Comfort Systems USA (FIX) 10-Q 27 Jul 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 22, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Securities Act File Number	1-13011
Entity Registrant Name	COMFORT SYSTEMS USA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	76-0526487
Entity Address, Address Line One	675 Bering Drive
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77057
City Area Code	713
Local Phone Number	830-9600
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	FIX
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		35,776,204
Entity Central Index Key	0001035983
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 69,129	$ 58,776
Billed accounts receivable, less allowance for credit losses of $9,996 and $8,808, respectively	942,208	773,716
Unbilled accounts receivable, less allowance for credit losses of $751 and $715, respectively	79,767	61,881
Other receivables, less allowance for credit losses of $498 and $503, respectively	71,408	57,491
Inventories	31,246	21,853
Prepaid expenses and other	28,836	23,704
Costs and estimated earnings in excess of billings, less allowance for credit losses of $53 and $84, respectively	15,629	29,900
Total current assets	1,238,223	1,027,321
PROPERTY AND EQUIPMENT, NET	132,646	128,554
LEASE RIGHT-OF-USE ASSET	132,681	124,756
GOODWILL	611,000	592,114
IDENTIFIABLE INTANGIBLE ASSETS, NET	296,538	304,781
DEFERRED TAX ASSETS	16,594	22,905
OTHER NONCURRENT ASSETS	11,940	8,683
Total assets	2,439,622	2,209,114
CURRENT LIABILITIES:
Current maturities of long-term debt	2,448	2,788
Accounts payable	293,964	254,788
Accrued compensation and benefits	137,913	129,971
Billings in excess of costs and estimated earnings	386,258	307,380
Accrued self-insurance	20,967	22,227
Other current liabilities	126,630	119,400
Total current liabilities	968,180	836,554
LONG-TERM DEBT, NET	403,192	385,242
LEASE LIABILITIES	113,650	107,701
DEFERRED TAX LIABILITIES	1,745	1,745
OTHER LONG-TERM LIABILITIES	56,010	72,206
Total liabilities	1,542,777	1,403,448
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, $.01 par, 5,000,000 shares authorized, none issued and outstanding
Common stock, $.01 par, 102,969,912 shares authorized, 41,123,365 and 41,123,365 shares issued, respectively	411	411
Treasury stock, at cost, 5,342,665 and 5,032,311 shares, respectively	(183,024)	(150,580)
Additional paid-in capital	331,375	327,061
Retained earnings	748,083	628,774
Total stockholders' equity	896,845	805,666
Total liabilities and stockholders' equity	$ 2,439,622	$ 2,209,114

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CONSOLIDATED BALANCE SHEETS
Billed accounts receivable, allowance for credit losses (in dollars)	$ 9,996	$ 8,808
Unbilled accounts receivable, allowance for credit losses (in dollars)	751	715
Other receivables, allowance for credit losses (in dollars)	498	503
Costs and estimated earnings in excess of billings, allowance for credit losses (in dollars)	$ 53	$ 84
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	102,969,912	102,969,912
Common stock, shares issued	41,123,365	41,123,365
Treasury stock, shares	5,342,665	5,032,311

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUE	$ 1,017,948	$ 713,895	$ 1,903,164	$ 1,383,656
COST OF SERVICES	842,956	587,440	1,575,028	1,133,732
Gross profit	174,992	126,455	328,136	249,924
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	118,724	87,549	236,500	175,763
GAIN ON SALE OF ASSETS	(383)	(491)	(706)	(841)
Operating income	56,651	39,397	92,342	75,002
OTHER INCOME (EXPENSE):
Interest income	6	3	9	6
Interest expense	(3,026)	(1,360)	(5,155)	(2,857)
Changes in the fair value of contingent earn-out obligations	(115)	4,581	3,973	5,767
Other	(1)	161	55	92
Other income (expense)	(3,136)	3,385	(1,118)	3,008
INCOME BEFORE INCOME TAXES	53,515	42,782	91,224	78,010
PROVISION (BENEFIT) FOR INCOME TAXES	11,269	9,817	(37,784)	18,554
NET INCOME	$ 42,246	$ 32,965	$ 129,008	$ 59,456
INCOME PER SHARE:
Basic	$ 1.17	$ 0.91	$ 3.58	$ 1.64
Diluted	$ 1.17	$ 0.90	$ 3.57	$ 1.63
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic	35,970	36,403	36,022	36,345
Diluted	36,073	36,566	36,130	36,533

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Total
BALANCE at Dec. 31, 2020	$ 411	$ (129,243)	$ 322,451	$ 502,810	$ 696,429
BALANCE (in shares) at Dec. 31, 2020	41,123,365
BALANCE (in shares) at Dec. 31, 2020		(4,935,186)
Increase (Decrease) in Stockholders' Equity
Net income				26,491	26,491
Issuance of Stock:
Issuance of shares for options exercised		$ 1,616	(211)		1,405
Issuance of shares for options exercised (in shares)		61,454
Issuance of restricted stock & performance stock		$ 777	1,431		2,208
Issuance of restricted stock & performance stock (in shares)		29,544
Shares received in lieu of tax withholding payment on vested restricted stock		$ (854)			(854)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(11,424)
Stock-based compensation			2,472		2,472
Dividends				(4,163)	(4,163)
Share repurchase		$ (885)			(885)
Share repurchase (in shares)		(13,250)
BALANCE at Mar. 31, 2021	$ 411	$ (128,589)	326,143	525,138	723,103
BALANCE (in shares) at Mar. 31, 2021	41,123,365
BALANCE (in shares) at Mar. 31, 2021		(4,868,862)
BALANCE at Dec. 31, 2020	$ 411	$ (129,243)	322,451	502,810	696,429
BALANCE (in shares) at Dec. 31, 2020	41,123,365
BALANCE (in shares) at Dec. 31, 2020		(4,935,186)
Increase (Decrease) in Stockholders' Equity
Net income					59,456
BALANCE at Jun. 30, 2021	$ 411	$ (128,503)	326,179	553,925	752,012
BALANCE (in shares) at Jun. 30, 2021	41,123,365
BALANCE (in shares) at Jun. 30, 2021		(4,774,785)
BALANCE at Mar. 31, 2021	$ 411	$ (128,589)	326,143	525,138	723,103
BALANCE (in shares) at Mar. 31, 2021	41,123,365
BALANCE (in shares) at Mar. 31, 2021		(4,868,862)
Increase (Decrease) in Stockholders' Equity
Net income				32,965	32,965
Issuance of Stock:
Issuance of shares for options exercised		$ 1,853	191		2,044
Issuance of shares for options exercised (in shares)		69,342
Issuance of restricted stock & performance stock		$ 1,904	(1,904)
Issuance of restricted stock & performance stock (in shares)		71,816
Shares received in lieu of tax withholding payment on vested restricted stock		$ (1,509)			(1,509)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(19,989)
Stock-based compensation			1,749		1,749
Dividends				(4,178)	(4,178)
Share repurchase		$ (2,162)			(2,162)
Share repurchase (in shares)		(27,092)
BALANCE at Jun. 30, 2021	$ 411	$ (128,503)	326,179	553,925	752,012
BALANCE (in shares) at Jun. 30, 2021	41,123,365
BALANCE (in shares) at Jun. 30, 2021		(4,774,785)
BALANCE at Dec. 31, 2021	$ 411	$ (150,580)	327,061	628,774	$ 805,666
BALANCE (in shares) at Dec. 31, 2021	41,123,365				41,123,365
BALANCE (in shares) at Dec. 31, 2021		(5,032,311)			5,032,311
Increase (Decrease) in Stockholders' Equity
Net income				86,762	$ 86,762
Issuance of Stock:
Issuance of restricted stock & performance stock		$ 1,232	2,312		3,544
Issuance of restricted stock & performance stock (in shares)		38,863
Shares received in lieu of tax withholding payment on vested restricted stock		$ (1,399)			(1,399)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(15,348)
Stock-based compensation			2,605		2,605
Dividends				(4,673)	(4,673)
Share repurchase		$ (14,097)			(14,097)
Share repurchase (in shares)		(161,614)
BALANCE at Mar. 31, 2022	$ 411	$ (164,844)	331,978	710,863	878,408
BALANCE (in shares) at Mar. 31, 2022	41,123,365
BALANCE (in shares) at Mar. 31, 2022		(5,170,410)
BALANCE at Dec. 31, 2021	$ 411	$ (150,580)	327,061	628,774	$ 805,666
BALANCE (in shares) at Dec. 31, 2021	41,123,365				41,123,365
BALANCE (in shares) at Dec. 31, 2021		(5,032,311)			5,032,311
Increase (Decrease) in Stockholders' Equity
Net income					$ 129,008
BALANCE at Jun. 30, 2022	$ 411	$ (183,024)	331,375	748,083	$ 896,845
BALANCE (in shares) at Jun. 30, 2022	41,123,365				41,123,365
BALANCE (in shares) at Jun. 30, 2022		(5,342,665)			5,342,665
BALANCE at Mar. 31, 2022	$ 411	$ (164,844)	331,978	710,863	$ 878,408
BALANCE (in shares) at Mar. 31, 2022	41,123,365
BALANCE (in shares) at Mar. 31, 2022		(5,170,410)
Increase (Decrease) in Stockholders' Equity
Net income				42,246	42,246
Issuance of Stock:
Issuance of restricted stock & performance stock		$ 2,425	(2,425)
Issuance of restricted stock & performance stock (in shares)		75,092
Shares received in lieu of tax withholding payment on vested restricted stock		$ (1,848)			(1,848)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(20,658)
Stock-based compensation			1,822		1,822
Dividends				(5,026)	(5,026)
Share repurchase		$ (18,757)			(18,757)
Share repurchase (in shares)		(226,689)
BALANCE at Jun. 30, 2022	$ 411	$ (183,024)	$ 331,375	$ 748,083	$ 896,845
BALANCE (in shares) at Jun. 30, 2022	41,123,365				41,123,365
BALANCE (in shares) at Jun. 30, 2022		(5,342,665)			5,342,665

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Dividends (per share)	$ 0.14	$ 0.13	$ 0.115	$ 0.115

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 129,008	$ 59,456
Adjustments to reconcile net income to net cash provided by operating activities-
Amortization of identifiable intangible assets	25,158	17,749
Depreciation expense	16,295	13,925
Change in right-of-use assets	10,444	8,554
Bad debt expense (benefit)	1,116	(429)
Deferred tax provision	6,311	5,449
Amortization of debt financing costs	441	267
Gain on sale of assets	(706)	(841)
Changes in the fair value of contingent earn-out obligations	(3,973)	(5,767)
Stock-based compensation	6,430	6,860
(Increase) decrease in-
Receivables, net	(179,871)	(6,841)
Inventories	(9,432)	(5,365)
Prepaid expenses and other current assets	839	13,037
Costs and estimated earnings in excess of billings and unbilled accounts receivable	(1,184)	(2,752)
Other noncurrent assets	23	(1,105)
Increase (decrease) in-
Accounts payable and accrued liabilities	38,082	(10,964)
Billings in excess of costs and estimated earnings	77,718	27,510
Other long-term liabilities	(8,407)	(8,674)
Net cash provided by operating activities	108,292	110,069
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(20,215)	(10,762)
Proceeds from sales of property and equipment	1,559	1,530
Cash paid for acquisitions, net of cash acquired	(39,373)	(11,742)
Payments for investments	(1,236)
Net cash used in investing activities	(59,265)	(20,974)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving credit facility	485,000	25,000
Payments on revolving credit facility	(345,000)	(80,000)
Payments on term loan	(120,000)	(15,000)
Payments on other debt	(7,821)	(8,765)
Payments on finance lease liabilities	(899)
Debt financing costs	(2,297)
Payments of dividends to stockholders	(9,699)	(8,341)
Share repurchase	(32,854)	(3,047)
Shares received in lieu of tax withholding	(3,247)	(2,363)
Proceeds from exercise of options		3,449
Deferred acquisition payments	(50)	(400)
Payments for contingent consideration arrangements	(1,807)	(865)
Net cash used in financing activities	(38,674)	(90,332)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	10,353	(1,237)
CASH AND CASH EQUIVALENTS, beginning of period	58,776	54,896
CASH AND CASH EQUIVALENTS, end of period	$ 69,129	$ 53,659

Business and Organization

Business and Organization	6 Months Ended
	Jun. 30, 2022
Business and Organization
Business and Organization	1. Business and Organization ​ Comfort Systems USA, Inc., a Delaware corporation, provides comprehensive mechanical and electrical contracting services, which principally includes heating, ventilation and air conditioning (“HVAC”), plumbing, electrical, piping and controls, as well as off-site construction, monitoring and fire protection. We build, install, maintain, repair and replace mechanical, electrical and plumbing (“MEP”) systems throughout the United States. The terms “Comfort Systems,” “we,” “us,” or the “Company,” refer to Comfort Systems USA, Inc. or Comfort Systems USA, Inc. and its consolidated subsidiaries, as appropriate in the context. ​

Summary of Significant Accounti

Summary of Significant Accounting Policies and Estimates	6 Months Ended
	Jun. 30, 2022
Summary of Significant Accounting Policies and Estimates
Summary of Significant Accounting Policies and Estimates	2. Summary of Significant Accounting Policies and Estimates ​ Basis of Presentation ​ These interim statements should be read in conjunction with the historical Consolidated Financial Statements and related notes of Comfort Systems included in the Annual Report on Form 10-K as filed with the Securities and Exchange Commission (“SEC”) for the year ended December 31, 2021 (the “Form 10-K”). ​ The accompanying unaudited consolidated financial statements were prepared using generally accepted accounting principles for interim financial information and the instructions to Form 10-Q and applicable rules of Regulation S-X of the SEC. Accordingly, these financial statements do not include all the footnotes required by generally accepted accounting principles for complete financial statements and should be read in conjunction with the Form 10-K. We believe all adjustments necessary for a fair presentation of these interim statements have been included and are of a normal and recurring nature. The results of operations for interim periods are not necessarily indicative of the results for the full fiscal year. ​ Use of Estimates ​ The preparation of financial statements in conformity with generally accepted accounting principles requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, revenue and expenses and disclosures regarding contingent assets and liabilities. Actual results could differ from those estimates. The most significant estimates used in our financial statements affect revenue and cost recognition for construction contracts, self-insurance accruals, deferred tax assets, fair value accounting for acquisitions and the quantification of fair value for reporting units in connection with our goodwill impairment testing. ​ Recent Accounting Pronouncements ​ Recent Accounting Pronouncements Not Yet Adopted ​ In October 2021, the FASB issued ASU 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” This standard requires an acquirer to apply Accounting Standards Codification Topic 606 to recognize and measure contract assets and contract liabilities in a business combination. ASU 2021-08 is effective for fiscal years beginning after December 15, 2022 and interim periods within that year. Early adoption is permitted. We are currently evaluating the potential impact of this authoritative guidance on our consolidated financial statements. ​ Revenue Recognition ​ We recognize revenue over time for all of our services as we perform them because (i) control continuously transfers to that customer as work progresses, and (ii) we have the right to bill the customer as costs are incurred. The customer typically controls the work in process, as evidenced either by contractual termination clauses or by our rights to payment for work performed to date, plus a reasonable profit, for delivery of products or services that do not have an alternative use to the Company. ​ For the reasons listed above, revenue is recognized based on the extent of progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided. We generally use a cost-to-cost input method to measure our progress towards satisfaction of the performance obligation for our contracts, as it best depicts the transfer of assets to the customer that occurs as we incur costs on our contracts. Under the cost-to-cost input method, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenue, including estimated fees or profits, is recorded proportionally as costs are incurred. Costs to fulfill include labor, materials, subcontractors’ costs, other direct costs and an allocation of indirect costs. ​ For a small portion of our business in which our services are delivered in the form of service maintenance agreements for existing systems to be repaired and maintained, as opposed to constructed, our performance obligation is to maintain the customer’s mechanical system for a specific period of time. Similar to construction jobs, we recognize revenue over time; however, for service maintenance agreements in which the full cost to provide services may not be known, we generally use an input method to recognize revenue, which is based on the amount of time we have provided our services out of the total time we have been contracted to perform those services. Our revenue recognition policy is further discussed in Note 3 “Revenue from Contracts with Customers.” ​ Accounts Receivable and Allowance for Credit Losses ​ We are required to estimate and record the expected credit losses over the contractual life of our financial assets measured at amortized cost, including billed and unbilled accounts receivable, other receivables and contract assets. Accounts receivable include amounts from work completed in which we have billed or have an unconditional right to bill our customers. Our trade receivables are contractually due in less than a year. ​ We estimate our credit losses using a loss-rate method for each of our identified portfolio segments. Our portfolio segments are construction, service and other. While our construction and service financial assets are often with the same subset of customers and industries, our construction financial assets will generally have a lower loss-rate than service financial assets due to lien rights, which we are more likely to have on construction jobs. These lien rights result in lower credit loss expenses on average compared to receivables that do not have lien rights. Financial assets classified as Other include receivables that are not related to our core revenue producing activities, such as receivables related to our acquisition activity from former owners, our vendor rebate program or receivables for estimated losses in excess of our insurance deductible, which are accrued with a corresponding accrued insurance liability. ​ Loss rates for our portfolios are based on numerous factors, including our history of credit loss expense by portfolio, the financial strength of our customers and counterparties in each portfolio, the aging of our receivables, our expectation of likelihood of payment, macroeconomic trends in the U.S. and the current and forecasted non-residential construction market trends in the U.S. ​ In addition to the loss-rate calculations discussed above, we also record allowance for credit losses for specific receivables that are deemed to have a higher risk profile than the rest of the respective pool of receivables (e.g., when we hold concerns about a specific customer going bankrupt and no longer being able to pay the receivables due to us). ​ Income Taxes ​ We conduct business throughout the United States in virtually all fifty states. Our effective tax rate changes based upon our relative profitability, or lack thereof, in states with varying tax rates and rules. In addition, discrete items such as tax law changes, judgments and legal structures, can impact our effective tax rate. These items can also include the tax treatment for impairment of goodwill and other intangible assets, changes in fair value of acquisition-related assets and liabilities, uncertain tax positions, and accounting for losses associated with underperforming operations. ​ In early October 2020, we filed amended federal returns for 2016, 2017 and 2018, primarily to claim the credit for increasing research activities (the “R&D tax credit”) requesting refunds of $9.8 million, $9.5 million and $11.9 million, respectively. The $31.2 million of refunds requested was offset by unrecognized tax benefits of $28.8 million due to the uncertainty of the outcome of an Internal Revenue Service (“IRS”) examination. The R&D tax credit had no material impact on our effective tax rates for the 2020 and 2021 calendar years. ​ Following an IRS survey of previously filed refund claims for the 2016, 2017 and 2018 tax years, the Joint Committee on Taxation approved such refunds in late January 2022. As a result, our benefit for income taxes in the first quarter of 2022 included a $28.8 million reduction in unrecognized tax benefits plus approximately $1.6 million of net interest income on the refunds. ​ Our benefit for income taxes in the first quarter of 2022 was further increased by $26.8 million plus approximately $0.1 million of net interest income on the expected refunds due to our intention to claim the R&D tax credit for the 2019, 2020 and 2021 tax years. Additionally, we have included an estimate for the R&D tax credit in the computation of our annual effective tax rate for the current year and will continue to do so for the foreseeable future. ​ Financial Instruments ​ Our financial instruments consist of cash and cash equivalents, accounts receivable, other receivables, accounts payable and life insurance policies, for which we deem the carrying values approximate their fair value due to the short-term nature of these instruments, as well as notes to former owners and a revolving credit facility. We believe the carrying value of our debt associated with our revolving credit facility approximates its fair value due to the variable rate on such debt. ​ Investments ​ We have a $1.2 million investment with a fair value that is not readily determinable and is recorded at cost. This investment is included in “Other Noncurrent Assets” in our Consolidated Balance Sheet and is reviewed quarterly for impairment. We did not recognize any impairments in the current year related to this investment.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Jun. 30, 2022
Revenue from Contracts with Customers
Revenue from Contracts with Customers	3. Revenue from Contracts with Customers ​ Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. Sales-based taxes are excluded from revenue. ​ We provide mechanical and electrical contracting services. Our mechanical segment principally includes HVAC, plumbing, piping and controls, as well as off- site construction, monitoring and fire protection. Our electrical segment includes installation and servicing of electrical systems. We build, install, maintain, repair and replace products and systems throughout the United States. All of our revenue is recognized over time as we deliver goods and services to our customers. Revenue can be earned based on an agreed-upon fixed price or based on actual costs incurred, marked up at an agreed-upon percentage. ​ We account for a contract when: (i) it has approval and commitment from both parties, (ii) the rights of the parties are identified, (iii) payment terms are identified, (iv) the contract has commercial substance, and (v) collectability of consideration is probable. We consider the start of a project to be when the above criteria have been met and we either have written authorization from the customer to proceed or an executed contract. ​ We generally do not incur significant incremental costs related to obtaining or fulfilling a contract prior to the start of a project. On rare occasions, when significant pre-contract costs are incurred, they are capitalized and amortized over the life of the contract using a cost-to-cost input method to measure progress towards contract completion. We do not currently have any capitalized obtainment or fulfillment costs in our Consolidated Balance Sheet and have not incurred any impairment loss on such costs in the current year. ​ Due to the nature of the work required to be performed on many of our performance obligations, the estimation of total revenue and cost at completion (the process described below in more detail) is complex, subject to many variables and requires significant judgment. The consideration to which we are entitled on our long-term contracts may include both fixed and variable amounts. Variable amounts can either increase or decrease the transaction price. A common example of variable amounts that can either increase or decrease contract value are pending change orders that represent contract modifications for which a change in scope has been authorized or acknowledged by our customer, but the final adjustment to contract price is yet to be negotiated. Other examples of positive variable revenue include amounts awarded upon achievement of certain performance metrics, program milestones or cost of completion date targets and can be based upon customer discretion. Variable amounts can result in a deduction from contract revenue if we fail to meet stated performance requirements, such as complying with the construction schedule. ​ We include estimated amounts of variable consideration in the contract price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include estimated amounts in the contract price are based largely on an assessment of our anticipated performance and all information (historical, current and forecasted) that is reasonably available to us. We reassess the amount of variable consideration each accounting period until the uncertainty associated with the variable consideration is resolved. Changes in the assessed amount of variable consideration are accounted for prospectively as a cumulative adjustment to revenue recognized in the current period. ​ Contracts are often modified to account for changes in contract specifications and requirements. We consider contract modifications to exist when the modification either creates new, or changes the existing, enforceable rights and obligations. Most of our contract modifications are for goods or services that are not distinct from the existing performance obligation(s). The effect of a contract modification on the transaction price, and our measure of progress for the performance obligation to which it relates, is recognized as an adjustment to revenue (either as an increase or decrease) on a cumulative catch-up basis. ​ We have a Company-wide policy requiring periodic review of the Estimate at Completion in which management reviews the progress and execution of our performance obligations and estimated remaining obligations. As part of this process, management reviews information including, but not limited to, any outstanding key contract matters, progress towards completion and the related program schedule, identified risks and opportunities and the related changes in estimates of revenue and costs. The risks and opportunities include management's judgment about the ability and cost to achieve the schedule (e.g., the number and type of milestone events), technical requirements (e.g., a newly developed product versus a mature product) and other contract requirements. Management must make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the availability of materials, the length of time to complete the performance obligation (e.g., to estimate increases in wages and prices for materials and related support cost allocations), execution by our subcontractors, the availability and timing of funding from our customer, and overhead cost rates, among other variables. ​ Based on this analysis, any adjustments to revenue, cost of services, and the related impact to operating income are recognized as necessary in the quarter when they become known. These adjustments may result from positive program performance if we determine we will be successful in mitigating risks surrounding the technical, schedule and cost aspects of those performance obligations or realizing related opportunities and may result in an increase in operating income during the performance of individual performance obligations. Likewise, if we determine we will not be successful in mitigating these risks or realizing related opportunities, these adjustments may result in a decrease in operating income. Changes in estimates of revenue, cost of services and the related impact to operating income are recognized quarterly on a cumulative catch-up basis, meaning we recognize in the current period the cumulative effect of the changes on current and prior periods based on our progress towards complete satisfaction of a performance obligation ​ In the first six months of 2022 and 2021, net revenue recognized from our performance obligations satisfied in previous periods was not material. ​ Disaggregation of Revenue ​ Our consolidated 2022 revenue was derived from contracts to provide service activities in the mechanical and electrical services segments we serve. Refer to Note 11 “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. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Service Provided 2022 ​ 2021 ​ 2022 ​ 2021 ​ Mechanical Services ​ $ 776,757 76.3 % ​ $ 611,796 85.7 % ​ $ 1,459,268 76.7 % ​ $ 1,177,416 85.1 % Electrical Services ​ ​ 241,191 ​ 23.7 % ​ ​ 102,099 ​ 14.3 % ​ ​ 443,896 ​ 23.3 % ​ ​ 206,240 ​ 14.9 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Type of Customer ​ 2022 ​ ​ 2021 ​ 2022 ​ ​ 2021 Industrial ​ $ 470,491 ​ 46.2 % ​ $ 311,075 ​ 43.6 % ​ $ 880,675 ​ 46.3 % ​ $ 580,658 ​ 42.0 % Education ​ ​ 119,248 ​ 11.7 % ​ ​ 92,381 ​ 12.9 % ​ ​ 208,694 ​ 11.0 % ​ ​ 184,838 ​ 13.4 % Office Buildings ​ ​ 85,917 ​ 8.4 % ​ ​ 73,014 ​ 10.2 % ​ ​ 161,032 ​ 8.5 % ​ ​ 152,010 ​ 11.0 % Healthcare ​ ​ 141,113 ​ 13.9 % ​ ​ 96,004 ​ 13.4 % ​ ​ 275,908 ​ 14.5 % ​ ​ 191,095 ​ 13.8 % Government ​ ​ 66,212 ​ 6.5 % ​ ​ 42,506 ​ 6.0 % ​ ​ 123,677 ​ 6.5 % ​ ​ 85,671 ​ 6.2 % Retail, Restaurants and Entertainment ​ ​ 80,434 ​ 7.9 % ​ ​ 48,933 ​ 6.9 % ​ ​ 146,016 ​ 7.7 % ​ ​ 93,509 ​ 6.7 % Multi-Family and Residential ​ ​ 30,172 ​ 3.0 % ​ ​ 28,341 ​ 4.0 % ​ ​ 54,614 ​ 2.8 % ​ ​ 53,001 ​ 3.8 % Other ​ ​ 24,361 ​ 2.4 % ​ ​ 21,641 ​ 3.0 % ​ ​ 52,548 ​ 2.7 % ​ ​ 42,874 ​ 3.1 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Activity Type ​ 2022 ​ ​ 2021 ​ 2022 ​ ​ 2021 New Construction ​ $ 484,913 ​ 47.7 % ​ $ 329,890 ​ 46.2 % ​ $ 914,331 ​ 48.1 % ​ $ 631,951 ​ 45.7 % Existing Building Construction ​ ​ 304,316 ​ 29.9 % ​ ​ 215,317 ​ 30.2 % ​ ​ 563,601 ​ 29.6 % ​ ​ 431,918 ​ 31.2 % Service Projects ​ ​ 93,972 ​ 9.2 % ​ ​ 66,263 ​ 9.3 % ​ ​ 170,224 ​ 8.9 % ​ ​ 126,323 ​ 9.1 % Service Calls, Maintenance and Monitoring ​ ​ 134,747 ​ 13.2 % ​ ​ 102,425 ​ 14.3 % ​ ​ 255,008 ​ 13.4 % ​ ​ 193,464 ​ 14.0 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​ Contract Assets and Liabilities ​ ​ Contract liabilities consist of advance payments and billings in excess of revenue recognized. It is very unusual for us to have advanced payments with a term of greater than one year; therefore, our contract liabilities are usually all current. If we have advanced payments with a term greater than one year, the noncurrent portion of advanced payments would be included in “Other Long-term Liabilities” in our Consolidated Balance Sheets. Contract liabilities are not considered to have a significant financing component, as they are used to meet working capital requirements that are generally higher in the early stages of a contract and are intended to protect us from the other party failing to meet its obligations under the contract. Our contract assets and liabilities are reported in a net position on a contract by contract basis at the end of each reporting period. ​ The following table presents the changes in contract assets and contract liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ ​ Year Ended December 31, ​ 2022 ​ 2021 ​ Contract Contract ​ Contract Contract ​ Assets ​ Liabilities ​ Assets ​ Liabilities Balance at beginning of period $ 29,900 ​ $ 307,380 ​ $ 18,622 ​ $ 226,237 Change due to acquisitions / disposals ​ 2,426 ​ ​ 1,160 ​ ​ 10,356 ​ ​ 36,523 Change related to credit allowance ​ 31 ​ ​ — ​ ​ (5) ​ ​ — Other changes in the period ​ (16,728) ​ ​ 86,977 ​ ​ 927 ​ ​ 44,620 Balance at end of period $ 15,629 ​ $ 395,517 ​ $ 29,900 $ 307,380 ​ In the first six months of 2022 and 2021, we recognized revenue of $268.0 million and $195.0 million related to our contract liabilities at January 1, 2022 and January 1, 2021, respectively. ​ We did not have any impairment losses recognized on our receivables or contract assets in the first six months of 2022 and 2021. ​ Remaining Performance Obligations ​ Remaining construction performance obligations represent the remaining transaction price of firm orders for which work has not been performed and exclude unexercised contract options. As of June 30, 2022, the aggregate amount of the transaction price allocated to remaining performance obligations was , with the remaining recognized thereafter. Our service maintenance agreements are generally renewable agreements. We have adopted the practical expedient that allows us to not include service maintenance contracts with a total term of year or less; therefore, we do not report unfulfilled performance obligations for service maintenance agreements.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2022
Fair Value Measurements
Fair Value Measurements	4. Fair Value Measurements ​ Interest Rate Risk Management and Derivative Instruments We have interest rate swap agreements in place to reduce our exposure to variable interest rates on our revolving credit facility. The notional amount covered by these interest rate swaps was $80.0 million as of June 30, 2022, and the termination date is September 30, 2022. ​ We use derivative instruments to manage exposure to market risk, including interest rate risk. Unsettled amounts under our interest rate swaps are recorded in the Consolidated Balance Sheet at fair value in “Other Receivables” or “Other Current Liabilities.” Gains and losses on our interest rate swaps are recorded in the Consolidated Income Statement in “Interest Expense.” For the three months ended June 30, 2022 and June 30, 2021, we recognized a net gain of $0.1 million and a net loss of $0.1 million, respectively, related to our interest rate swaps. For the six months ended June 30, 2022 and June 30, 2021, we recognized a net loss of less than $0.1 million and $0.2 million, respectively, related to our interest rate swaps. We currently do not have any derivatives that are accounted for as hedges under ASC 815. ​ Fair Value Measurements ​ We classify and disclose assets and liabilities carried at fair value in one of the following three categories: ​ ● Level 1—quoted prices in active markets for identical assets and liabilities; ● Level 2—observable market-based inputs or unobservable inputs that are corroborated by market data; and ● Level 3—significant unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. ​ The following table summarizes the fair values, and levels within the fair value hierarchy in which the fair value measurements are included, for assets and liabilities measured on a recurring basis as of June 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at June 30, 2022 ​ Level 1 Level 2 Level 3 Total Cash and cash equivalents ​ $ 69,129 ​ $ — ​ $ — ​ $ 69,129 Life insurance—cash surrender value ​ $ — ​ $ 6,518 ​ $ — ​ $ 6,518 Contingent earn-out obligations ​ $ — ​ $ — ​ $ 26,676 ​ $ 26,676 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at December 31, 2021 ​ Level 1 Level 2 Level 3 Total Cash and cash equivalents ​ $ 58,776 ​ $ — ​ $ — ​ $ 58,776 Life insurance—cash surrender value ​ $ — ​ $ 6,643 ​ $ — ​ $ 6,643 Contingent earn-out obligations ​ $ — ​ $ — ​ $ 34,114 ​ $ 34,114 ​ Cash and cash equivalents consist primarily of highly rated money market funds at a variety of well-known institutions with original maturities of three months or less. The original cost of these assets approximates fair value due to their short-term maturity. The carrying value of our borrowings associated with the revolving credit facility approximate its fair value due to the variable rate on such debt. ​ We have life insurance policies covering 116 employees with a combined face value of $80.6 million. The policies are invested in several investment vehicles, and the fair value measurement of the cash surrender balance associated with these policies is determined using Level 2 inputs within the fair value hierarchy and will vary with investment performance. The cash surrender value of these policies was $6.5 million as of June 30, 2022 and $6.6 million as of December 31, 2021. These assets are included in “Other Noncurrent Assets” in our Consolidated Balance Sheets. ​ We value contingent earn-out obligations using a probability weighted discounted cash flow method. This fair value measurement is based on significant unobservable inputs in the market and thus represents a Level 3 measurement within the fair value hierarchy. This analysis reflects the contractual terms of the purchase agreements (e.g., minimum and maximum payments, length of earn-out periods, manner of calculating any amounts due, etc.) and utilizes assumptions with regard to future cash flows and operating income, probabilities of achieving such future cash flows and operating income and a weighted average cost of capital. Significant changes in any of these assumptions could result in a significantly higher or lower potential liability. The contingent earn-out obligations are measured at fair value each reporting period, and changes in estimates of fair value are recognized in earnings. As of June 30, 2022, cash flows were discounted using a weighted average cost of capital ranging from 11.0% - 17.0%. ​ The table below presents a reconciliation of the fair value of our contingent earn-out obligations that use significant unobservable inputs (Level 3) (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ Year Ended ​ ​ June 30, 2022 ​ December 31, 2021 ​ Balance at beginning of period $ 34,114 ​ $ 25,979 Issuances ​ — ​ 19,949 ​ Settlements ​ ​ (3,465) ​ ​ (3,994) ​ Adjustments to fair value ​ (3,973) ​ (7,820) ​ Balance at end of period ​ $ 26,676 ​ $ 34,114 ​ ​

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2022
Acquisitions
Acquisitions	5. Acquisitions ​ On April 1, 2022, we acquired Atlantic Electric, LLC and its related subsidiary (“Atlantic”), headquartered in Charleston, South Carolina, and with operations in South Carolina and Western North Carolina, for a total preliminary purchase price of $48.1 million, which included $34.1 million of cash paid on the closing date, $5.3 million in notes payable to former owners and a working capital adjustment. Atlantic performs electrical contracting for customers in various South Carolina markets, as well as installation of airport runway lighting in the Southeast. As a result of the acquisition, Atlantic is a wholly owned subsidiary of the Company reported in our electrical services segment. ​ On December 31, 2021, we acquired MEP Holding Co., Inc., and its related subsidiaries (collectively, “MEP Holdings”) for a total preliminary purchase price of $57.3 million, which included $45.2 million funded on the closing date, $7.6 million in notes payable to former owners, an earn-out that will be paid if certain financial targets are met after the acquisition date and a working capital adjustment. As a result of the acquisition, MEP Holdings is a wholly owned subsidiary of the Company and reports as a separate operating location in our electrical services segment. Additionally, on December 31, 2021, we completed an acquisition of a service and controls business in Kentucky with a total preliminary purchase price of $20.5 million and a temporary staffing company based in Indiana with a total preliminary purchase price of $4.7 million, which are both reported in our mechanical services segment. ​ On December 1, 2021, we acquired Ivey Mechanical Company, LLC (“Ivey”) headquartered in Kosciusko, Mississippi for a total preliminary purchase price of $79.1 million, which included $64.1 million of cash paid on the closing date, $8.0 million in notes payable to former owners, a $0.4 million short term payable plus an earn-out that will be paid if certain financial targets are met after the acquisition date and a working capital adjustment. As a result of the acquisition, Ivey is a wholly owned subsidiary of the Company and reports as a separate operating location in our mechanical services segment. ​ On August 1, 2021, we acquired all of the issued and outstanding equity interests of Amteck Holdco LLC and each of its wholly owned subsidiaries (collectively “Amteck”). The total purchase price was $138.9 million of which $113.1 million was allocated to goodwill and identifiable intangible assets. The total purchase price included $107.4 million in cash, $8.6 million in working capital adjustment, $10.0 million in notes payable to former owners and a $12.9 million contingent earn-out obligation. Amteck provides electrical contracting solutions and services, including design and build, pre-fabrication and installation for core electric and low-voltage systems, as well as services for planned maintenance, retrofit and emergency work. Amteck is headquartered in Kentucky and primarily serves the greater Southeastern United States, including Kentucky, Tennessee and the Carolinas. As a result of the acquisition, Amteck is a wholly owned subsidiary of the Company reported in our electrical services segment. ​ In the first quarter of 2021, we completed an acquisition of a mechanical contractor in Utah with a total purchase price of $18.1 million, which is reported in our mechanical services segment. ​ The results of operations of acquisitions are included in our consolidated financial statements from their respective acquisition dates. Our Consolidated Balance Sheet includes preliminary allocations of the purchase price to the assets acquired and liabilities assumed for the applicable acquisitions pending the completion of the final valuation of intangible assets and accrued liabilities. The acquisitions completed in the current and prior year were not material, individually or in the aggregate. Additional contingent purchase price (“earn-out”) has been or will be paid if certain acquisitions achieve predetermined profitability targets. Such earn-outs, when they are not subject to the continued employment of the sellers, are estimated as of the purchase date and included as part of the consideration paid for the acquisition. If we have an earn-out under which continued employment is a condition to receipt of payment, then the earn-out is recorded as compensation expense over the period earned.

Goodwill and Identifiable Intan

Goodwill and Identifiable Intangible Assets, Net	6 Months Ended
	Jun. 30, 2022
Goodwill and Identifiable Intangible Assets, Net
Goodwill and Identifiable Intangible Assets, Net	6. Goodwill and Identifiable Intangible Assets, Net ​ Goodwill ​ The changes in the carrying amount of goodwill are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mechanical Services ​ Electrical Services ​ ​ ​ ​ Segment Segment ​ Total Balance at December 31, 2020 ​ $ 307,448 ​ $ 156,944 ​ $ 464,392 ​ Acquisitions and purchase price adjustments (See Note 5) ​ 52,771 ​ ​ 74,951 ​ ​ 127,722 ​ Impact of segment reorganization ​ ​ 1,101 ​ ​ (1,101) ​ ​ — ​ Balance at December 31, 2021 ​ ​ 361,320 ​ ​ 230,794 ​ ​ 592,114 ​ Acquisitions and purchase price adjustments (See Note 5) ​ ​ 1,833 ​ ​ 17,053 ​ ​ 18,886 ​ Balance at June 30, 2022 ​ $ 363,153 ​ $ 247,847 ​ $ 611,000 ​ ​ During the fourth quarter of 2021, the Company performed a qualitative assessment for all of our reporting units except one for which we performed a quantitative assessment, which considered various factors, including changes in the carrying value of the reporting unit, forecasted operating results, long-term growth rates and discount rates. Additionally, we considered qualitative key events and circumstances (i.e. macroeconomic environment, industry and market specific conditions, cost factors and events specific to the reporting unit, etc.). Based on this assessment, we concluded that it was more likely than not that the fair value of each of the reporting units was substantially greater than its carrying value. Accordingly, no further testing was required. For our Texas electrical operation, we performed a step 1 quantitative assessment, and the calculated fair value exceeded the carrying value by 32%. As a result of the reporting unit’s smaller excess of fair value percentage, this reporting unit is more susceptible to impairment risk from additional adverse changes in its operating environment, including micro- and macroeconomic environment conditions that could negatively impact them. Such adverse changes could include worsening economic conditions in the locations or markets they primarily serve, whether due to COVID-19 or other events and conditions. As of June 30, 2022, the Texas electrical operation had a goodwill balance of $96.8 million. Identifiable Intangible Assets, Net ​ At June 30, 2022, future amortization expense of identifiable intangible assets is as follows (in thousands): ​ ​ ​ ​ ​ ​ Year ending December 31— ​ ​ 2022 (remainder of the year) $ 22,637 2023 ​ ​ 36,252 ​ 2024 ​ 34,063 ​ 2025 ​ 31,876 ​ 2026 ​ 31,032 ​ Thereafter ​ 140,678 ​ Total ​ $ 296,538 ​ ​

Debt Obligations

Debt Obligations	6 Months Ended
	Jun. 30, 2022
Debt Obligations
Debt Obligations	7. Debt Obligations ​ Debt obligations consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ 2022 2021 Revolving credit facility ​ $ 360,000 ​ $ 220,000 ​ Term loan ​ ​ — ​ ​ 120,000 ​ Notes to former owners ​ ​ 45,400 ​ 47,954 ​ Finance lease liabilities (See Note 8) ​ ​ — ​ ​ 266 ​ Other debt ​ ​ 240 ​ ​ — ​ Total principal amount ​ ​ 405,640 ​ 388,220 ​ Less—unamortized debt issuance costs ​ ​ — ​ ​ (190) ​ Total debt, net of unamortized debt issuance costs ​ ​ 405,640 ​ ​ 388,030 ​ Less—current portion ​ ​ (2,448) ​ (2,788) ​ Total long-term portion of debt, net ​ $ 403,192 ​ $ 385,242 ​ ​ At June 30, 2022, future principal payments of debt are as follows (in thousands): ​ ​ ​ ​ ​ ​ Year ending December 31— ​ ​ 2022 (remainder of the year) ​ $ 433 ​ 2023 ​ 9,467 2024 ​ 10,867 ​ 2025 ​ 22,229 ​ 2026 ​ 2,644 ​ 2027 ​ 360,000 ​ ​ ​ $ 405,640 ​ ​ ​ Revolving Credit Facility ​ On May 25, 2022, we amended our senior credit facility (as amended, the “Facility”) arranged by Wells Fargo Bank, National Association, as administrative agent, and provided by a syndicate of banks, increasing our borrowing capacity from $562.5 million (of which $450 million was a revolving credit facility) to $850 million. As amended, the Facility is composed of a revolving credit line guaranteed by certain of our subsidiaries, in the amount of $850.0 million, and the previous term loan has been eliminated. The amended Facility also provides for an accordion or increase option not to exceed the greater of (a) $250 million and (b) 1.0x Credit Facility Adjusted EBITDA (as defined below), as well as a sublimit of up to $175.0 million issuable in the form of letters of credit. The Facility expires in July 2027 and is secured by a first lien on substantially all of our personal property except for assets related to projects subject to surety bonds and the equity of, and assets held by, certain unrestricted subsidiaries and our wholly owned captive insurance company, and a second lien on our assets related to projects subject to surety bonds. In 2022, we incurred approximately $2.3 million in financing and professional costs in connection with the amendment to the Facility, which, combined with previously unamortized costs of $1.2 million, are being amortized on a straight-line basis as a non-cash charge to interest expense over the remaining term of the Facility. As of June 30, 2022, we had $360.0 million of outstanding borrowings on the revolving credit facility, $55.6 million in letters of credit outstanding and $434.4 million of credit available. ​ Covenants and Restrictions ​ The Facility contains financial covenants defining various financial measures and the levels of these measures with which we must comply. Covenant compliance is assessed as of each quarter end. Credit Facility Adjusted EBITDA is defined under the Facility for financial covenant purposes as consolidated net income for the four fiscal quarters ending as of any given quarterly covenant compliance measurement date, plus the corresponding amounts for (a) interest expense; (b) provision for income taxes; (c) depreciation and amortization; (d) stock or equity compensation; (e) other non-cash charges; and (f) pre-acquisition results of acquired companies. The Facility’s principal financial covenants include: ​ Net Leverage Ratio ​ Interest Coverage Ratio ​ Other Restrictions—The Facility (a) permits unlimited acquisitions when the Company’s Net Leverage Ratio is less than or equal to 3.25 to 1.00, (b) expands certain baskets for permitted indebtedness and liens, and (c) permits unlimited distributions, stock repurchases, and investments when the Net Leverage Ratio is less than or equal to 2.75 to 1.00. ​ While the Facility’s financial covenants do not specifically govern capacity under the Facility, if our debt level under the Facility at a quarter-end covenant compliance measurement date were to cause us to violate the Facility’s Net Leverage Ratio covenant, our borrowing capacity under the Facility and the favorable terms that we currently have could be negatively impacted. ​ We were in compliance with all of our financial covenants as of June 30, 2022. ​ Interest Rates and Fees ​ There are two interest rate options for borrowings under the Facility, the Base Rate Loan (as defined in the Facility) option and the Secured Overnight Financing Rate (“SOFR”) Loan option. Under the Base Rate Loan option, the interest rate is determined based on the highest of (a) the Federal Funds Rate (as defined in the Facility) plus 0.5%, (b) the prime lending rate established by Wells Fargo Bank, N.A., and (c) the one-month Adjusted Term SOFR (as defined in the Facility) plus 1.00%. Under the SOFR Loan option, the interest rate is determined based on Adjusted Term SOFR for a one, three, or six-month tenor at our election. Additional margins are then added to these two rates. The additional margins are determined based on our Net Leverage Ratio. ​ The interest rates under the Facility are floating rates determined by the broad financial markets, meaning they can and do move up and down from time to time. For illustrative purposes, the following are the respective market rates as of June 30, 2022 relating to interest options under the Facility: ​ ​ ​ ​ ​ Base Rate Loan Option: Federal Funds Rate plus 0.50% 2.08% ​ Wells Fargo Bank, N.A. Prime Rate ​ 4.75% ​ One-month SOFR plus 1.00% ​ 2.09% ​ SOFR Loan Option: ​ ​ ​ One-month SOFR ​ 1.09% ​ Six-month SOFR ​ 0.39% ​ ​ Certain of our vendors require letters of credit to ensure reimbursement for accounts they are disbursing on our behalf, such as to beneficiaries under our self-funded insurance programs. We have also occasionally used letters of credit to guarantee performance under our contracts and to ensure payment to our subcontractors and vendors under those contracts. Our lenders issue such letters of credit through the Facility. A letter of credit commits the lenders to pay specified amounts to the holder of the letter of credit if the holder demonstrates that we have failed to perform specified actions. If this were to occur, we would be required to reimburse the lenders for amounts they fund to honor the letter of credit holder’s claim. Absent a claim, there is no payment or reserving of funds by us in connection with a letter of credit. However, because a claim on a letter of credit would require immediate reimbursement by us to our lenders, letters of credit are treated as a use of Facility capacity. ​ Commitment fees are payable on the portion of the revolving loan capacity not in use for borrowings or letters of credit at any given time. Letter of credit fees and commitment fees are based on the Net Leverage Ratio. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Leverage Ratio ​ ​ Less than 1.00 1.00 to less than 1.75 1.75 to less than 2.50 2.50 to less than 3.00 3.00 or greater ​ Additional Per Annum Interest Margin Added Under: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Base Rate Loan Option ​ 0.00 % 0.25 % 0.50 % 0.75 % 1.00 % SOFR Loan Option ​ 1.00 % 1.25 % 1.50 % 1.75 % 2.00 % Letter of credit fees ​ 1.00 % 1.25 % 1.50 % 1.75 % 2.00 % Commitment fees on any portion of the Revolving Loan capacity not in use for borrowings or letters of credit at any given time ​ 0.15 % 0.175 % 0.20 % 0.225 % 0.25 % ​ The weighted average interest rate applicable to the borrowings under the revolving credit facility was approximately 2.8% as of June 30, 2022. ​ Notes to Former Owners ​ As part of the consideration used to acquire nine companies, we have outstanding notes to the former owners. Together, these notes had an outstanding balance of $45.4 million as of June 30, 2022. At June 30, 2022, future principal payments of notes to former owners by maturity year are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ Range of Stated ​ June 30, 2022 ​ Interest Rates 2022 $ 400 2.5 % 2023 ​ ​ 9,400 ​ 2.5 % 2024 ​ 10,800 ​ 2.5 - 3.0 % 2025 ​ 22,175 ​ 2.3 - 2.5 % 2026 ​ 2,625 ​ 2.5 % Total ​ $ 45,400 ​ ​ ​ ​ ​ F

Leases

Leases	6 Months Ended
	Jun. 30, 2022
Leases
Leases	8. Leases ​ We lease certain facilities, vehicles and equipment primarily under noncancelable operating leases. The most significant portion of these noncancelable operating leases are for the facilities occupied by our corporate office and our operating locations. We have finance leases on vehicles that are not material to our consolidated financial position. Leases with an initial term of 12 months or less are not recorded in the Balance Sheet. We do not separate lease components from their associated non-lease components pursuant to lease accounting guidance. We have certain leases with variable payments based on an index as well as some short-term leases on equipment and facilities. Variable lease expense and short-term lease expense were not material to our financial statements and aggregated to $8.1 million and $3.6 million in the first six months of 2022 and 2021, respectively. Lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we generally use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The weighted average discount rate for our operating leases as of June 30, 2022 and December 31, 2021 was 4.1% and 4.0%, respectively. We recognize operating lease expense, including escalating lease payments and lease incentives, on a straight-line basis over the lease term. Operating lease expense for the three months ended June 30, 2022 and 2021 was $10.8 million and $7.1 million, respectively. Operating lease expense for the six months ended June 30, 2022 and 2021 was $21.2 million and $14.4 million, respectively. ​ The lease terms generally range from three average remaining lease term for our operating leases was 8.2 years at June 30, 2022 and 8.7 years at December 31, 2021. ​ A majority of the Company’s real property leases are with individuals or entities with whom we have no other business relationship. However, in certain instances the Company enters into real property leases with current or former employees. Rent paid to related parties for the three months ended June 30, 2022 and 2021 was approximately $1.8 million and $1.3 million, respectively. Rent paid to related parties for the six months ended June 30, 2022 and 2021 was approximately $3.5 million and $2.5 million, respectively. ​ If we decide to cancel or terminate a lease before the end of its term, we would typically owe the lessor the remaining lease payments under the term of the lease. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. On rare occasions, we rent or sublease certain real estate assets that we no longer use to third parties. ​ Finance lease right-of-use assets are included in “Property and equipment, net,” and current and long-term finance lease liabilities are included within “Current maturities of long-term debt” and “Long-term debt, net,” respectively, in the Consolidated Balance Sheet. The following table summarizes the operating lease assets and liabilities included in the Consolidated Balance Sheet as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2022 ​ December 31, 2021 Operating lease right-of-use assets $ 132,681 ​ $ 124,756 Operating lease liabilities: ​ ​ ​ ​ ​ Other current liabilities $ 21,058 ​ $ 19,050 Long-term operating lease liabilities ​ 113,650 ​ ​ 107,701 Total operating lease liabilities $ 134,708 ​ $ 126,751 ​ The maturities of operating lease liabilities are as follows (in thousands): ​ ​ ​ ​ ​ Year ending December 31— ​ ​ ​ 2022 (excluding the six months ended June 30, 2022) ​ $ 13,357 2023 ​ ​ 24,687 2024 ​ ​ 22,013 2025 ​ ​ 20,987 2026 ​ ​ 17,980 Thereafter ​ ​ 60,273 Total Lease Payments ​ ​ 159,297 Less—Present Value Discount ​ ​ (24,589) Present Value of Operating Lease Liabilities ​ $ 134,708 ​ Supplemental information related to operating leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ 2022 ​ 2021 2022 ​ 2021 Cash paid for amounts included in the measurement of operating lease liabilities $ 6,702 ​ $ 5,347 ​ $ 13,016 ​ $ 10,700 Operating lease right-of-use assets obtained in exchange for lease liabilities $ 13,455 ​ $ 2,927 ​ $ 18,369 ​ $ 9,359 ​

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies
Commitments and Contingencies	9. Commitments and Contingencies ​ Claims and Lawsuits ​ We are subject to certain legal and regulatory claims, including lawsuits arising in the normal course of business. We maintain various insurance coverages to minimize financial risk associated with these claims. We have estimated and provided accruals for probable losses and related legal fees associated with certain litigation in the accompanying consolidated financial statements. While we cannot predict the outcome of these proceedings, in management’s opinion and based on reports of counsel, any liability arising from these matters individually and in the aggregate will not have a material effect on our operating results, cash flows or financial condition, after giving effect to provisions already recorded. ​ We are in a dispute with a customer regarding the outcome of a completed project and also regarding the obligation to perform subcontract work under two executed letters of intent for subsequent projects that we believe are not enforceable. The customer is claiming approximately $12 million in damages related to performance of the original project as well as excess costs to perform the work that was subject to the letters of intent. We are claiming approximately $9 million composed of unpaid amounts under the completed contract as well as costs and inefficiencies that we suffered. We have a lien on the project. Arbitration for this matter was completed in the second quarter of 2022, and we expect a decision in the third quarter of 2022. As of June 30, 2022, we recorded an accrual for this matter based on our analysis of likely outcomes related to this dispute; however, it is possible that the ultimate outcome and associated costs will deviate from our estimates and that, in the event of an unexpectedly adverse outcome, we may experience additional costs and expenses in future periods. Surety ​ Many customers, particularly in connection with new construction, require us to post performance and payment bonds issued by a financial institution known as a surety. If we fail to perform under the terms of a contract or to pay subcontractors and vendors who provided goods or services under a contract, the customer may demand that the surety make payments or provide services under the bond. We must reimburse the surety for any expenses or outlays it incurs. ​ Current market conditions for surety markets and bonding capacity are adequate, with acceptable terms and conditions. Historically, approximately 15% to 25% of our business has required bonds. While we currently have strong surety relationships to support our bonding needs, future market conditions or changes in the sureties’ assessment of our operating and financial risk could cause the sureties to decline to issue bonds for our work. If that were to occur, the alternatives include doing more business that does not require bonds, posting other forms of collateral for project performance, such as letters of credit or cash, and seeking bonding capacity from other sureties. We would likely also encounter concerns from customers, suppliers and other market participants as to our creditworthiness. While we believe our general operating and financial characteristics would enable us to ultimately respond effectively to an interruption in the availability of bonding capacity, such an interruption would likely cause our revenue and profits to decline in the near term. ​ Self-Insurance ​ We are substantially self-insured for workers’ compensation, employer’s liability, auto liability, general liability and employee group health claims, in view of the relatively high per-incident deductibles we absorb under our insurance arrangements for these risks. Losses are estimated and accrued based upon known facts, historical trends and industry averages. Estimated losses in excess of our deductible, which have not already been paid, are included in our accrual with a corresponding receivable from our insurance carrier. Loss estimates associated with the larger and longer-developing risks, such as workers’ compensation, auto liability and general liability, are reviewed by a third-party actuary quarterly. ​

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2022
Stockholders' Equity
Stockholders' Equity.	10. Stockholders’ Equity ​ Earnings Per Share ​ Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average number of shares of common stock outstanding during the year. Diluted EPS is computed considering the dilutive effect of stock options, restricted stock, restricted stock units and performance stock units. The vesting of unvested, contingently issuable performance stock units is based on the achievement of certain earnings per share targets and total shareholder return. These shares are considered contingently issuable shares for purposes of calculating diluted earnings per share. These shares are not included in the diluted earnings per share denominator until the performance criteria are met, if it is assumed that the end of the reporting period was the end of the contingency period. ​ Unvested restricted stock, restricted stock units and performance stock units are included in diluted earnings per share, weighted outstanding until the shares and units vest. Upon vesting, the vested restricted stock, restricted stock units and performance stock units are included in basic earnings per share weighted outstanding from the vesting date. ​ There were zero anti-dilutive stock options excluded from the calculation of diluted EPS for the three and six months ended June 30, 2022. There were less than 0.1 million anti-dilutive stock options excluded from the calculation of diluted EPS for the three and six months ended June 30, 2021. ​ The following table reconciles the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share for each of the periods presented (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 Common shares outstanding, end of period ​ 35,781 36,349 ​ 35,781 36,349 ​ Effect of using weighted average common shares outstanding ​ 189 54 ​ 241 (4) ​ Shares used in computing earnings per share—basic ​ 35,970 36,403 ​ 36,022 36,345 ​ Effect of shares issuable under stock option plans based on the treasury stock method ​ 42 97 ​ 42 114 ​ Effect of restricted and contingently issuable shares ​ 61 66 ​ 66 74 ​ Shares used in computing earnings per share—diluted ​ 36,073 36,566 ​ 36,130 36,533 ​ ​ Share Repurchase Program ​ On March 29, 2007, our Board of Directors (the “Board”) approved a stock repurchase program to acquire up to 1.0 million shares of our outstanding common stock. Subsequently, the Board has from time to time increased the number of shares that may be acquired under the program and approved extensions of the program. On May 17, 2022, the Board approved an extension to the program by increasing the shares authorized for repurchase by 0.7 million shares. Since the inception of the repurchase program, the Board has approved 10.9 million shares to be repurchased. As of June 30, 2022, we have repurchased a cumulative total of 10.1 million shares at an average price of $24.12 per share under the repurchase program. ​ The share repurchases will be made from time to time at our discretion in the open market or privately negotiated transactions as permitted by securities laws and other legal requirements, and subject to market conditions and other factors. The Board may modify, suspend, extend or terminate the program at any time. During the six months ended June 30, 2022, we repurchased 0.4 million shares for approximately $32.9 million at an average price of $84.61 per share.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2022
Segment Information
Segment Information	11. Segment Information Our activities are within the mechanical services industry and the electrical services industry, which represent our two reportable segments. We aggregate our operating segments into two reportable segments, as the operating segments meet all of the aggregation criteria. The following tables present information about our reportable segments (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2022 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 776,757 ​ $ 241,191 ​ $ — ​ $ 1,017,948 Gross Profit ​ $ 138,605 ​ $ 36,387 ​ $ — ​ $ 174,992 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 611,796 ​ $ 102,099 ​ $ — ​ $ 713,895 Gross Profit ​ $ 112,405 ​ $ 14,050 ​ $ — ​ $ 126,455 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 1,459,268 ​ $ 443,896 ​ $ — ​ $ 1,903,164 Gross Profit ​ $ 265,333 ​ $ 62,803 ​ $ — ​ $ 328,136 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 1,177,416 ​ $ 206,240 ​ $ — ​ $ 1,383,656 Gross Profit ​ $ 220,533 ​ $ 29,391 ​ $ — ​ $ 249,924 ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Estimates (Policies)	6 Months Ended
	Jun. 30, 2022
Summary of Significant Accounting Policies and Estimates
Basis of Presentation	Basis of Presentation ​ These interim statements should be read in conjunction with the historical Consolidated Financial Statements and related notes of Comfort Systems included in the Annual Report on Form 10-K as filed with the Securities and Exchange Commission (“SEC”) for the year ended December 31, 2021 (the “Form 10-K”). ​ The accompanying unaudited consolidated financial statements were prepared using generally accepted accounting principles for interim financial information and the instructions to Form 10-Q and applicable rules of Regulation S-X of the SEC. Accordingly, these financial statements do not include all the footnotes required by generally accepted accounting principles for complete financial statements and should be read in conjunction with the Form 10-K. We believe all adjustments necessary for a fair presentation of these interim statements have been included and are of a normal and recurring nature. The results of operations for interim periods are not necessarily indicative of the results for the full fiscal year.
Use of Estimates	Use of Estimates ​ The preparation of financial statements in conformity with generally accepted accounting principles requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, revenue and expenses and disclosures regarding contingent assets and liabilities. Actual results could differ from those estimates. The most significant estimates used in our financial statements affect revenue and cost recognition for construction contracts, self-insurance accruals, deferred tax assets, fair value accounting for acquisitions and the quantification of fair value for reporting units in connection with our goodwill impairment testing. ​
Recent Accounting Pronouncements	Recent Accounting Pronouncements ​ Recent Accounting Pronouncements Not Yet Adopted ​ In October 2021, the FASB issued ASU 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” This standard requires an acquirer to apply Accounting Standards Codification Topic 606 to recognize and measure contract assets and contract liabilities in a business combination. ASU 2021-08 is effective for fiscal years beginning after December 15, 2022 and interim periods within that year. Early adoption is permitted. We are currently evaluating the potential impact of this authoritative guidance on our consolidated financial statements. ​
Revenue Recognition	Revenue Recognition ​ We recognize revenue over time for all of our services as we perform them because (i) control continuously transfers to that customer as work progresses, and (ii) we have the right to bill the customer as costs are incurred. The customer typically controls the work in process, as evidenced either by contractual termination clauses or by our rights to payment for work performed to date, plus a reasonable profit, for delivery of products or services that do not have an alternative use to the Company. ​ For the reasons listed above, revenue is recognized based on the extent of progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided. We generally use a cost-to-cost input method to measure our progress towards satisfaction of the performance obligation for our contracts, as it best depicts the transfer of assets to the customer that occurs as we incur costs on our contracts. Under the cost-to-cost input method, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenue, including estimated fees or profits, is recorded proportionally as costs are incurred. Costs to fulfill include labor, materials, subcontractors’ costs, other direct costs and an allocation of indirect costs. ​ For a small portion of our business in which our services are delivered in the form of service maintenance agreements for existing systems to be repaired and maintained, as opposed to constructed, our performance obligation is to maintain the customer’s mechanical system for a specific period of time. Similar to construction jobs, we recognize revenue over time; however, for service maintenance agreements in which the full cost to provide services may not be known, we generally use an input method to recognize revenue, which is based on the amount of time we have provided our services out of the total time we have been contracted to perform those services. Our revenue recognition policy is further discussed in Note 3 “Revenue from Contracts with Customers.”
Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit Losses ​ We are required to estimate and record the expected credit losses over the contractual life of our financial assets measured at amortized cost, including billed and unbilled accounts receivable, other receivables and contract assets. Accounts receivable include amounts from work completed in which we have billed or have an unconditional right to bill our customers. Our trade receivables are contractually due in less than a year. ​ We estimate our credit losses using a loss-rate method for each of our identified portfolio segments. Our portfolio segments are construction, service and other. While our construction and service financial assets are often with the same subset of customers and industries, our construction financial assets will generally have a lower loss-rate than service financial assets due to lien rights, which we are more likely to have on construction jobs. These lien rights result in lower credit loss expenses on average compared to receivables that do not have lien rights. Financial assets classified as Other include receivables that are not related to our core revenue producing activities, such as receivables related to our acquisition activity from former owners, our vendor rebate program or receivables for estimated losses in excess of our insurance deductible, which are accrued with a corresponding accrued insurance liability. ​ Loss rates for our portfolios are based on numerous factors, including our history of credit loss expense by portfolio, the financial strength of our customers and counterparties in each portfolio, the aging of our receivables, our expectation of likelihood of payment, macroeconomic trends in the U.S. and the current and forecasted non-residential construction market trends in the U.S. ​ In addition to the loss-rate calculations discussed above, we also record allowance for credit losses for specific receivables that are deemed to have a higher risk profile than the rest of the respective pool of receivables (e.g., when we hold concerns about a specific customer going bankrupt and no longer being able to pay the receivables due to us).
Income Taxes	Income Taxes ​ We conduct business throughout the United States in virtually all fifty states. Our effective tax rate changes based upon our relative profitability, or lack thereof, in states with varying tax rates and rules. In addition, discrete items such as tax law changes, judgments and legal structures, can impact our effective tax rate. These items can also include the tax treatment for impairment of goodwill and other intangible assets, changes in fair value of acquisition-related assets and liabilities, uncertain tax positions, and accounting for losses associated with underperforming operations. ​ In early October 2020, we filed amended federal returns for 2016, 2017 and 2018, primarily to claim the credit for increasing research activities (the “R&D tax credit”) requesting refunds of $9.8 million, $9.5 million and $11.9 million, respectively. The $31.2 million of refunds requested was offset by unrecognized tax benefits of $28.8 million due to the uncertainty of the outcome of an Internal Revenue Service (“IRS”) examination. The R&D tax credit had no material impact on our effective tax rates for the 2020 and 2021 calendar years. ​ Following an IRS survey of previously filed refund claims for the 2016, 2017 and 2018 tax years, the Joint Committee on Taxation approved such refunds in late January 2022. As a result, our benefit for income taxes in the first quarter of 2022 included a $28.8 million reduction in unrecognized tax benefits plus approximately $1.6 million of net interest income on the refunds. ​ Our benefit for income taxes in the first quarter of 2022 was further increased by $26.8 million plus approximately $0.1 million of net interest income on the expected refunds due to our intention to claim the R&D tax credit for the 2019, 2020 and 2021 tax years. Additionally, we have included an estimate for the R&D tax credit in the computation of our annual effective tax rate for the current year and will continue to do so for the foreseeable future.
Financial Instruments	Financial Instruments ​ Our financial instruments consist of cash and cash equivalents, accounts receivable, other receivables, accounts payable and life insurance policies, for which we deem the carrying values approximate their fair value due to the short-term nature of these instruments, as well as notes to former owners and a revolving credit facility. We believe the carrying value of our debt associated with our revolving credit facility approximates its fair value due to the variable rate on such debt.
Investments	Investments ​ We have a $1.2 million investment with a fair value that is not readily determinable and is recorded at cost. This investment is included in “Other Noncurrent Assets” in our Consolidated Balance Sheet and is reviewed quarterly for impairment. We did not recognize any impairments in the current year related to this investment.
Leases	We lease certain facilities, vehicles and equipment primarily under noncancelable operating leases. The most significant portion of these noncancelable operating leases are for the facilities occupied by our corporate office and our operating locations. We have finance leases on vehicles that are not material to our consolidated financial position. Leases with an initial term of 12 months or less are not recorded in the Balance Sheet. We do not separate lease components from their associated non-lease components pursuant to lease accounting guidance. We have certain leases with variable payments based on an index as well as some short-term leases on equipment and facilities. Variable lease expense and short-term lease expense were not material to our financial statements and aggregated to $8.1 million and $3.6 million in the first six months of 2022 and 2021, respectively. Lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we generally use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The weighted average discount rate for our operating leases as of June 30, 2022 and December 31, 2021 was 4.1% and 4.0%, respectively. We recognize operating lease expense, including escalating lease payments and lease incentives, on a straight-line basis over the lease term. Operating lease expense for the three months ended June 30, 2022 and 2021 was $10.8 million and $7.1 million, respectively. Operating lease expense for the six months ended June 30, 2022 and 2021 was $21.2 million and $14.4 million, respectively. ​ The lease terms generally range from three average remaining lease term for our operating leases was 8.2 years at June 30, 2022 and 8.7 years at December 31, 2021. ​ A majority of the Company’s real property leases are with individuals or entities with whom we have no other business relationship. However, in certain instances the Company enters into real property leases with current or former employees. Rent paid to related parties for the three months ended June 30, 2022 and 2021 was approximately $1.8 million and $1.3 million, respectively. Rent paid to related parties for the six months ended June 30, 2022 and 2021 was approximately $3.5 million and $2.5 million, respectively. ​ If we decide to cancel or terminate a lease before the end of its term, we would typically owe the lessor the remaining lease payments under the term of the lease. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. On rare occasions, we rent or sublease certain real estate assets that we no longer use to third parties.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2022
Revenue from Contracts with Customers
Schedule of disaggregation of revenue	See details in the following tables (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Service Provided 2022 ​ 2021 ​ 2022 ​ 2021 ​ Mechanical Services ​ $ 776,757 76.3 % ​ $ 611,796 85.7 % ​ $ 1,459,268 76.7 % ​ $ 1,177,416 85.1 % Electrical Services ​ ​ 241,191 ​ 23.7 % ​ ​ 102,099 ​ 14.3 % ​ ​ 443,896 ​ 23.3 % ​ ​ 206,240 ​ 14.9 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Type of Customer ​ 2022 ​ ​ 2021 ​ 2022 ​ ​ 2021 Industrial ​ $ 470,491 ​ 46.2 % ​ $ 311,075 ​ 43.6 % ​ $ 880,675 ​ 46.3 % ​ $ 580,658 ​ 42.0 % Education ​ ​ 119,248 ​ 11.7 % ​ ​ 92,381 ​ 12.9 % ​ ​ 208,694 ​ 11.0 % ​ ​ 184,838 ​ 13.4 % Office Buildings ​ ​ 85,917 ​ 8.4 % ​ ​ 73,014 ​ 10.2 % ​ ​ 161,032 ​ 8.5 % ​ ​ 152,010 ​ 11.0 % Healthcare ​ ​ 141,113 ​ 13.9 % ​ ​ 96,004 ​ 13.4 % ​ ​ 275,908 ​ 14.5 % ​ ​ 191,095 ​ 13.8 % Government ​ ​ 66,212 ​ 6.5 % ​ ​ 42,506 ​ 6.0 % ​ ​ 123,677 ​ 6.5 % ​ ​ 85,671 ​ 6.2 % Retail, Restaurants and Entertainment ​ ​ 80,434 ​ 7.9 % ​ ​ 48,933 ​ 6.9 % ​ ​ 146,016 ​ 7.7 % ​ ​ 93,509 ​ 6.7 % Multi-Family and Residential ​ ​ 30,172 ​ 3.0 % ​ ​ 28,341 ​ 4.0 % ​ ​ 54,614 ​ 2.8 % ​ ​ 53,001 ​ 3.8 % Other ​ ​ 24,361 ​ 2.4 % ​ ​ 21,641 ​ 3.0 % ​ ​ 52,548 ​ 2.7 % ​ ​ 42,874 ​ 3.1 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ Six Months Ended June 30, Revenue by Activity Type ​ 2022 ​ ​ 2021 ​ 2022 ​ ​ 2021 New Construction ​ $ 484,913 ​ 47.7 % ​ $ 329,890 ​ 46.2 % ​ $ 914,331 ​ 48.1 % ​ $ 631,951 ​ 45.7 % Existing Building Construction ​ ​ 304,316 ​ 29.9 % ​ ​ 215,317 ​ 30.2 % ​ ​ 563,601 ​ 29.6 % ​ ​ 431,918 ​ 31.2 % Service Projects ​ ​ 93,972 ​ 9.2 % ​ ​ 66,263 ​ 9.3 % ​ ​ 170,224 ​ 8.9 % ​ ​ 126,323 ​ 9.1 % Service Calls, Maintenance and Monitoring ​ ​ 134,747 ​ 13.2 % ​ ​ 102,425 ​ 14.3 % ​ ​ 255,008 ​ 13.4 % ​ ​ 193,464 ​ 14.0 % Total ​ $ 1,017,948 ​ 100.0 % ​ $ 713,895 ​ 100.0 % ​ $ 1,903,164 ​ 100.0 % ​ $ 1,383,656 ​ 100.0 % ​
Schedule of contract assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ ​ Year Ended December 31, ​ 2022 ​ 2021 ​ Contract Contract ​ Contract Contract ​ Assets ​ Liabilities ​ Assets ​ Liabilities Balance at beginning of period $ 29,900 ​ $ 307,380 ​ $ 18,622 ​ $ 226,237 Change due to acquisitions / disposals ​ 2,426 ​ ​ 1,160 ​ ​ 10,356 ​ ​ 36,523 Change related to credit allowance ​ 31 ​ ​ — ​ ​ (5) ​ ​ — Other changes in the period ​ (16,728) ​ ​ 86,977 ​ ​ 927 ​ ​ 44,620 Balance at end of period $ 15,629 ​ $ 395,517 ​ $ 29,900 $ 307,380

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Measurements
Summary of fair values and levels within the fair value hierarchy in which the fair value measurements fall for assets and liabilities measured on a recurring basis	The following table summarizes the fair values, and levels within the fair value hierarchy in which the fair value measurements are included, for assets and liabilities measured on a recurring basis as of June 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at June 30, 2022 ​ Level 1 Level 2 Level 3 Total Cash and cash equivalents ​ $ 69,129 ​ $ — ​ $ — ​ $ 69,129 Life insurance—cash surrender value ​ $ — ​ $ 6,518 ​ $ — ​ $ 6,518 Contingent earn-out obligations ​ $ — ​ $ — ​ $ 26,676 ​ $ 26,676 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at December 31, 2021 ​ Level 1 Level 2 Level 3 Total Cash and cash equivalents ​ $ 58,776 ​ $ — ​ $ — ​ $ 58,776 Life insurance—cash surrender value ​ $ — ​ $ 6,643 ​ $ — ​ $ 6,643 Contingent earn-out obligations ​ $ — ​ $ — ​ $ 34,114 ​ $ 34,114 ​
Schedule of reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)	The table below presents a reconciliation of the fair value of our contingent earn-out obligations that use significant unobservable inputs (Level 3) (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ Year Ended ​ ​ June 30, 2022 ​ December 31, 2021 ​ Balance at beginning of period $ 34,114 ​ $ 25,979 Issuances ​ — ​ 19,949 ​ Settlements ​ ​ (3,465) ​ ​ (3,994) ​ Adjustments to fair value ​ (3,973) ​ (7,820) ​ Balance at end of period ​ $ 26,676 ​ $ 34,114 ​

Goodwill and Identifiable Int_2

Goodwill and Identifiable Intangible Assets, Net (Tables)	6 Months Ended
	Jun. 30, 2022
Goodwill and Identifiable Intangible Assets, Net
Schedule of changes in the carrying amount of goodwill	The changes in the carrying amount of goodwill are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mechanical Services ​ Electrical Services ​ ​ ​ ​ Segment Segment ​ Total Balance at December 31, 2020 ​ $ 307,448 ​ $ 156,944 ​ $ 464,392 ​ Acquisitions and purchase price adjustments (See Note 5) ​ 52,771 ​ ​ 74,951 ​ ​ 127,722 ​ Impact of segment reorganization ​ ​ 1,101 ​ ​ (1,101) ​ ​ — ​ Balance at December 31, 2021 ​ ​ 361,320 ​ ​ 230,794 ​ ​ 592,114 ​ Acquisitions and purchase price adjustments (See Note 5) ​ ​ 1,833 ​ ​ 17,053 ​ ​ 18,886 ​ Balance at June 30, 2022 ​ $ 363,153 ​ $ 247,847 ​ $ 611,000 ​
Schedule of future amortization expense of identifiable intangible assets	At June 30, 2022, future amortization expense of identifiable intangible assets is as follows (in thousands): ​ ​ ​ ​ ​ ​ Year ending December 31— ​ ​ 2022 (remainder of the year) $ 22,637 2023 ​ ​ 36,252 ​ 2024 ​ 34,063 ​ 2025 ​ 31,876 ​ 2026 ​ 31,032 ​ Thereafter ​ 140,678 ​ Total ​ $ 296,538 ​

Debt Obligations (Tables)

Debt Obligations (Tables)	6 Months Ended
	Jun. 30, 2022
Schedule of components of debt obligations	Debt obligations consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ 2022 2021 Revolving credit facility ​ $ 360,000 ​ $ 220,000 ​ Term loan ​ ​ — ​ ​ 120,000 ​ Notes to former owners ​ ​ 45,400 ​ 47,954 ​ Finance lease liabilities (See Note 8) ​ ​ — ​ ​ 266 ​ Other debt ​ ​ 240 ​ ​ — ​ Total principal amount ​ ​ 405,640 ​ 388,220 ​ Less—unamortized debt issuance costs ​ ​ — ​ ​ (190) ​ Total debt, net of unamortized debt issuance costs ​ ​ 405,640 ​ ​ 388,030 ​ Less—current portion ​ ​ (2,448) ​ (2,788) ​ Total long-term portion of debt, net ​ $ 403,192 ​ $ 385,242 ​
Schedule of future principal payments of notes to former owners	At June 30, 2022, future principal payments of debt are as follows (in thousands): ​ ​ ​ ​ ​ ​ Year ending December 31— ​ ​ 2022 (remainder of the year) ​ $ 433 ​ 2023 ​ 9,467 2024 ​ 10,867 ​ 2025 ​ 22,229 ​ 2026 ​ 2,644 ​ 2027 ​ 360,000 ​ ​ ​ $ 405,640 ​
Schedule of market rates relating to interest options under the Facility	​ ​ ​ ​ Base Rate Loan Option: Federal Funds Rate plus 0.50% 2.08% ​ Wells Fargo Bank, N.A. Prime Rate ​ 4.75% ​ One-month SOFR plus 1.00% ​ 2.09% ​ SOFR Loan Option: ​ ​ ​ One-month SOFR ​ 1.09% ​ Six-month SOFR ​ 0.39% ​
Summary of additional margins	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Leverage Ratio ​ ​ Less than 1.00 1.00 to less than 1.75 1.75 to less than 2.50 2.50 to less than 3.00 3.00 or greater ​ Additional Per Annum Interest Margin Added Under: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Base Rate Loan Option ​ 0.00 % 0.25 % 0.50 % 0.75 % 1.00 % SOFR Loan Option ​ 1.00 % 1.25 % 1.50 % 1.75 % 2.00 % Letter of credit fees ​ 1.00 % 1.25 % 1.50 % 1.75 % 2.00 % Commitment fees on any portion of the Revolving Loan capacity not in use for borrowings or letters of credit at any given time ​ 0.15 % 0.175 % 0.20 % 0.225 % 0.25 %
Notes to Former Owners
Schedule of future principal payments of notes to former owners	​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ Range of Stated ​ June 30, 2022 ​ Interest Rates 2022 $ 400 2.5 % 2023 ​ ​ 9,400 ​ 2.5 % 2024 ​ 10,800 ​ 2.5 - 3.0 % 2025 ​ 22,175 ​ 2.3 - 2.5 % 2026 ​ 2,625 ​ 2.5 % Total ​ $ 45,400 ​ ​ ​

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2022
Leases
Schedule of operating lease assets and liabilities	Finance lease right-of-use assets are included in “Property and equipment, net,” and current and long-term finance lease liabilities are included within “Current maturities of long-term debt” and “Long-term debt, net,” respectively, in the Consolidated Balance Sheet. The following table summarizes the operating lease assets and liabilities included in the Consolidated Balance Sheet as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2022 ​ December 31, 2021 Operating lease right-of-use assets $ 132,681 ​ $ 124,756 Operating lease liabilities: ​ ​ ​ ​ ​ Other current liabilities $ 21,058 ​ $ 19,050 Long-term operating lease liabilities ​ 113,650 ​ ​ 107,701 Total operating lease liabilities $ 134,708 ​ $ 126,751
Schedule of maturities of lease liabilities	The maturities of operating lease liabilities are as follows (in thousands): ​ ​ ​ ​ ​ Year ending December 31— ​ ​ ​ 2022 (excluding the six months ended June 30, 2022) ​ $ 13,357 2023 ​ ​ 24,687 2024 ​ ​ 22,013 2025 ​ ​ 20,987 2026 ​ ​ 17,980 Thereafter ​ ​ 60,273 Total Lease Payments ​ ​ 159,297 Less—Present Value Discount ​ ​ (24,589) Present Value of Operating Lease Liabilities ​ $ 134,708
Schedule of supplemental information related to leases	Supplemental information related to operating leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ 2022 ​ 2021 2022 ​ 2021 Cash paid for amounts included in the measurement of operating lease liabilities $ 6,702 ​ $ 5,347 ​ $ 13,016 ​ $ 10,700 Operating lease right-of-use assets obtained in exchange for lease liabilities $ 13,455 ​ $ 2,927 ​ $ 18,369 ​ $ 9,359

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2022
Stockholders' Equity
Reconciliation of number of shares outstanding with the number of shares used in computing basic and diluted earnings per share	The following table reconciles the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share for each of the periods presented (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 Common shares outstanding, end of period ​ 35,781 36,349 ​ 35,781 36,349 ​ Effect of using weighted average common shares outstanding ​ 189 54 ​ 241 (4) ​ Shares used in computing earnings per share—basic ​ 35,970 36,403 ​ 36,022 36,345 ​ Effect of shares issuable under stock option plans based on the treasury stock method ​ 42 97 ​ 42 114 ​ Effect of restricted and contingently issuable shares ​ 61 66 ​ 66 74 ​ Shares used in computing earnings per share—diluted ​ 36,073 36,566 ​ 36,130 36,533 ​ ​

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2022
Segment Information
Summary of information about reportable segments	The following tables present information about our reportable segments (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2022 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 776,757 ​ $ 241,191 ​ $ — ​ $ 1,017,948 Gross Profit ​ $ 138,605 ​ $ 36,387 ​ $ — ​ $ 174,992 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 611,796 ​ $ 102,099 ​ $ — ​ $ 713,895 Gross Profit ​ $ 112,405 ​ $ 14,050 ​ $ — ​ $ 126,455 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 1,459,268 ​ $ 443,896 ​ $ — ​ $ 1,903,164 Gross Profit ​ $ 265,333 ​ $ 62,803 ​ $ — ​ $ 328,136 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ Mechanical Services Electrical Services Corporate Consolidated Revenue ​ $ 1,177,416 ​ $ 206,240 ​ $ — ​ $ 1,383,656 Gross Profit ​ $ 220,533 ​ $ 29,391 ​ $ — ​ $ 249,924

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Estimates - Income Taxes (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Oct. 31, 2020	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Tax Examination [Line Items]
Reduced provision for income taxes			$ 28,800
Provision for income taxes		$ 11,269		$ 9,817	$ (37,784)	$ 18,554
Net interest income on the tax refunds			1,600
Investment fair value		$ 1,200			$ 1,200
Tax Year 2016 | R&D Tax Credit and 179D Deduction
Income Tax Examination [Line Items]
Provision for income taxes	$ 9,800
Tax Year 2017 | R&D Tax Credit and 179D Deduction
Income Tax Examination [Line Items]
Provision for income taxes	9,500
Tax Year 2018 | R&D Tax Credit and 179D Deduction
Income Tax Examination [Line Items]
Provision for income taxes	11,900
Total Tax Years 2016-2018
Income Tax Examination [Line Items]
Additions based on tax positions related to prior years	28,800
Total Tax Years 2016-2018 | R&D Tax Credit and 179D Deduction
Income Tax Examination [Line Items]
Provision for income taxes	$ 31,200
Total Tax Years 2019-2021
Income Tax Examination [Line Items]
R&D tax credits			26,800
Net interest income			$ 100

Revenue from Contracts with C_3

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%	100%	100%	100%
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%
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%	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%
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%	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%	4%	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%	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%
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%

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Contract Assets
Change due to acquisitions / disposals	$ 2,426		$ 10,356
Change related to credit allowance	31		(5)
Other changes in the period	(16,728)		927
Contract Liabilities
Change due to acquisitions / disposals	1,160		36,523
Other changes in the period	86,977		44,620
Contract assets:
Balance at beginning of period	29,900	$ 18,622	18,622
Balance at end of period	15,629		29,900
Costs and estimated earnings in excess of billings, less allowance for credit losses	15,629		29,900
Contract liabilities:
Balance at beginning of period	307,380	226,237	226,237
Balance at end of period	395,517		307,380
Total contract liabilities	395,517		$ 307,380
Revenue related to our contract liabilities	$ 268,000	$ 195,000

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)
Remaining Performance Obligations
The term of the renewable service maintenance agreements (in years)	1 year
Practical Expedient	true
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Remaining Performance Obligations
Remaining performance obligations	$ 2,810
Expected timing of performance obligations	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Minimum
Remaining Performance Obligations
Expected percentage of remaining performance obligations	80%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Maximum
Remaining Performance Obligations
Expected percentage of remaining performance obligations	85%

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) employee	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) employee	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Fair Value Measurements
Number of employees covered under life insurance policies | employee	116		116
Combined face value of life insurance policies	$ 80,600		$ 80,600
Cash surrender value	6,500		$ 6,500		$ 6,600
Minimum
Fair Value Measurements
Weighted average cost of capital			11%
Maximum
Fair Value Measurements
Weighted average cost of capital			17%
Contingent earn-out obligations
Reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)
Balance at beginning of period			$ 34,114	$ 25,979	25,979
Issuances					19,949
Settlements			(3,465)		(3,994)
Adjustments to fair value			(3,973)		(7,820)
Balance at end of period	26,676		26,676		34,114
Recurring basis | Total
Fair Value Measurements
Cash and cash equivalents	69,129		69,129		58,776
Life insurance-cash surrender value	6,518		6,518		6,643
Contingent earn-out obligations	26,676		26,676		34,114
Recurring basis | Quoted Market Prices In Active Markets for Identical Assets (Level 1)
Fair Value Measurements
Cash and cash equivalents	69,129		69,129		58,776
Recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Life insurance-cash surrender value	6,518		6,518		6,643
Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value Measurements
Contingent earn-out obligations	26,676		26,676		$ 34,114
Interest Rate Swap
Fair Value Measurements
Net gain (loss)	100	$ (100)	(100)	$ (200)
Interest Rate Swap | Not Designated as Hedging Instrument, Economic Hedge [Member]
Fair Value Measurements
Notional amount	$ 80,000		$ 80,000

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ in Thousands					3 Months Ended
	Apr. 01, 2022	Dec. 31, 2021	Dec. 01, 2021	Aug. 01, 2021	Mar. 31, 2021	Jun. 30, 2022	Dec. 31, 2020
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 592,114				$ 611,000	$ 464,392
Atlantic
Consideration transferred:
Fair value of consideration transferred	$ 48,100
Cash paid at closing	34,100
Notes issued to former owners	$ 5,300
MEP Holdings
Consideration transferred:
Fair value of consideration transferred		57,300
Cash paid at closing		45,200
Notes issued to former owners		7,600
Mechanical Contractor Kentucky
Consideration transferred:
Fair value of consideration transferred		20,500
Mechanical Contractor Indiana
Consideration transferred:
Fair value of consideration transferred		$ 4,700
Ivey
Consideration transferred:
Fair value of consideration transferred			$ 79,100
Cash paid at closing			64,100
Notes issued to former owners			8,000
Other amount payable			$ 400
Amteck
Consideration transferred:
Fair value of consideration transferred				$ 138,900
Cash paid at closing				107,400
Notes issued to former owners				10,000
Working capital adjustment				8,600
Estimated fair value of contingent earn-out payments				12,900
Identifiable intangible assets				$ 113,100
Mechanical Contractor Utah
Consideration transferred:
Fair value of consideration transferred					$ 18,100

Goodwill and Identifiable Int_3

Goodwill and Identifiable Intangible Assets, Net - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Changes in the carrying amount of goodwill
Balance at beginning of year	$ 592,114	$ 464,392
Acquisitions and purchase price adjustments (See Note 5)	18,886	127,722
Balance at end of period	611,000	592,114
Mechanical Services Segment
Changes in the carrying amount of goodwill
Balance at beginning of year	361,320	307,448
Acquisitions and purchase price adjustments (See Note 5)	1,833	52,771
Impact of segment reorganization		1,101
Balance at end of period	363,153	361,320
Electrical Services Industry
Changes in the carrying amount of goodwill
Balance at beginning of year	230,794	156,944
Acquisitions and purchase price adjustments (See Note 5)	17,053	74,951
Impact of segment reorganization		(1,101)
Balance at end of period	$ 247,847	$ 230,794

Goodwill and Identifiable Int_4

Goodwill and Identifiable Intangible Assets, Net - Identifiable Intangible Assets, Net (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Future amortization expense of identifiable intangible assets
2022 (remainder of the year)	$ 22,637
2023	36,252
2024	34,063
2025	31,876
2026	31,032
Thereafter	140,678
Total	$ 296,538

Goodwill and Identifiable Int_5

Goodwill and Identifiable Intangible Assets, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Jun. 30, 2022	Dec. 31, 2020
Goodwill
Goodwill	$ 592,114	$ 611,000	$ 464,392
Walker
Goodwill
Fair values in excess of carrying value (as a percent)	32%
Goodwill		$ 96,800

Debt Obligations (Details)

Debt Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Obligations
Finance lease liabilities (See Note 8)		$ 266
Other debt	$ 240
Total principal amount	405,640	388,220
Less-unamortized debt issuance costs		(190)
Total debt, net of unamortized debt issuance costs	405,640	388,030
Less-current portion	2,448	2,788
Total long-term portion of debt, net	403,192	385,242
Revolving credit facility
Debt Obligations
Total principal amount	360,000	220,000
Term loan
Debt Obligations
Total principal amount		120,000
Notes to Former Owners
Debt Obligations
Outstanding balance	$ 45,400	$ 47,954

Debt Obligations - Future Payme

Debt Obligations - Future Payments (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Future principal payments of long-term debt
2022 (remainder of the year)	$ 433
2023	9,467
2024	10,867
2025	22,229
2026	2,644
2027	360,000
Total debt	$ 405,640

Debt Obligations - Notes to For

Debt Obligations - Notes to Former Owners (Details) - Notes to Former Owners - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Future principal payments of long-term debt
Notes issued to former owners	$ 45,400	$ 47,954
2022
Future principal payments of long-term debt
Notes issued to former owners	$ 400
Stated interest rate (as a percent)	2.50%
2023
Future principal payments of long-term debt
Notes issued to former owners	$ 9,400
Stated interest rate (as a percent)	2.50%
2024
Future principal payments of long-term debt
Notes issued to former owners	$ 10,800
2024 | Minimum
Future principal payments of long-term debt
Stated interest rate (as a percent)	2.50%
2024 | Maximum
Future principal payments of long-term debt
Stated interest rate (as a percent)	3%
2025
Future principal payments of long-term debt
Notes issued to former owners	$ 22,175
2025 | Minimum
Future principal payments of long-term debt
Stated interest rate (as a percent)	2.30%
2025 | Maximum
Future principal payments of long-term debt
Stated interest rate (as a percent)	2.50%
2026
Future principal payments of long-term debt
Notes issued to former owners	$ 2,625
Stated interest rate (as a percent)	2.50%

Debt Obligations - Other (Detai

Debt Obligations - Other (Details)	6 Months Ended
	Jun. 30, 2022 USD ($) item	May 25, 2022 USD ($)	May 24, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Obligations
Financing and professional cost	$ 2,297,000
Revolving credit facility
Debt Obligations
Borrowing capacity		$ 850,000,000	$ 450,000,000
Outstanding borrowings	360,000,000
Letters of credit amount outstanding	55,600,000
Credit available	$ 434,400,000
Number of quarters of net earnings used for the calculation of the credit facility adjusted EBITDA | item	4
Principal financial covenants
Number of interest rate options | item	2
Number of quarters of Adjusted EBITDA and interest expense used for calculation of fixed charge coverage ratio | item	4
Other disclosures
Range of stated interest rates (as a percent)	2.80%
Revolving credit facility | Net Leverage Ratio, Less Than or Equal To 3.25
Principal financial covenants
Net leverage ratio used as basis for other restrictions	3.25
Revolving credit facility | Net Leverage Ratio, Less Than or Equal To 2.75
Principal financial covenants
Net leverage ratio used as basis for other restrictions	2.75
Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: Less than 1.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Letter of credit fees (as a percent)	1%
Commitment fees payable on unused portion of the facility (as a percent)	0.15%
Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.00 to 1.75
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Letter of credit fees (as a percent)	1.25%
Commitment fees payable on unused portion of the facility (as a percent)	0.175%
Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.75 to 2.50
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Letter of credit fees (as a percent)	1.50%
Commitment fees payable on unused portion of the facility (as a percent)	0.20%
Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 2.50 to 3.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Letter of credit fees (as a percent)	1.75%
Commitment fees payable on unused portion of the facility (as a percent)	0.225%
Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 3.00 or Greater
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Letter of credit fees (as a percent)	2%
Commitment fees payable on unused portion of the facility (as a percent)	0.25%
Revolving credit facility | Minimum
Principal financial covenants
Interest coverage ratio	3
Revolving credit facility | Maximum
Principal financial covenants
Maximum cash adjustment allowed in net leverage ratio calculation	$ 100,000,000
Leverage ratio	3.50
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: Less than 1.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	0%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.00 to 1.75
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	0.25%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.75 to 2.50
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	0.50%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 2.50 to 3.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	0.75%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 3.00 or Greater
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1%
Amended senior revolving credit facility
Debt Obligations
Borrowing capacity		850,000,000	562,500,000
Financing and professional cost	$ 2,300,000
Unamortized costs			$ 1,200,000
Amended senior revolving credit facility | Maximum
Debt Obligations
Line of credit borrowing capacity accordion option		$ 250,000,000
Notes to Former Owners
Other disclosures
Cumulative number of companies acquired | item	9
Outstanding balance	$ 45,400,000			$ 47,954,000
Letter of Credit
Debt Obligations
Borrowing capacity	$ 175,000,000
Federal Funds Rate | Revolving credit facility | Base rate
Market rates relating to interest options
Market rate (as a percent)	2.08%
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	0.50%
SOFR | Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: Less than 1.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1%
SOFR | Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.00 to 1.75
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1.25%
SOFR | Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.75 to 2.50
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1.50%
SOFR | Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 2.50 to 3.00
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1.75%
SOFR | Revolving credit facility | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 3.00 or Greater
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	2%
SOFR | Revolving credit facility | Base rate
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1%
Wells Fargo Bank, N.A. Prime Rate | Revolving credit facility | Base rate
Market rates relating to interest options
Market rate (as a percent)	4.75%
One-month SOFR | Revolving credit facility
Market rates relating to interest options
Market rate (as a percent)	1.09%
One-month SOFR | Revolving credit facility | Base rate
Market rates relating to interest options
Market rate (as a percent)	2.09%
Debt Instrument, Interest Rate, Effective Percentage [Abstract]
Additional per annum interest margin (as a percent)	1%
Six-month SOFR | Revolving credit facility
Market rates relating to interest options
Market rate (as a percent)	0.39%

Leases (Details)

Leases (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Option	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Finance lease liability					$ 266
Variable lease expense and short-term lease expenses			$ 8,100	$ 3,600
Weighted average discount rate for operating leases	4.10%		4.10%		4%
Operating lease expense	$ 10,800	$ 7,100	$ 21,200	14,400
Weighted average remaining lease term	8 years 2 months 12 days		8 years 2 months 12 days		8 years 8 months 12 days
Rent paid to related parties	$ 1,800	$ 1,300	$ 3,500	$ 2,500
Existence of option to extend			true
Minimum
Lessee, Lease, Description [Line Items]
Lease term for operating lease	3 years		3 years
Number of options to renew | Option			1
Maximum
Lessee, Lease, Description [Line Items]
Lease term for operating lease	10 years		10 years

Leases - Summary of Operating L

Leases - Summary of Operating Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Summary of lease asset and liabilities
Operating lease right-of-use assets	$ 132,681	$ 124,756
Operating lease liabilities:
Other current liabilities	$ 21,058	$ 19,050
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current	Other Liabilities, Current
Long-term operating lease liabilities	$ 113,650	$ 107,701
Total operating lease liabilities	$ 134,708	$ 126,751

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Maturities of lease liabilities:
2022 (excluding the six months ended June 30, 2022)	$ 13,357		$ 13,357
2023	24,687		24,687
2024	22,013		22,013
2025	20,987		20,987
2026	17,980		17,980
Thereafter	60,273		60,273
Total Lease Payments	159,297		159,297
Less-Present Value Discount	(24,589)		(24,589)
Present Value of Operating Lease Liabilities	134,708		134,708		$ 126,751
Supplemental information related to leases:
Cash paid for amounts included in the measurement of operating lease liabilities	6,702	$ 5,347	13,016	$ 10,700
Operating lease right-of-use assets obtained in exchange for lease liabilities	$ 13,455	$ 2,927	$ 18,369	$ 9,359

Commitments and Contingencies -

Commitments and Contingencies - Other and Bonds (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($) item
Obligation to perform subcontract work | Pending Litigation
Commitments and Contingencies
Letter of intent under dispute | item	2
Damages claimed	$ 9
Obligation to perform subcontract work | Customer | Pending Litigation
Commitments and Contingencies
Damages claimed	$ 12
Surety | Minimum
Surety
Percentage of business which has required bonds	15%
Surety | Maximum
Surety
Percentage of business which has required bonds	25%

Stockholders' Equity - Incentiv

Stockholders' Equity - Incentive and Other (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended		183 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	May 17, 2022	Mar. 29, 2007
Share Repurchase Program
Share repurchase			$ 32,854	$ 3,047
Anti-dilutive securities excluded from computation of earnings per share amount (in shares)	0	0.1	0	0.1
Stock Repurchase Program 2007
Share Repurchase Program
Number of shares of outstanding common stock authorized to be acquired under a stock repurchase program	10.9		10.9		10.9		1
Additional number of shares authorized for repurchase						0.7
Share repurchase (in shares)			0.4		10.1
Average price (in dollars per share)			$ 84.61		$ 24.12
Share repurchase			$ 32,900

Stockholders' Equity - Number o

Stockholders' Equity - Number of Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reconciliation of the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share
Common shares outstanding, end of period	35,781	36,349	35,781	36,349
Effect of using weighted average common shares outstanding	189	54	241	(4)
Shares used in computing earnings per share-basic	35,970	36,403	36,022	36,345
Effect of shares issuable under stock option plans based on the treasury stock method	42	97	42	114
Effect of restricted and contingently issuable shares	61	66	66	74
Shares used in computing earnings per share-diluted	36,073	36,566	36,130	36,533

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)
Segment Information
Number of reportable segments | segment			2
Revenue	$ 1,017,948	$ 713,895	$ 1,903,164	$ 1,383,656
Gross Profit	174,992	126,455	328,136	249,924
Operating | Mechanical Services Segment
Segment Information
Revenue	776,757	611,796	1,459,268	1,177,416
Gross Profit	138,605	112,405	265,333	220,533
Operating | Electrical Services Industry
Segment Information
Revenue	241,191	102,099	443,896	206,240
Gross Profit	$ 36,387	$ 14,050	$ 62,803	$ 29,391

N-2

N-2	6 Months Ended
	Jun. 30, 2022
Cover [Abstract]
Entity Central Index Key	0001035983
Amendment Flag	false
Securities Act File Number	1-13011
Document Type	10-Q
Entity Registrant Name	COMFORT SYSTEMS USA, INC.
Entity Address, Address Line One	675 Bering Drive
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77057
City Area Code	713
Local Phone Number	830-9600
Entity Emerging Growth Company	false