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 110,726	$ 117,701	$ 327,643	$ 363,746
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM | Service Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 54,286	$ 51,762	$ 157,631	$ 170,840
Percent of total segment revenues		49.00%	44.00%	48.00%	47.00%
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM | Project Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 56,440	$ 65,939	$ 170,012	$ 192,906
Percent of total segment revenues		51.00%	56.00%	52.00%	53.00%

[1] Represents those projects which generally are completed within three months or less.