Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue
Revenue	$ 1,017,948	$ 713,895	$ 1,903,164	$ 1,383,656
Percentage of revenue from contract with customer (as a percent)	100.00%	100.00%	100.00%	100.00%
Industrial
Disaggregation of Revenue
Revenue	$ 470,491	$ 311,075	$ 880,675	$ 580,658
Percentage of revenue from contract with customer (as a percent)	46.20%	43.60%	46.30%	42.00%
Education
Disaggregation of Revenue
Revenue	$ 119,248	$ 92,381	$ 208,694	$ 184,838
Percentage of revenue from contract with customer (as a percent)	11.70%	12.90%	11.00%	13.40%
Office Buildings
Disaggregation of Revenue
Revenue	$ 85,917	$ 73,014	$ 161,032	$ 152,010
Percentage of revenue from contract with customer (as a percent)	8.40%	10.20%	8.50%	11.00%
Healthcare
Disaggregation of Revenue
Revenue	$ 141,113	$ 96,004	$ 275,908	$ 191,095
Percentage of revenue from contract with customer (as a percent)	13.90%	13.40%	14.50%	13.80%
Government
Disaggregation of Revenue
Revenue	$ 66,212	$ 42,506	$ 123,677	$ 85,671
Percentage of revenue from contract with customer (as a percent)	6.50%	6.00%	6.50%	6.20%
Retail, Restaurants and Entertainment
Disaggregation of Revenue
Revenue	$ 80,434	$ 48,933	$ 146,016	$ 93,509
Percentage of revenue from contract with customer (as a percent)	7.90%	6.90%	7.70%	6.70%
Multi-Family and Residential
Disaggregation of Revenue
Revenue	$ 30,172	$ 28,341	$ 54,614	$ 53,001
Percentage of revenue from contract with customer (as a percent)	3.00%	4.00%	2.80%	3.80%
Other
Disaggregation of Revenue
Revenue	$ 24,361	$ 21,641	$ 52,548	$ 42,874
Percentage of revenue from contract with customer (as a percent)	2.40%	3.00%	2.70%	3.10%
New Construction
Disaggregation of Revenue
Revenue	$ 484,913	$ 329,890	$ 914,331	$ 631,951
Percentage of revenue from contract with customer (as a percent)	47.70%	46.20%	48.10%	45.70%
Existing Building Construction
Disaggregation of Revenue
Revenue	$ 304,316	$ 215,317	$ 563,601	$ 431,918
Percentage of revenue from contract with customer (as a percent)	29.90%	30.20%	29.60%	31.20%
Service Projects
Disaggregation of Revenue
Revenue	$ 93,972	$ 66,263	$ 170,224	$ 126,323
Percentage of revenue from contract with customer (as a percent)	9.20%	9.30%	8.90%	9.10%
Service Calls, Maintenance and Monitoring
Disaggregation of Revenue
Revenue	$ 134,747	$ 102,425	$ 255,008	$ 193,464
Percentage of revenue from contract with customer (as a percent)	13.20%	14.30%	13.40%	14.00%
Mechanical Services
Disaggregation of Revenue
Revenue	$ 776,757	$ 611,796	$ 1,459,268	$ 1,177,416
Percentage of revenue from contract with customer (as a percent)	76.30%	85.70%	76.70%	85.10%
Electrical Services
Disaggregation of Revenue
Revenue	$ 241,191	$ 102,099	$ 443,896	$ 206,240
Percentage of revenue from contract with customer (as a percent)	23.70%	14.30%	23.30%	14.90%