Revenue from Contracts with Customers - Disaggregation of Revenue (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
Revenue	$ 1,378,124	$ 1,120,012	$ 3,849,194	$ 3,023,176
Percentage of revenue from contract with customer (as a percent)	100.00%	100.00%	100.00%	100.00%
Manufacturing
Disaggregation of Revenue
Revenue	$ 469,173	$ 376,505	$ 1,271,348	$ 1,029,647
Percentage of revenue from contract with customer (as a percent)	34.00%	33.60%	33.00%	34.10%
Technology
Disaggregation of Revenue
Revenue	$ 303,847	$ 165,717	$ 795,327	$ 393,250
Percentage of revenue from contract with customer (as a percent)	22.00%	14.80%	20.70%	13.00%
Healthcare
Disaggregation of Revenue
Revenue	$ 133,130	$ 147,234	$ 431,329	$ 423,142
Percentage of revenue from contract with customer (as a percent)	9.70%	13.20%	11.20%	14.00%
Education
Disaggregation of Revenue
Revenue	$ 139,206	$ 133,422	$ 376,637	$ 342,116
Percentage of revenue from contract with customer (as a percent)	10.10%	11.90%	9.80%	11.30%
Office Buildings
Disaggregation of Revenue
Revenue	$ 104,937	$ 94,931	$ 299,103	$ 255,963
Percentage of revenue from contract with customer (as a percent)	7.60%	8.50%	7.80%	8.50%
Retail, Restaurants and Entertainment
Disaggregation of Revenue
Revenue	$ 77,802	$ 84,354	$ 234,779	$ 230,370
Percentage of revenue from contract with customer (as a percent)	5.60%	7.50%	6.10%	7.60%
Government
Disaggregation of Revenue
Revenue	$ 85,220	$ 63,070	$ 227,232	$ 186,747
Percentage of revenue from contract with customer (as a percent)	6.30%	5.60%	5.90%	6.20%
Multi-Family and Residential
Disaggregation of Revenue
Revenue	$ 45,523	$ 34,310	$ 136,825	$ 88,924
Percentage of revenue from contract with customer (as a percent)	3.30%	3.10%	3.50%	2.90%
Other
Disaggregation of Revenue
Revenue	$ 19,286	$ 20,469	$ 76,614	$ 73,017
Percentage of revenue from contract with customer (as a percent)	1.40%	1.80%	2.00%	2.40%
New Construction
Disaggregation of Revenue
Revenue	$ 798,289	$ 524,122	$ 2,108,153	$ 1,438,453
Percentage of revenue from contract with customer (as a percent)	57.90%	46.80%	54.80%	47.60%
Existing Building Construction
Disaggregation of Revenue
Revenue	$ 305,795	$ 346,683	$ 974,085	$ 910,284
Percentage of revenue from contract with customer (as a percent)	22.20%	31.00%	25.30%	30.10%
Service Projects
Disaggregation of Revenue
Revenue	$ 117,202	$ 103,439	$ 335,053	$ 273,663
Percentage of revenue from contract with customer (as a percent)	8.50%	9.20%	8.70%	9.00%
Service Calls, Maintenance and Monitoring
Disaggregation of Revenue
Revenue	$ 156,838	$ 145,768	$ 431,903	$ 400,776
Percentage of revenue from contract with customer (as a percent)	11.40%	13.00%	11.20%	13.30%
Mechanical Segment [Member]
Disaggregation of Revenue
Revenue	$ 1,031,310	$ 858,768	$ 2,925,848	$ 2,318,036
Percentage of revenue from contract with customer (as a percent)	74.80%	76.70%	76.00%	76.70%
Electrical Segment [Member]
Disaggregation of Revenue
Revenue	$ 346,814	$ 261,244	$ 923,346	$ 705,140
Percentage of revenue from contract with customer (as a percent)	25.20%	23.30%	24.00%	23.30%