Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2018

Summary of Significant Accounting Policies

Schedule of disaggregation or revenue

	Three Months Ended September 30,								Nine Months Ended September 30,
Revenue by Service Provided	2018				2017				2018				2017
HVAC and Plumbing	$	540,733	91.0	%	$	446,035	92.8	%	$	1,448,761	90.9	%	$	1,207,434	91.0	%
Building Automation Control Systems		25,822	4.3	%		15,583	3.2	%		72,128	4.5	%		66,343	5.0	%
Other		27,981	4.7	%		19,233	4.0	%		73,631	4.6	%		53,073	4.0	%
Total	$	594,536	100.0	%	$	480,851	100.0	%	$	1,594,520	100.0	%	$	1,326,850	100.0	%
	Three Months Ended September 30,								Nine Months Ended September 30,
Revenue by Type of Customer	2018				2017				2018				2017
Industrial	$	184,174	31.0	%	$	110,569	23.0	%	$	398,351	25.0	%	$	295,939	22.3	%
Education		115,202	19.4	%		102,459	21.3	%		312,852	19.6	%		253,321	19.1	%
Office Buildings		75,871	12.8	%		49,646	10.3	%		224,300	14.1	%		178,550	13.5	%
Healthcare		79,424	13.3	%		60,427	12.6	%		214,537	13.4	%		171,516	12.9	%
Government		32,633	5.5	%		33,745	7.0	%		106,065	6.6	%		105,304	7.9	%
Retail, Restaurants and Entertainment		60,908	10.2	%		67,959	14.1	%		169,899	10.7	%		167,853	12.7	%
Multi-Family and Residential		33,903	5.7	%		29,335	6.1	%		102,995	6.5	%		86,465	6.5	%
Other		12,421	2.1	%		26,711	5.6	%		65,521	4.1	%		67,902	5.1	%
Total	$	594,536	100.0	%	$	480,851	100.0	%	$	1,594,520	100.0	%	$	1,326,850	100.0	%
	Three Months Ended September 30,								Nine Months Ended September 30,
Revenue by Activity Type	2018				2017				2018				2017
New Construction	$	232,192	39.1	%	$	170,540	35.5	%	$	599,627	37.6	%	$	497,443	37.5	%
Existing Building Construction		203,618	34.2	%		163,932	34.1	%		566,590	35.5	%		429,178	32.3	%
Service Projects		57,322	9.6	%		50,232	10.4	%		149,083	9.4	%		139,269	10.5	%
Service Calls, Maintenance and Monitoring		101,404	17.1	%		96,147	20.0	%		279,220	17.5	%		260,960	19.7	%
Total	$	594,536	100.0	%	$	480,851	100.0	%	$	1,594,520	100.0	%	$	1,326,850	100.0	%

Schedule of contract assets and liabilities

The following table presents the changes in contract assets and contract liabilities (in thousands):

	Nine Months Ended
	September 30, 2018
	Contract		Contract
	Assets		Liabilities
Balance at beginning of period	$	30,116	$	106,005
Change due to acquisitions		2,815		7,465
Change due to conditional versus unconditional		7,057		—
Reclassified to unbilled accounts receivable		(28,980)		—
Change in timing for performance obligation to be satisfied		—		17,682
Balance at September 30, 2018	$	11,008	$	131,152