Revenue from Contracts with Customers - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 3,045,622	$ 2,707,388	$ 5,936,054	$ 5,299,937
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		2,939,575	2,592,840	5,719,137	5,053,892
United States Electrical Construction And Facilities Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		678,167	564,112	1,322,913	1,086,142
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		678,709	565,753	1,324,236	1,088,763
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		$ 215,288	$ 179,491	$ 429,039	$ 324,865
Percent of total segment revenues		32.00%	32.00%	32.00%	30.00%
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		$ 93,820	$ 94,009	$ 190,918	$ 195,850
Percent of total segment revenues		14.00%	16.00%	14.00%	18.00%
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		$ 95,883	$ 65,304	$ 181,124	$ 131,769
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		$ 64,813	$ 43,278	$ 120,316	$ 75,348
Percent of total segment revenues		9.00%	8.00%	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		$ 38,039	$ 22,955	$ 68,593	$ 42,824
Percent of total segment revenues		6.00%	4.00%	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		$ 37,250	$ 37,689	$ 74,661	$ 69,455
Percent of total segment revenues		5.00%	7.00%	6.00%	6.00%
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		$ 41,247	$ 42,440	$ 75,149	$ 87,522
Percent of total segment revenues		6.00%	7.00%	6.00%	8.00%
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		$ 4,603	$ 5,184	$ 12,061	$ 10,496
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		$ 19,750	$ 5,440	$ 39,802	$ 11,294
Percent of total segment revenues		3.00%	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]	$ 50,740	$ 52,868	$ 98,420	$ 108,916
Percent of total segment revenues		7.00%	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		$ 17,276	$ 17,095	$ 34,153	$ 30,424
Percent of total segment revenues		3.00%	3.00%	3.00%	3.00%
United States Electrical Construction And Facilities Services [Member] | UNITED STATES | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ (542)	$ (1,641)	$ (1,323)	$ (2,621)
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		1,194,113	1,057,649	2,272,671	2,050,293
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		1,195,812	1,060,279	2,275,848	2,055,191
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		$ 87,034	$ 60,643	$ 186,455	$ 116,277
Percent of total segment revenues		7.00%	6.00%	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		$ 289,304	$ 266,321	$ 545,150	$ 527,821
Percent of total segment revenues		24.00%	25.00%	24.00%	26.00%
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		$ 166,051	$ 155,290	$ 307,686	$ 304,861
Percent of total segment revenues		14.00%	15.00%	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		$ 117,842	$ 126,985	$ 230,570	$ 246,817
Percent of total segment revenues		10.00%	12.00%	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		$ 177,653	$ 71,528	$ 294,449	$ 129,101
Percent of total segment revenues		15.00%	7.00%	13.00%	6.00%
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		$ 71,626	$ 86,727	$ 135,674	$ 152,649
Percent of total segment revenues		6.00%	8.00%	6.00%	7.00%
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		$ 9,229	$ 16,246	$ 21,447	$ 32,299
Percent of total segment revenues		1.00%	1.00%	1.00%	2.00%
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		$ 67,286	$ 67,746	$ 135,948	$ 129,490
Percent of total segment revenues		6.00%	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		$ 13,531	$ 11,418	$ 23,608	$ 24,198
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]	$ 73,978	$ 84,470	$ 155,395	$ 178,029
Percent of total segment revenues		6.00%	8.00%	7.00%	9.00%
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		$ 122,278	$ 112,905	$ 239,466	$ 213,649
Percent of total segment revenues		10.00%	11.00%	11.00%	10.00%
United States Mechanical Construction And Facilities Services [Member] | UNITED STATES | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ (1,699)	$ (2,630)	$ (3,177)	$ (4,898)
United States Building Services [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		775,012	686,545	1,500,387	1,322,172
United States Building Services [Member] | UNITED STATES | Mechanical Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 514,505	$ 448,024	$ 977,039	$ 829,421
Percent of total segment revenues		66.00%	65.00%	65.00%	63.00%
United States Building Services [Member] | UNITED STATES | Commercial Site-Based Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 207,323	$ 193,082	$ 416,694	$ 396,632
Percent of total segment revenues		27.00%	28.00%	28.00%	30.00%
United States Building Services [Member] | UNITED STATES | Government Site-Based Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 53,184	$ 45,439	$ 106,654	$ 96,119
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		$ 292,283	$ 284,534	$ 623,166	$ 595,285
United States Industrial Services [Member] | UNITED STATES | Field Services [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 250,877	$ 247,542	$ 536,721	$ 518,960
Percent of total segment revenues		86.00%	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		$ 41,406	$ 36,992	$ 86,445	$ 76,325
Percent of total segment revenues		14.00%	13.00%	14.00%	13.00%
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 106,047	$ 114,548	$ 216,917	$ 246,045
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM | Service Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 51,682	$ 54,261	$ 103,345	$ 119,078
Percent of total segment revenues		49.00%	47.00%	48.00%	48.00%
United Kingdom Building Services [Member] [Member] | UNITED KINGDOM | Project Work [Member]
Disaggregation of Revenue [Line Items]
Revenues from unrelated entities		$ 54,365	$ 60,287	$ 113,572	$ 126,967
Percent of total segment revenues		51.00%	53.00%	52.00%	52.00%

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