Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Summary of Significant Accounting Policies

Schedule of disaggregation or revenue

	Three Months Ended March 31,
Revenue by Service Provided	2018				2017
HVAC and Plumbing	$	424,017	91	%	$	338,723	89	%
Building Automation Control Systems		20,045	4	%		22,835	6	%
Other		20,879	5	%		19,030	5	%
Total	$	464,941	100	%	$	380,588	100	%
	Three Months Ended March 31,
Revenue by Type of Customer	2018				2017
Industrial	$	100,100	22	%	$	87,614	23	%
Education		88,203	19	%		61,588	16	%
Office Buildings		69,120	15	%		52,434	14	%
Healthcare		63,183	14	%		51,767	14	%
Government		36,147	8	%		36,236	10	%
Retail, Restaurants and Entertainment		52,787	11	%		45,225	12	%
Multi-Family and Residential		33,052	7	%		26,870	7	%
Other		22,349	4	%		18,854	4	%
Total	$	464,941	100	%	$	380,588	100	%
	Three Months Ended March 31,
Revenue by Activity Type	2018				2017
New Construction	$	183,437	39	%	$	148,511	39	%
Existing Building Construction		155,197	33	%		118,266	31	%
Service Projects		40,175	9	%		42,609	11	%
Service Calls, Maintenance and Monitoring		86,132	19	%		71,202	19	%
Total	$	464,941	100	%	$	380,588	100	%

Schedule of contract assets and liabilities

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

	Contract		Contract
	Assets		Liabilities
Balance at beginning of period	$	30,116	$	106,005
Change due to acquisitions		546		2,227
Change due to conditional versus unconditional		411		—
Reclassified to unbilled accounts receivable		(28,980)		—
Change in timing for performance obligation to be satisfied		—		(293)
Balance at March 31, 2018	$	2,093	$	107,939