Revenue from Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2023

Revenue from Contracts with Customers

Schedule of disaggregation of revenue

Our consolidated 2023 revenue was derived from contracts to provide service activities in the mechanical and electrical segments we serve. Refer to Note 16 “Segment Information” for additional information on our reportable segments. We disaggregate our revenue from contracts with customers by activity, customer type and service provided, as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. See details in the following tables (dollars in thousands):

	Year Ended December 31,
Revenue by Service Provided	2023				2022				2021
Mechanical Segment	$	3,946,022	75.8	%	$	3,178,475	76.8	%	$	2,542,623	82.7	%
Electrical Segment		1,260,738	24.2	%		961,889	23.2	%		531,013	17.3	%
Total	$	5,206,760	100.0	%	$	4,140,364	100.0	%	$	3,073,636	100.0	%
	Year Ended December 31,
Revenue by Type of Customer	2023				2022				2021
Manufacturing	$	1,751,684	33.6	%	$	1,426,962	34.5	%	$	970,986	31.6	%
Technology		1,114,382	21.4	%		546,290	13.2	%		385,702	12.5	%
Healthcare		554,906	10.6	%		584,023	14.1	%		417,901	13.6	%
Education		493,982	9.5	%		445,638	10.8	%		390,251	12.7	%
Office Buildings		400,754	7.7	%		349,235	8.4	%		308,799	10.1	%
Retail, Restaurants and Entertainment		310,381	6.0	%		311,697	7.5	%		213,386	6.9	%
Government		301,837	5.8	%		255,314	6.2	%		174,813	5.7	%
Multi-Family and Residential		181,780	3.5	%		126,339	3.0	%		112,779	3.7	%
Other		97,054	1.9	%		94,866	2.3	%		99,019	3.2	%
Total	$	5,206,760	100.0	%	$	4,140,364	100.0	%	$	3,073,636	100.0	%
	Year Ended December 31,
Revenue by Activity Type	2023				2022				2021
New Construction	$	2,853,239	54.8	%	$	2,011,992	48.6	%	$	1,421,784	46.3	%
Existing Building Construction		1,337,023	25.6	%		1,210,512	29.2	%		963,461	31.3	%
Service Projects		446,151	8.6	%		382,155	9.2	%		278,582	9.1	%
Service Calls, Maintenance and Monitoring		570,347	11.0	%		535,705	13.0	%		409,809	13.3	%
Total	$	5,206,760	100.0	%	$	4,140,364	100.0	%	$	3,073,636	100.0	%

Schedule of contract assets and liabilities

Contract assets and liabilities in the Consolidated Balance Sheet consisted of the following amounts as of December 31, 2023 and December 31, 2022 (in thousands):

	December 31, 2023		December 31, 2022
Contract assets:
Costs and estimated earnings in excess of billings, less allowance for credit losses	$	28,084	$	27,211
Contract liabilities:
Billings in excess of costs and estimated earnings and deferred revenue	$	909,538	$	548,293