EMCOR (EME) 10-K28 Feb 242023 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2023	Feb. 22, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	1-8267
Entity Registrant Name	EMCOR Group, Inc.
Entity Incorporation, State or Country Code	DE
EIN	11-2125338
Entity Address, Address Line One	301 Merritt Seven
Entity Address, City or Town	Norwalk,
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06851-1092
City Area Code	(203)
Local Phone Number	849-7800
Title of 12(b) Security	Common Stock
Trading Symbol	EME
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business Flag	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 5,900,000,000
Entity Common Stock, Shares Outstanding		47,064,926
Entity Central Index Key	0000105634
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Stamford, Connecticut
Auditor Firm ID	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 789,750	$ 456,439
Accounts receivable, less allowance for credit losses of $22,502 and $22,382, respectively	3,203,490	2,567,371
Contract assets	269,885	273,176
Inventories	110,774	85,641
Prepaid expenses and other	73,072	79,346
Total current assets	4,446,971	3,461,973
Property, plant, and equipment, net	179,378	157,819
Operating lease right-of-use assets	310,498	268,063
Goodwill	956,549	919,151
Identifiable intangible assets, net	586,032	593,975
Other assets	130,293	123,626
Total assets	6,609,721	5,524,607
Current liabilities:
Current maturities of long-term debt and finance lease liabilities	2,465	15,567
Accounts payable	935,967	849,284
Contract liabilities	1,595,109	1,098,263
Accrued payroll and benefits	596,936	465,000
Other accrued expenses and liabilities	312,642	258,190
Operating lease liabilities, current	75,236	67,218
Total current liabilities	3,518,355	2,753,522
Long-term debt and finance lease liabilities	2,838	231,625
Operating lease liabilities, long-term	259,430	220,764
Other long-term obligations	358,283	344,405
Total liabilities	4,138,906	3,550,316
EMCOR Group, Inc. stockholders’ equity:
Preferred stock, $0.10 par value, 1,000,000 shares authorized, zero issued and outstanding	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized, 61,094,042 and 60,947,947 shares issued, respectively	611	609
Capital surplus	91,813	74,795
Accumulated other comprehensive loss	(85,704)	(93,451)
Retained earnings	3,814,439	3,214,281
Treasury stock, at cost 14,046,777 and 13,281,222 shares, respectively	(1,351,381)	(1,222,645)
Total EMCOR Group, Inc. stockholders’ equity	2,469,778	1,973,589
Noncontrolling interests	1,037	702
Total equity	2,470,815	1,974,291
Total liabilities and equity	$ 6,609,721	$ 5,524,607

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Allowance for credit losses (in US dollars)	$ 22,502	$ 22,382
Preferred stock, par value (in US dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in US dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares, issued	61,094,042	60,947,947
Treasury stock, shares	14,046,777	13,281,222

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenues	$ 12,582,873	$ 11,076,120	$ 9,903,580
Cost of sales	10,493,534	9,472,526	8,401,843
Gross profit	2,089,339	1,603,594	1,501,737
Selling, general and administrative expenses	1,211,233	1,038,717	970,937
Impairment loss on long-lived assets	2,350	0	0
Operating income	875,756	564,877	530,800
Net periodic pension (cost) income	(1,119)	4,311	3,625
Interest expense	(17,199)	(13,199)	(6,071)
Interest income	15,415	2,761	949
Income before income taxes	872,853	558,750	529,303
Income tax provision	239,524	152,628	145,602
Net income including noncontrolling interests	633,329	406,122	383,701
Net income attributable to noncontrolling interests	335	0	169
Net income attributable to EMCOR Group, Inc. (in US dollars)	$ 632,994	$ 406,122	$ 383,532
Basic earnings per common share (in US dollars per share)	$ 13.37	$ 8.13	$ 7.09
Diluted earnings per common share (in US dollars per share)	13.31	8.10	7.06
Dividends declared per common share (in US dollars per share)	$ 0.69	$ 0.54	$ 0.52

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income including noncontrolling interests		$ 633,329	$ 406,122	$ 383,701
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments		6,417	(10,786)	(360)
Changes in post retirement plans	[1]	1,330	897	26,031
Other comprehensive income (loss)		7,747	(9,889)	25,671
Comprehensive income		641,076	396,233	409,372
Comprehensive income attributable to noncontrolling interests		335	0	169
Comprehensive income attributable to EMCOR Group, Inc.		$ 640,741	$ 396,233	$ 409,203

[1]Net of tax provision of $0.5 million, $0.3 million, and $8.7 million for the years ended December 31, 2023, 2022, and 2021, respectively.

Consolidated Statements Of Co_2

Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Post retirement plans, tax (expense) benefit	$ (0.5)	$ (0.3)	$ (8.7)

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows - operating activities:
Net income including noncontrolling interests		$ 633,329	$ 406,122	$ 383,701
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		51,822	47,296	48,347
Amortization of identifiable intangible assets		67,143	61,315	64,089
Provision for credit losses		7,859	5,166	8,041
Deferred income taxes		(16,651)	10,483	9,517
Gain on sale or disposal of property, plant, and equipment		(2,057)	(6,393)	(782)
Excess tax benefits from share-based compensation		(1,719)	(1,654)	(828)
Equity (income) loss from unconsolidated entities		(1,660)	(391)	1,170
Non-cash expense for amortization of debt issuance costs		960	960	960
Non-cash expense from contingent consideration arrangements		2,287	1,610	1,810
Non-cash expense for impairment of long-lived assets		2,350	0	0
Non-cash share-based compensation expense		13,739	12,125	11,107
Distributions from unconsolidated entities		400	400	44
Changes in operating assets and liabilities, excluding the effect of businesses acquired:
Increase in accounts receivable		(626,494)	(340,091)	(246,856)
Increase in inventories		(23,442)	(31,541)	(116)
Decrease (increase) in contract assets		5,733	(44,725)	(50,648)
Increase in accounts payable		82,192	111,488	54,849
Increase in contract liabilities		489,728	299,897	44,713
Increase (decrease) in accrued payroll and benefits and other accrued expenses and liabilities		189,268	(30,025)	46,573
Changes in other assets and liabilities, net		24,868	(4,109)	(56,874)
Net cash provided by operating activities		899,655	497,933	318,817
Cash flows - investing activities:
Payments for acquisitions of businesses, net of cash acquired		(96,491)	(98,656)	(118,239)
Proceeds from sale or disposal of property, plant, and equipment		13,604	7,145	2,754
Purchases of property, plant, and equipment		(78,404)	(49,289)	(36,192)
Investments in and advances to unconsolidated entities		0	0	(1,595)
Distributions from unconsolidated entities		0	0	196
Net cash used in investing activities		(161,291)	(140,800)	(153,076)
Cash flows - financing activities:
Proceeds from revolving credit facility		200,000	270,000	0
Repayments of revolving credit facility		(200,000)	(270,000)	0
Repayments of long-term debt and debt issuance costs		(246,171)	(13,875)	(13,875)
Repayments of finance lease liabilities		(2,776)	(3,551)	(4,189)
Dividends paid to stockholders		(32,684)	(27,187)	(28,163)
Repurchases of common stock		(127,713)	(660,609)	(195,546)
Taxes paid related to net share settlements of equity awards		(6,060)	(7,539)	(4,210)
Issuances of common stock under employee stock purchase plan		9,189	8,177	7,328
Payments for contingent consideration arrangements		(5,839)	(5,534)	(6,758)
Distributions to noncontrolling interests		0	0	(43)
Net cash used in financing activities		(412,054)	(710,118)	(245,456)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		6,372	(12,515)	(1,279)
Increase (decrease) in cash, cash equivalents, and restricted cash		332,682	(365,500)	(80,994)
Cash, cash equivalents, and restricted cash at beginning of year (1)	[1]	457,068	822,568	903,562
Cash, cash equivalents, and restricted cash at end of period (1)	[1]	$ 789,750	$ 457,068	$ 822,568

[1] Includes $0.6 million, $1.2 million, and $0.7 million of restricted cash classified as “Prepaid expenses and other” in the Consolidated Balance Sheets as of December 31, 2022, 2021, and 2020, respectively.

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Cash Flows [Abstract]
Restricted cash	$ 0.6	$ 1.2	$ 0.7

Consolidated Statements Of Equi

Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus	Accumulated Other Comprehensive Loss	[1]	Retained Earnings	Treasury stock	Noncontrolling Interests
Balance at Dec. 31, 2020	$ 2,053,244	$ 606	$ 47,464	$ (109,233)		$ 2,480,321	$ (366,490)	$ 576
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income including noncontrolling interests	383,701					383,532		169
Other comprehensive income (loss)	25,671			25,671
Common stock issued under share-based compensation plans	0	1	(1)
Tax withholding for common stock issued under share-based compensation plans	(4,210)		(4,210)
Common stock issued under employee stock purchase plan	7,328		7,328
Common stock dividends	(28,163)					(28,349)
Common stock dividends, accrued dividend shares			186
Repurchases of common stock	(195,546)						(195,546)
Distributions to noncontrolling interests	(43)							(43)
Share-based compensation expense	11,107		11,107
Balance at Dec. 31, 2021	2,253,089	607	61,874	(83,562)		2,835,504	(562,036)	702
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income including noncontrolling interests	406,122					406,122
Other comprehensive income (loss)	(9,889)			(9,889)
Common stock issued under share-based compensation plans	2	2
Tax withholding for common stock issued under share-based compensation plans	(7,539)		(7,539)
Common stock issued under employee stock purchase plan	8,177		8,177
Common stock dividends	(27,187)					(27,345)
Common stock dividends, accrued dividend shares			158
Repurchases of common stock	(660,609)						(660,609)
Share-based compensation expense	12,125		12,125
Balance at Dec. 31, 2022	1,974,291	609	74,795	(93,451)		3,214,281	(1,222,645)	702
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income including noncontrolling interests	633,329					632,994		335
Other comprehensive income (loss)	7,747			7,747
Common stock issued under share-based compensation plans	0	2	(2)
Tax withholding for common stock issued under share-based compensation plans	(6,060)		(6,060)
Common stock issued under employee stock purchase plan	9,189		9,189
Common stock dividends	(32,684)					(32,836)
Common stock dividends, accrued dividend shares			152
Repurchases of common stock	(128,736)						(128,736)
Share-based compensation expense	13,739		13,739
Balance at Dec. 31, 2023	$ 2,470,815	$ 611	$ 91,813	$ (85,704)		$ 3,814,439	$ (1,351,381)	$ 1,037

[1] Represents cumulative foreign currency translation and post retirement liability adjustments of $(1.8) million and $(83.9) million, respectively, as of December 31, 2023, $(8.3) million and $(85.2) million, respectively, as of December 31, 2022, and $2.5 million and $(86.1) million, respectively, as of December 31, 2021.

Consolidated Statements Of Eq_2

Consolidated Statements Of Equity (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cumulative post retirement liability adjustment	$ (83.9)	$ (85.2)	$ (86.1)
Cumulative foreign currency translation adjustment	$ (1.8)	$ (8.3)	$ 2.5

Nature of Operations

Nature of Operations	12 Months Ended
Nature of Operations	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	NATURE OF OPERATIONS References to the “Company,” “EMCOR,” “we,” “us,” “our” and similar words refer to EMCOR Group, Inc. and its consolidated subsidiaries unless the context indicates otherwise.

Summary of Significant Accounti

Summary of Significant Accounting Policies (Notes)	12 Months Ended
Summary of Significant Accounting Policies (Notes)	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation The consolidated financial statements include the accounts of the Company and the subsidiaries and joint ventures it controls. All intercompany accounts and transactions have been eliminated. Investments over which we exercise significant influence, but do not control, are accounted for using the equity method of accounting. For joint ventures that have been accounted for using the consolidation method of accounting, noncontrolling interests represent the allocation of earnings to our joint venture partners who either have a minority-ownership interest in the joint venture or are not the primary beneficiary of the joint venture. The results of operations of companies acquired have been included in the results of operations from the date of the respective acquisition. Principles of Preparation The preparation of the consolidated financial statements, in conformity with accounting principles generally accepted in the United States, requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could materially differ from those estimates. Our reportable segments and related disclosures reflect certain reclassifications of prior year amounts from our United States mechanical construction and facilities services segment to our United States building services segment due to changes in our internal reporting structure aimed at realigning our service offerings. Revenue Recognition Revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. Refer to Note 3 - Revenue from Contracts with Customers of the notes to consolidated financial statements for additional information. Cash and Cash Equivalents For purposes of the consolidated financial statements, we consider all highly liquid instruments with original maturities of three months or less to be cash equivalents. We maintain a centralized cash management system whereby our excess cash balances are invested in high quality short-term money market instruments, which are considered cash equivalents. We have cash balances in certain of our domestic bank accounts that exceed federally insured limits. Accounts Receivable and Allowance for Credit Losses Accounts receivable are recognized in the period we deliver goods and services to our customers or when our right to consideration is unconditional. The Company maintains an allowance for credit losses to reduce outstanding receivables to their net realizable value. Judgment is required when determining expected credit losses. Estimates of such losses are recorded when we believe a customer, or group of customers, may not be able to meet their financial obligations due to deterioration in financial condition or credit rating. Factors relevant to our assessment include our prior collection history with our customers, the related aging of past due balances, projections of credit losses based on historical trends in credit quality indicators or past events, and forecasts of future economic conditions. In addition to monitoring delinquent accounts, management reviews the credit quality of its receivables by, among other things, obtaining credit ratings of significant customers, assessing economic and market conditions, and evaluating material changes to a customer’s business, cash flows, and financial condition. NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Continued) At December 31, 2023 and 2022, our accounts receivable of $3,203.5 million and $2,567.4 million, respectively, were recorded net of allowances for credit losses of $22.5 million and $22.4 million, respectively. Allowances for credit losses are based on the best facts available and are reassessed and adjusted on a regular basis as additional information is received. Should anticipated collections fail to materialize, or if future economic conditions compare unfavorably to our forecasts, we could experience an increase in our credit losses. The provision for credit losses during 2023, 2022, and 2021 amounted to approximately $7.9 million, $5.2 million, and $8.0 million, respectively. The change in the allowance for credit losses for the year ended December 31, 2023 was as follows (in thousands): Balance at December 31, 2022 $ 22,382 Provision for credit losses 7,859 Amounts written off against the allowance, net of recoveries (7,739) Balance at December 31, 2023 $ 22,502 Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined principally using the average cost method. Refer to Note 6 - Inventories of the notes to consolidated financial statements for additional information. Leases At the inception of a contract, we determine whether the arrangement is or contains a lease. Leases are classified as either operating or finance, based on our evaluation of certain criteria. With the exception of short-term leases (leases with an initial term of 12 months or less), we record right-of-use assets and corresponding lease liabilities on the Consolidated Balance Sheets for all leases with contractual fixed payments. Lease liabilities are measured at the present value of remaining lease payments, while right-of-use assets are initially set equal to the lease liability, as adjusted for any payments made prior to lease commencement, lease incentives, and any initial direct costs incurred by us. For operating leases, rent expense is recognized on a straight-line basis over the term of the lease, and right-of-use assets are subsequently re-measured to reflect the effect of uneven lease payments. For finance leases, right-of-use assets are amortized on a straight-line basis over the shorter of the lease term or the useful life of the underlying asset. Expenses for finance leases include the amortization of right-of-use assets, which is recorded as depreciation and amortization expense, and interest expense, which reflects interest accrued on the lease liability. Short-term leases are not recorded on the Consolidated Balance Sheets but are expensed on a straight-line basis over the lease term. The majority of the Company’s short-term leases relate to equipment used on construction projects. Such equipment leases are considered short-term in nature unless it is reasonably certain that the equipment will be leased for a period greater than 12 months. Refer to Note 16 - Leases of the notes to consolidated financial statements for additional information. Property, Plant, and Equipment Property, plant, and equipment is stated at cost. Depreciation, including amortization of assets under finance leases, is recorded using the straight-line method over estimated useful lives of 3 to 10 years for machinery and equipment, 3 to 7 years for vehicles, furniture and fixtures, and computer hardware/software, and 25 years for buildings. Leasehold improvements are amortized over the shorter of the remaining lease term or the expected useful life of the improvement. The carrying values of property, plant, and equipment are reviewed for impairment whenever facts and circumstances indicate that the carrying amount may not be fully recoverable. In performing this review for recoverability, property, plant, and equipment is assessed for possible impairment by comparing their carrying values to the undiscounted net pre-tax cash flows expected to result from the use of the asset. Impaired assets are written down to their fair values, generally determined based on their estimated future discounted cash flows. NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Continued) Goodwill, Identifiable Intangible Assets, and Other Long-Lived Assets Goodwill and indefinite-lived intangible assets, such as trade names, are evaluated at least annually for impairment (each October 1, absent any earlier identified impairment indicators) and are written down if impaired. Identifiable intangible assets with finite lives are amortized over their useful lives and, along with certain other long-lived assets, are reviewed for impairment whenever facts and circumstances indicate that their carrying values may not be fully recoverable. See Note 8 - Goodwill, Identifiable Intangible Assets, and Other Long-Lived Assets of the notes to consolidated financial statements for additional information. Insurance Liabilities We have loss payment deductibles for certain workers’ compensation, automobile liability, general liability, and property claims, have self-insured retentions for certain other casualty claims, and are self-insured for employee-related healthcare claims. In addition, we maintain a wholly-owned captive insurance subsidiary to manage certain of our insurance liabilities. Losses are recorded based upon estimates of our liability for claims incurred and for claims incurred but not reported. The liabilities are derived from known facts, historical trends, and industry averages, utilizing the assistance of an independent third-party actuary to determine the best estimate for the majority of these obligations. As of December 31, 2023 and 2022, the estimated current portion of such undiscounted insurance liabilities, included in “Other accrued expenses and liabilities” in the accompanying Consolidated Balance Sheets, were $51.0 million and $54.8 million, respectively. The estimated non-current portion of such undiscounted insurance liabilities included in “Other long-term obligations” as of December 31, 2023 and 2022 were $229.8 million and $221.7 million, respectively. The current portion of anticipated insurance recoveries of $11.9 million and $16.0 million as of December 31, 2023 and 2022, respectively, were included in “Prepaid expenses and other” and the non-current portion of anticipated insurance recoveries of $48.8 million and $59.0 million as of December 31, 2023 and 2022, respectively, were included in “Other assets” in the accompanying Consolidated Balance Sheets. Foreign Operations The financial statements and transactions of our foreign subsidiaries are maintained in their functional currency and translated into U.S. dollars when preparing our consolidated financial statements. Statements of operations, comprehensive income, and cash flows are translated using weighted average monthly exchange rates, while balance sheets are translated at month-end exchange rates. Translation adjustments are recorded as “Accumulated other comprehensive loss,” a separate component of “Equity.” Income Taxes The Company follows the liability method of accounting for income taxes. Under this method, deferred income tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement and income tax bases of assets and liabilities as well as for net operating loss and tax credit carryforwards. Deferred income taxes are valued using enacted tax rates expected to be in effect when income taxes are paid or recovered, with the effect of a change in tax laws or rates recognized in the statement of operations in the periods in which such change is enacted. The ultimate realization of deferred income tax assets is dependent upon the generation of future taxable income during the period in which those temporary differences become deductible. Deferred income taxes are recorded net of a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. In making such determination, we consider all available evidence, including projections of future taxable income, tax-planning strategies, and recent results of operations. Tax benefits associated with uncertain tax positions are recognized only if it is more likely than not that the tax position would be sustained on its technical merits. For positions not meeting the “more likely than not” test, no tax benefit is recognized. To the extent interest and penalties may be assessed related to unrecognized tax benefits, we record accruals for such amounts as a component of the income tax provision. We had no unrecognized income tax benefits as of December 31, 2023 and 2022. Valuation of Share-Based Compensation Our share-based compensation plans and programs are administered by our Board of Directors or its Compensation and Personnel Committee. See Note 13 - Share-Based Compensation Plans of the notes to consolidated financial statements for additional information regarding these share-based compensation plans and programs. NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Continued) We recognize expense for all share-based payments issued to acquire goods or services based on the fair value of such payments. Compensation expense related to share-based awards is generally recognized on a straight-line basis over the requisite service period, which is the vesting period. The benefits of tax deductions in excess of recognized compensation expense are recognized in the Consolidated Statements of Operations when the underlying awards vest or are settled. New Accounting Pronouncements The Financial Accounting Standards Board (the “FASB”) has issued an Accounting Standards Update (“ASU”), which provides temporary optional expedients and exceptions to existing U.S. GAAP. This guidance is aimed at easing the financial reporting burdens related to reference rate reform, including the market transition from the London interbank offered rate (“LIBOR”), or other interbank offered rates, to alternative reference rates. Such accounting pronouncement, as amended, allows entities to account for and present certain contract modifications, which occur before December 31, 2024 and result from the transition to an alternative reference rate, as an event that does not require remeasurement at the modification date or reassessment of a previous accounting determination. In order to utilize such guidance, an entity must first conclude that the modified terms directly replace or have the potential to replace an eligible reference rate due to reference rate reform, and that any contemporaneous changes to other terms that change, or have the potential to change, the amount or timing of contractual cash flows are related to the replacement of a reference rate. During the second quarter of 2023, we amended our then existing credit agreement to change the reference rate from LIBOR to an interest rate based on the secured overnight financing rate, as administered by the Federal Reserve Bank of New York (“SOFR”). As such amendment was within the scope of the aforementioned guidance, we adopted this accounting pronouncement and utilized the optional expedients referenced above. We are not exposed to any other material contracts that reference LIBOR. The adoption of this accounting pronouncement did not have a material impact on our financial position and/or results of operations. In November 2023, the FASB issued an ASU, which expands the required disclosure for reportable segments. This guidance requires entities to disclose significant segment expenses and other segment items on an annual and interim basis and to provide in interim periods all segment disclosures which are currently required annually. This ASU additionally requires entities to disclose the title and position of the individual or the name of the group or committee identified as its chief operating decision-maker. Such guidance, which is required to be applied retrospectively, is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, although early adoption is permitted. While the adoption of this ASU will not have an impact on our financial position and/or results of operations, we are currently evaluating the impact to our segment disclosures. In December 2023, the FASB issued an ASU intended to enhance the transparency and decision-usefulness of income tax disclosures. Such guidance requires entities to provide additional information within their income tax rate reconciliation, including further disclosure of federal, state, and foreign income taxes and to provide more details about these reconciling items if a quantitative threshold is met. This guidance additionally requires expanded disclosure of income taxes paid, including amounts paid for federal, state, and foreign taxes. This ASU, which is required to be applied prospectively, is effective for fiscal years beginning after December 15, 2024, although early adoption and retrospective application is permitted. While the adoption of this ASU will not have an impact on our financial position and/or results of operations, we are currently evaluating the impact on our income tax disclosures, including the processes and controls around the collection of this information.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
Revenue from Contracts with Customers	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	REVENUE FROM CONTRACTS WITH CUSTOMERS The Company recognizes revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services by applying the following five step model: (1) Identify the contract with a customer A contract with a customer exists when: (a) the parties have approved the contract and are committed to perform their respective obligations, (b) the rights of the parties can be identified, (c) payment terms can be identified, (d) the arrangement has commercial substance, and (e) collectability of consideration is probable. Judgment is required when determining if the contractual criteria are met, specifically in the earlier stages of a project when a formally executed contract may not yet exist. In these situations, the Company evaluates all relevant facts and circumstances, including the existence of other forms of documentation or historical experience with our customers that may indicate a contractual agreement is in place and revenue should be recognized. In determining if the collectability of consideration is probable, the Company considers the customer’s ability and intention to pay such consideration through an evaluation of several factors, including an assessment of the creditworthiness of the customer and our prior collection history with such customer. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) (2) Identify the performance obligations in the contract At contract inception, the Company assesses the goods or services promised in a contract and identifies, as a separate performance obligation, each distinct promise to transfer goods or services to the customer. The identified performance obligations represent the “unit of account” for purposes of determining revenue recognition. In order to properly identify separate performance obligations, the Company applies judgment in determining whether each good or service provided is: (a) capable of being distinct, whereby the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and (b) distinct within the context of the contract, whereby the transfer of the good or service to the customer is separately identifiable from other promises in the contract. In addition, when assessing performance obligations within a contract, the Company considers the warranty provisions included within such contract. To the extent the warranty terms provide the customer with an additional service, other than assurance that the promised good or service complies with agreed upon specifications, such warranty is accounted for as a separate performance obligation. In determining whether a warranty provides an additional service, the Company considers each warranty provision in comparison to warranty terms which are standard in the industry. Our contracts are often modified through change orders to account for changes in the scope and price of the goods or services we are providing. Although the Company evaluates each change order to determine whether such modification creates a separate performance obligation, the majority of our change orders are for goods or services that are not distinct within the context of our original contract and, therefore, are not treated as separate performance obligations. (3) Determine the transaction price The transaction price represents the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to our customers. The consideration promised within a contract may include fixed amounts, variable amounts, or both. To the extent the performance obligation includes variable consideration, including contract bonuses and penalties that can either increase or decrease the transaction price, the Company estimates the amount of variable consideration to be included in the transaction price utilizing one of two prescribed methods, depending on which method better predicts the amount of consideration to which the entity will be entitled. Such methods include: (a) the expected value method, whereby the amount of variable consideration to be recognized represents the sum of probability-weighted amounts in a range of possible consideration amounts, and (b) the most likely amount method, whereby the amount of variable consideration to be recognized represents the single most likely amount in a range of possible consideration amounts. When applying these methods, the Company considers all information that is reasonably available, including historical, current, and estimates of future performance. The expected value method is typically utilized in situations where a contract contains a large number of possible outcomes while the most likely amount method is typically utilized in situations where a contract has only two possible outcomes. Variable consideration is included in the transaction price only to the extent it is probable, in the Company’s judgment, that a significant future reversal in the amount of cumulative revenue recognized under the contract will not occur when the uncertainty associated with the variable consideration is subsequently resolved. This threshold is referred to as the variable consideration constraint. In assessing whether to apply the variable consideration constraint, the Company considers if factors exist that could increase the likelihood or the magnitude of a potential reversal of revenue, including, but not limited to, whether: (a) the amount of consideration is highly susceptible to factors outside of the Company’s influence, such as the actions of third parties, (b) the uncertainty surrounding the amount of consideration is not expected to be resolved for a long period of time, (c) the Company’s experience with similar types of contracts is limited or that experience has limited predictive value, (d) the Company has a practice of either offering a broad range of price concessions or changing the payment terms and conditions of similar contracts in similar circumstances, and (e) the contract has a large number and broad range of possible consideration amounts. Pending change orders represent one of the most common forms of variable consideration included within contract value and typically 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. In estimating the transaction price for pending change orders, the Company considers all relevant facts, including documented correspondence with the customer regarding acknowledgment of and/or agreement with the modification, as well as historical experience with the customer or similar contractual circumstances. Based upon this assessment, the Company estimates the transaction price, including whether the variable consideration constraint should be applied. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Contract claims are another form of variable consideration which is common within our industry. Claim amounts represent revenue that has been recognized for contract modifications that are not submitted or are in dispute as to both scope and price. In estimating the transaction price for claims, the Company considers all relevant facts available. However, given the uncertainty surrounding claims, including the potential long-term nature of dispute resolution and the broad range of possible consideration amounts, there is an increased likelihood that any additional contract revenue associated with contract claims is constrained. The resolution of claims involves negotiations and, in certain cases, litigation. In the event litigation costs are incurred by us in connection with claims, such litigation costs are expensed as incurred, although we may seek to recover these costs. For some transactions, the receipt of consideration does not match the timing of the transfer of goods or services to the customer. For such contracts, the Company evaluates whether this timing difference represents a financing arrangement within the contract. Although rare, if a contract is determined to contain a significant financing component, the Company adjusts the promised amount of consideration for the effects of the time value of money when determining the transaction price of such contract. Although our customers may retain a portion of the contract price until completion of the project and final contract settlement, these retainage amounts are not considered a significant financing component as the intent of the withheld amounts is to provide the customer with assurance that we will complete our obligations under the contract rather than to provide financing to the customer. In addition, although we may be entitled to advanced payments from our customers on certain contracts, these advanced payments generally do not represent a significant financing component as the payments are used to meet working capital demands that can be higher in the early stages of a contract, as well as to protect us from our customer failing to meet its obligations under the contract. Changes in the estimates of transaction prices are recognized on a cumulative catch-up basis in the period in which the revisions to the estimates are made. Such changes in estimates can result in the recognition of revenue in a current period for performance obligations which were satisfied or partially satisfied in prior periods. Such changes in estimates may also result in the reversal of previously recognized revenue if the ultimate outcome differs from the Company’s previous estimate. (4) Allocate the transaction price to the performance obligations in the contract For contracts that contain multiple performance obligations, the Company allocates the transaction price to each performance obligation based on a relative standalone selling price. The Company determines the standalone selling price based on the price at which the performance obligation would have been sold separately in similar circumstances to similar customers. If the standalone selling price is not observable, the Company estimates the standalone selling price taking into account all available information such as market conditions and internal pricing guidelines. In certain circumstances, the standalone selling price is determined using an expected profit margin on anticipated costs related to the performance obligation. (5) Recognize revenue as performance obligations are satisfied The Company recognizes revenue at the time the related performance obligation is satisfied by transferring a promised good or service to its customers. A good or service is considered to be transferred when the customer obtains control. The Company can transfer control of a good or service and satisfy its performance obligations either over time or at a point in time. The Company transfers control of a good or service over time and, therefore, satisfies a performance obligation and recognizes revenue over time if one of the following three criteria are met: (a) the customer simultaneously receives and consumes the benefits provided by the Company’s performance as we perform, (b) the Company’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or (c) the Company’s performance does not create an asset with an alternative use to us, and we have an enforceable right to payment for performance completed to date. For our performance obligations satisfied over time, we recognize revenue by measuring the progress toward complete satisfaction of that performance obligation. The selection of the method to measure progress towards completion can be either an input method or an output method and requires judgment based on the nature of the goods or services to be provided. For our construction contracts, revenue is generally recognized over time as our performance creates or enhances an asset that the customer controls as it is created or enhanced. Our fixed price construction projects generally use a cost-to-cost input method to measure our progress towards complete satisfaction of the performance obligation as we believe it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost measure of progress, 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. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) For our unit price construction contracts, progress towards complete satisfaction is measured through an output method, such as the number of units produced or delivered, when our performance does not produce significant amounts of work in process or finished goods prior to complete satisfaction of such performance obligations. For our services contracts, revenue is also generally recognized over time as the customer simultaneously receives and consumes the benefits of our performance as we perform the service. For our fixed price service contracts with specified service periods, revenue is generally recognized on a straight-line basis over such service period when our inputs are expended evenly and the customer receives and consumes the benefits of our performance throughout the contract term. The timing of revenue recognition for the manufacturing of new build heat exchangers within our United States industrial services segment depends on the payment terms of the contract, as our performance does not create an asset with an alternative use to us. For those contracts for which we have a right to payment for performance completed to date at all times throughout our performance, inclusive of a cancellation, we recognize revenue over time. For these performance obligations, we use a cost-to-cost input method to measure our progress towards complete satisfaction of the performance obligation as we believe it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. However, for those contracts for which we do not have a right, at all times, to payment for performance completed to date, we recognize revenue at the point in time when control is transferred to the customer. For bill-and-hold arrangements, revenue is recognized when the customer obtains control of the heat exchanger, which may be prior to shipping if certain recognition criteria are met. For certain of our revenue streams, such as call-out repair and service work, outage services, refinery turnarounds, and specialty welding services that are performed under time and materials contracts, our progress towards complete satisfaction of such performance obligations is measured using an output method as the customer receives and consumes the benefits of our performance completed to date. Changes in Estimates Due to uncertainties inherent in the estimation process, as well as the significant judgment involved in determining variable consideration, it is possible that estimates of costs to complete a performance obligation, and/or our estimates of transaction prices, will be revised in the near term. For those performance obligations for which revenue is recognized using a cost-to-cost input method, changes in total estimated costs, and related progress towards complete satisfaction of the performance obligation, or changes in the estimate of transaction prices, are recognized on a cumulative catch-up basis in the period in which the revisions to the estimates are made. When the current estimate of total costs for a performance obligation indicates a loss, a provision for the entire estimated loss on the unsatisfied performance obligation is made in the period in which the loss becomes evident. Based on an evaluation of individual projects that had revisions to total estimated costs, or anticipated contract value, which resulted in a reduction of profitability in excess of $1.0 million, our operating results were negatively impacted during the years ended December 31, 2023, 2022, and 2021, as summarized in the following table (in thousands): 2023 2022 2021 United States electrical construction and facilities services $ 12,535 $ 33,463 $ 4,627 United States mechanical construction and facilities services 10,864 13,679 2,264 United States building services 5,658 1,261 — Total impact $ 29,057 $ 48,403 $ 6,891 During the year ended December 31, 2023, we recognized revenue of approximately $16.5 million on individual projects that were substantially complete in prior periods but had revisions to total estimated cost or anticipated contract value, which resulted in an increase to profitability in excess of $1.0 million. Of this amount, approximately $3.4 million was reported within our United States electrical construction and facilities services segment and approximately $13.1 million was reported within our United States mechanical construction and facilities services segment. There were no significant amounts of revenue recognized during the years ended December 31, 2022 or 2021 related to performance obligations satisfied in prior periods. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Disaggregation of Revenues Our revenues are principally derived from contracts to provide construction services relating to electrical and mechanical systems, as well as to provide a number of building services and industrial services to our customers. Our contracts are with many different customers in numerous industries. The following tables provide further disaggregation of our revenues by categories we use to evaluate our financial performance within each of our reportable segments (in thousands, except for percentages). Refer to Note 18 - Segment Information of the notes to consolidated financial statements for additional information on how we disaggregate our revenues by reportable segment. Due to continued growth in certain of our end markets, during 2023, we have expanded the market sectors included in the disclosure for each of our United States construction segments, as shown below. All prior period disclosures have been adjusted to additionally reflect these changes. 2023 % of 2022 % of 2021 % of United States electrical construction and facilities services: Network and communications market sector $ 934,455 34 % $ 801,052 33 % $ 621,139 30 % Commercial market sector 402,886 14 % 414,539 17 % 398,996 20 % Manufacturing and industrial market sector 394,804 14 % 301,606 12 % 230,894 11 % Healthcare market sector 242,931 9 % 178,348 7 % 107,442 5 % High-tech manufacturing market sector 140,471 5 % 88,544 4 % 35,196 2 % Institutional market sector 147,375 5 % 154,077 6 % 178,729 9 % Transportation market sector 167,976 6 % 166,563 7 % 196,313 10 % Water and wastewater market sector 21,234 1 % 21,251 1 % 14,962 1 % Hospitality and entertainment market sector 81,815 3 % 33,818 1 % 23,257 1 % Short duration projects (1) 186,722 7 % 211,797 9 % 185,277 9 % Service work 65,338 2 % 65,709 3 % 40,963 2 % 2,786,007 2,437,304 2,033,168 Less intersegment revenues (2,284) (4,190) (3,275) Total segment revenues $ 2,783,723 $ 2,433,114 $ 2,029,893 2023 % of 2022 % of 2021 % of United States mechanical construction and facilities services: Network and communications market sector $ 410,397 8 % $ 295,261 7 % $ 279,953 7 % Commercial market sector 1,115,993 22 % 1,079,872 25 % 1,042,751 27 % Manufacturing and industrial market sector 698,993 14 % 632,332 15 % 579,176 15 % Healthcare market sector 489,485 10 % 479,937 11 % 487,111 12 % High-tech manufacturing market sector 845,251 16 % 320,597 7 % 173,302 4 % Institutional market sector 316,255 6 % 331,727 8 % 263,285 7 % Transportation market sector 42,789 1 % 57,026 1 % 84,503 2 % Water and wastewater market sector 286,912 6 % 261,501 6 % 213,314 5 % Hospitality and entertainment market sector 52,919 1 % 44,615 1 % 66,059 2 % Short duration projects (1) 324,056 6 % 333,066 8 % 292,795 8 % Service work 500,853 10 % 467,156 11 % 446,786 11 % 5,083,903 4,303,090 3,929,035 Less intersegment revenues (9,100) (10,882) (6,835) Total segment revenues $ 5,074,803 $ 4,292,208 $ 3,922,200 _________________ (1) Represents those projects which generally are completed within three months or less. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) 2023 % of 2022 % of 2021 % of United States building services: Mechanical services $ 2,042,244 65 % $ 1,748,455 64 % $ 1,590,506 65 % Commercial site-based services 865,232 28 % 810,210 29 % 680,351 28 % Government site-based services 212,658 7 % 196,288 7 % 184,272 7 % Total segment revenues $ 3,120,134 $ 2,754,953 $ 2,455,129 2023 % of 2022 % of 2021 % of United States industrial services: Field services $ 991,466 85 % $ 972,894 87 % $ 853,143 86 % Shop services 176,324 15 % 145,873 13 % 133,264 14 % Total segment revenues $ 1,167,790 $ 1,118,767 $ 986,407 Total United States operations $ 12,146,450 $ 10,599,042 $ 9,393,629 2023 % of 2022 % of 2021 % of United Kingdom building services: Service work $ 210,414 48 % $ 221,123 46 % $ 261,889 51 % Project work 226,009 52 % 255,955 54 % 248,062 49 % Total segment revenues $ 436,423 $ 477,078 $ 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580 Contract Assets and Contract Liabilities The timing of revenue recognition may differ from the timing of invoicing to customers. Contract assets include unbilled amounts from our construction projects when revenues recognized under the cost-to-cost measure of progress exceed the amounts invoiced to our customers, as the amounts are not yet billable under the terms of our contracts. Such amounts are recoverable from our customers based upon various measures of performance, including achievement of certain milestones, completion of specified units, or completion of a contract. In addition, many of our time and materials arrangements, as well as our contracts to perform turnaround services within the United States industrial services segment, are billed in arrears pursuant to contract terms that are standard within the industry, resulting in contract assets and/or unbilled receivables being recorded as revenue is recognized in advance of billings. Also included in contract assets are amounts we seek or will seek to collect from customers or others for errors or changes in contract specifications or design, contract change orders or modifications in dispute or unapproved as to scope and/or price, or other customer-related causes of unanticipated additional contract costs (claims and unapproved change orders). Our contract assets do not include capitalized costs to obtain and fulfill a contract. Contract assets are generally classified as current within the Consolidated Balance Sheets. As of December 31, 2023 and 2022, contract assets included unbilled revenues for unapproved change orders of approximately $29.8 million and $36.0 million, respectively. Contract assets as of December 31, 2023 and 2022 additionally included $6.7 million and $3.8 million, respectively, associated with claims. There were $15.4 million of claims included within accounts receivable as of December 31, 2023. There were no claims included within accounts receivable as of December 31, 2022. There were contractually billed amounts and retention related to contracts with unapproved change orders and claims of approximately $157.7 million and $131.4 million as of December 31, 2023 and 2022, respectively. For contracts in claim status, contractually billed amounts will generally not be paid by the customer to us until final resolution of the related claims. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Contract liabilities from our construction contracts arise when amounts invoiced to our customers exceed revenues recognized under the cost-to-cost measure of progress. Contract liabilities additionally include advanced payments from our customers on certain contracts. Contract liabilities decrease as we recognize revenue from the satisfaction of the related performance obligation and are recorded as either current or long-term, depending upon when we expect to recognize such revenue. The long-term portion of contract liabilities is included in “Other long-term obligations” in the Consolidated Balance Sheets. Net contract liabilities in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Contract assets, current $ 269,885 $ 273,176 Contract assets, non-current — — Contract liabilities, current (1,595,109) (1,098,263) Contract liabilities, non-current (1,812) (2,273) Net contract liabilities $ (1,327,036) $ (827,360) Included within net contract liabilities were $1,261.1 million and $763.2 million of net contract liabilities on uncompleted construction projects as of December 31, 2023 and 2022, respectively, as follows (in thousands): December 31, 2023 December 31, 2022 Costs incurred on uncompleted construction contracts $ 15,100,829 $ 13,231,612 Estimated earnings, thereon 2,381,049 2,025,929 17,481,878 15,257,541 Less: billings to date 18,742,934 16,020,704 $ (1,261,056) $ (763,163) Contract assets and contract liabilities increased by approximately $2.0 million and $3.8 million, respectively, as a result of acquisitions made by us in 2023. Excluding the impact of acquisitions, net contract liabilities increased by approximately $497.9 million for the year ended December 31, 2023, predominantly due to an increase in net contract liabilities on our uncompleted construction projects, partially as a result of the timing of invoicing to our customers, which included customer deposits and advanced billings on several large projects in the earlier stages of completion, resulting in amounts invoiced exceeding the revenue recognized for such projects. There was no significant impairment of contract assets recognized during the periods presented. Contract Retentions As of December 31, 2023 and 2022, accounts receivable included $555.9 million and $456.9 million, respectively, of retainage billed under terms of our contracts. These retainage amounts represent amounts which have been contractually invoiced to customers where payments have been partially withheld pending the completion of the project. We estimate that approximately 88% of the retainage outstanding as of December 31, 2023 will be collected during 2024. As of December 31, 2023 and 2022, accounts payable included $93.6 million and $82.4 million, respectively, of retainage withheld under terms of our subcontracts. These retainage amounts represent amounts invoiced to the Company by our subcontractors where payments have been partially withheld pending the completion of their scope of work. We estimate that approximately 90% of the retainage outstanding as of December 31, 2023 will be paid during 2024. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Transaction Price Allocated to Remaining Unsatisfied Performance Obligations The following table presents the transaction price allocated to remaining unsatisfied performance obligations (“remaining performance obligations”) for each of our reportable segments and their respective percentages of total remaining performance obligations as of December 31, 2023 (in thousands, except for percentages): December 31, 2023 % of Total Remaining performance obligations: United States electrical construction and facilities services $ 2,387,844 27 % United States mechanical construction and facilities services 4,940,519 56 % United States building services 1,264,818 14 % United States industrial services 113,291 1 % Total United States operations 8,706,472 98 % United Kingdom building services 140,949 2 % Total operations $ 8,847,421 100 % Our remaining performance obligations at December 31, 2023 were $8.85 billion. Remaining performance obligations increase with awards of new contracts and decrease as we perform work and recognize revenue on existing contracts. We include a project within our remaining performance obligations at such time the project is awarded and agreement on contract terms has been reached. Our remaining performance obligations include amounts related to contracts for which a fixed price contract value is not assigned when a reasonable estimate of the total transaction price can be made. Remaining performance obligations include unrecognized revenues to be realized from uncompleted construction contracts. Although many of our construction contracts are subject to cancellation at the election of our customers, in accordance with industry practice, we do not limit the amount of unrecognized revenue included within remaining performance obligations for these contracts as the risk of cancellation is very low due to the inherent substantial economic penalty that our customers would incur upon cancellation or termination. We believe our reported remaining performance obligations for our construction contracts are firm and contract cancellations have not had a material adverse effect on us. Remaining performance obligations also include unrecognized revenues expected to be realized over the remaining term of service contracts. However, to the extent a service contract includes a cancellation clause which allows for the termination of such contract by either party without a substantive penalty, the remaining contract term, and therefore, the amount of unrecognized revenues included within remaining performance obligations, is limited to the notice period required for the termination. Our remaining performance obligations are comprised of: (a) original contract amounts, (b) change orders for which we have received written confirmations from our customers, (c) pending change orders for which we expect to receive confirmations in the ordinary course of business, (d) claim amounts that we have made against customers for which we have determined we have a legal basis under existing contractual arrangements and as to which the variable consideration constraint does not apply, and (e) other forms of variable consideration to the extent that such variable consideration has been included within the transaction price of our contracts. Such claim and other variable consideration amounts were immaterial for all periods presented. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Refer to the table below for additional information regarding our remaining performance obligations, including an estimate of when we expect to recognize such remaining performance obligations as revenue (in thousands): Within Greater than one year Remaining performance obligations: United States electrical construction and facilities services $ 1,978,179 $ 409,665 United States mechanical construction and facilities services 4,314,365 626,154 United States building services 1,157,845 106,973 United States industrial services 113,291 — Total United States operations 7,563,680 1,142,792 United Kingdom building services 94,711 46,238 Total operations $ 7,658,391 $ 1,189,030

Acquisitions Of Businesses

Acquisitions Of Businesses	12 Months Ended
Acquisitions Of Businesses	Dec. 31, 2023
Business Combinations [Abstract]
Acquisitions Of Businesses	ACQUISITIONS OF BUSINESSES Acquisitions are accounted for utilizing the acquisition method of accounting and the prices paid for them are allocated to their respective assets and liabilities based upon the estimated fair value of such assets and liabilities at the dates of their respective acquisition by us. During 2023, we acquired eight companies for total consideration of $99.6 million. Such acquisitions include: (a) a national energy efficiency specialty services firm, the results of operations of which have been included in our United States building services segment, and (b) seven companies, the results of operations of which were de minimis, consisting of: (i) three companies that have been included within our United States mechanical construction and facilities services segment, one of which provides mechanical and pipe fabrication services in the Midwestern region of the United States, and two of which add capabilities to our national fire protection services, and (ii) four mechanical services companies in the Western and Midwestern regions of the United States that have been included within our United States building services segment and enhance our presence in geographies where we have existing operations. In connection with these acquisitions, we acquired working capital of $9.1 million and other net liabilities of $6.1 million, including certain deferred tax liabilities, and have preliminarily ascribed $37.4 million to goodwill and $59.2 million to identifiable intangible assets. We expect that $29.6 million of the goodwill and identifiable intangible assets acquired in connection with these 2023 acquisitions will be deductible for tax purposes. During 2022, we acquired six companies for total consideration of $100.8 million. Such acquisitions include: (a) a company that provides electrical construction services in the Greater Boston area, the results of operations of which have been included in our United States electrical construction and facilities services segment, and (b) five companies that enhance our presence in geographies where we have existing operations, the results of operations of which were de minimis, consisting of: (i) two companies that provide fire protection services in the Northeastern and Southern regions of the United States, respectively, and that have been included within our United States mechanical construction and facilities services segment, (ii) two companies that specialize in either building automation and controls or mechanical services in the Southwestern and Southern regions of the United States, respectively, and that have been included within our United States building services segment, and (iii) a company that provides electrical construction services in the Midwestern region of the United States and that has been included within our United States electrical construction and facilities services segment. In connection with these acquisitions, we acquired working capital of $7.1 million and other net liabilities of $1.1 million, and have ascribed $28.9 million to goodwill and $65.9 million to identifiable intangible assets. We expect that all of the goodwill and identifiable intangible assets acquired in connection with these 2022 acquisitions will be deductible for tax purposes. During 2021, we acquired eight companies for total consideration of $131.2 million. Such acquisitions include: (a) two companies, the results of operations of which have been included within our United States mechanical construction and facilities services segment, consisting of: (i) a company that provides mechanical services within the Southern region of the United States and (ii) a company that provides fire protection services in the Midwestern region of the United States, (b) two companies that provide electrical construction services for a broad array of customers in the Midwestern region of the United States, the results of operations of which have been included in our United States electrical construction and facilities services segment, and (c) four companies, the results of operations of which have been included within our United States building services segment, consisting of: (i) a company that provides mechanical services across North Texas and (ii) three companies that enhance our presence in geographies where we have existing operations and provide either mechanical services or building NOTE 4 - ACQUISITIONS OF BUSINESSES (Continued) automation and controls solutions. In connection with these acquisitions, we acquired working capital of $22.9 million and other net liabilities of $0.6 million, including certain deferred tax liabilities, and have ascribed $38.3 million to goodwill and $70.6 million to identifiable intangible assets. We expect that $90.5 million of the goodwill and identifiable intangible assets acquired in connection with these 2021 acquisitions will be deductible for tax purposes. The purchase price allocation for one of the businesses acquired in 2023 is preliminary and subject to change during its measurement period. As we finalize such purchase price allocation, adjustments may be recorded relating to finalization of intangible asset valuations, tax matters, or other items. Although not expected to be significant, such adjustments may result in changes in the valuation of assets and liabilities acquired. The purchase price allocations for the other businesses acquired in 2023 as well as the businesses acquired in 2022 and 2021 have been finalized during their respective measurement periods with an insignificant impact.

Earnings Per Share

Earnings Per Share	12 Months Ended
Earnings Per Share	Dec. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table summarizes our calculation of Basic and Diluted Earnings per Common Share (“EPS”) for the years ended December 31, 2023, 2022, and 2021 (in thousands, except share and per share data): 2023 2022 2021 Numerator: Net income attributable to EMCOR Group, Inc. $ 632,994 $ 406,122 $ 383,532 Denominator: Weighted average shares outstanding used to compute basic earnings 47,358,467 49,931,940 54,068,982 Effect of dilutive securities—Share-based awards 205,791 204,322 278,552 Shares used to compute diluted earnings per common share 47,564,258 50,136,262 54,347,534 Basic earnings per common share $ 13.37 $ 8.13 $ 7.09 Diluted earnings per common share $ 13.31 $ 8.10 $ 7.06 The number of outstanding share-based awards excluded from the computation of diluted EPS for the years ended December 31, 2023, 2022, and 2021 because they would be anti-dilutive were 8,700, 4,926, and 9,250, respectively.

Inventories

Inventories	12 Months Ended
Inventories	Dec. 31, 2023
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Raw materials and construction materials $ 94,447 $ 74,014 Work in process 16,327 11,627 Inventories $ 110,774 $ 85,641 The increase in inventories as of December 31, 2023, compared to December 31, 2022, was a result of: (a) advanced purchases of materials and equipment for use on specific construction projects, in an effort to mitigate the impact of increased lead times, which have resulted from supply chain disruptions, (b) an increase in raw materials on hand to support our fabrication facilities given the growth in demand for our fire protection services, and (c) higher levels of work in process inventory within our United States industrial services segment given greater new build heat exchanger orders.

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
Property, Plant, and Equipment	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT Property, plant, and equipment in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Machinery and equipment $ 224,456 $ 206,249 Vehicles 76,489 68,858 Furniture and fixtures 27,415 25,253 Computer hardware/software 102,682 109,166 Land, buildings, and leasehold improvements 142,114 130,358 Construction in progress 13,514 6,060 Finance lease right-of-use assets (1) 4,932 6,117 591,602 552,061 Accumulated depreciation and amortization (412,224) (394,242) $ 179,378 $ 157,819 ____________________________________________ (1) Finance lease right-of-use assets are recorded net of accumulated amortization.

Goodwill, Identifiable Intangib

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets	GOODWILL, IDENTIFIABLE INTANGIBLE ASSETS, AND OTHER LONG-LIVED ASSETS Goodwill In connection with our acquisition of businesses, we have recorded goodwill, which represents the excess of the consideration transferred over the fair value of the net tangible and identifiable intangible assets acquired. Our goodwill balance at December 31, 2023 and 2022 was $956.5 million and $919.2 million, respectively, with goodwill attributable to companies acquired in 2023 and 2022 valued at $37.4 million and $28.9 million, respectively. Goodwill is not amortized but instead allocated to its respective reporting unit and evaluated for impairment annually, or more frequently if events or circumstances indicate that the carrying amount of goodwill may be impaired. We have determined that our reporting units are consistent with the reportable segments identified in Note 18 - Segment Information of the notes to consolidated financial statements. As of December 31, 2023, approximately 18.6% of our goodwill related to our United States electrical construction and facilities services segment, approximately 33.3% of our goodwill related to our United States mechanical construction and facilities services segment, approximately 36.2% of our goodwill related to our United States building services segment and approximately 11.9% of our goodwill related to our United States industrial services segment. Absent any earlier identified impairment indicators, we perform our annual goodwill impairment assessment on October 1 each fiscal year. Qualitative indicators that may trigger the need for interim quantitative impairment testing include, among others, deterioration in macroeconomic conditions, declining financial performance, deterioration in the operational environment, or an expectation of selling or disposing of a portion of a reporting unit. Additionally, an interim impairment test may be triggered by a significant change in business climate, a loss of a significant customer, increased competition, or a sustained decrease in share price. In assessing whether our goodwill is impaired, we compare the fair value of the reporting unit to its carrying amount, including goodwill. If the fair value exceeds the carrying amount, no impairment is recognized. However, if the carrying amount of the reporting unit exceeds the fair value, the goodwill of the reporting unit is impaired and an impairment loss in the amount of the excess is recognized and charged to operations. We performed our annual impairment assessment of all reporting units as of October 1, 2023, and determined there was no impairment of goodwill. In completing our annual impairment assessment, we determined the fair value of each of our reporting units using an income approach whereby fair value was calculated utilizing discounted estimated future cash flows, assuming a risk-adjusted industry weighted average cost of capital. The weighted average cost of capital used in our annual impairment testing was 10.9% for our United States construction segments, 11.2% for our United States building services segment, and 11.0% for our United States industrial services segment. These weighted average cost of capital estimates were developed with the assistance of an independent third-party valuation specialist and reflect the overall level of inherent risk within the respective reporting unit and the rate of return a market participant would expect to earn. Our cash flow projections were derived from our most recent internal forecasts of anticipated revenue growth rates and operating margins, with cash flows beyond the discrete forecast period estimated using a terminal value calculation which incorporated historical and forecasted trends, an estimate of long-term growth rates, and assumptions about the future demand for our services. The perpetual growth rate used for our annual testing was 2.5% for all of our reporting units. NOTE 8 - GOODWILL, IDENTIFIABLE INTANGIBLE ASSETS, AND OTHER LONG-LIVED ASSETS (Continued) For the years ended December 31, 2022 and 2021, no impairment of our goodwill was recognized. Due to the inherent uncertainties involved in making estimates, our assumptions may change in future periods. Estimates and assumptions made for purposes of our goodwill impairment testing may prove to be inaccurate predictions of the future, and other factors used in assessing fair value, such as the weighted average cost of capital, are outside the control of management. Unfavorable changes in certain of these key assumptions may affect future testing results. For example, keeping all other assumptions constant, a 50 basis point increase in the weighted average cost of capital would cause the estimated fair values of our United States electrical construction and facilities services segment, our United States mechanical construction and facilities services segment, our United States building services segment, and our United States industrial services segment to decrease by approximately $115.2 million, $249.9 million, $84.2 million, and $25.2 million, respectively. In addition, keeping all other assumptions constant, a 50 basis point reduction in the perpetual growth rate would cause the estimated fair values of our United States electrical construction and facilities services segment, our United States mechanical construction and facilities services segment, our United States building services segment, and our United States industrial services segment to decrease by approximately $56.5 million, $137.1 million, $40.4 million, and $9.3 million, respectively. Given the amounts by which the fair value exceeds the carrying value for each of our reporting units, the decreases in estimated fair values described above would not have significantly impacted the results of our 2023 impairment tests. Further, for each of our reporting units, a 10% decline in the estimated fair value of such reporting unit, due to other changes in our assumptions, including forecasted future cash flows, would not have significantly impacted the results of our 2023 impairment tests. The changes in the carrying amount of goodwill by reportable segment during the years ended December 31, 2023 and 2022 were as follows (in thousands): United States United States United States United States Total Balance at December 31, 2021 $ 159,512 $ 303,887 $ 312,781 $ 114,088 $ 890,268 Acquisitions 17,601 6,942 4,340 — 28,883 Intersegment transfers 900 4,500 (5,400) — — Balance at December 31, 2022 178,013 315,329 311,721 114,088 919,151 Acquisitions — 4,524 32,874 — 37,398 Intersegment transfers — (1,500) 1,500 — — Balance at December 31, 2023 $ 178,013 $ 318,353 $ 346,095 $ 114,088 $ 956,549 The aggregate goodwill balance as of December 31, 2021 included $493.6 million of accumulated impairment charges, which were comprised of $139.5 million within the United States building services segment and $354.1 million within the United States industrial services segment. Identifiable Intangible Assets and Other Long-Lived Assets Our identifiable intangible assets, arising out of the acquisition of businesses, include customer relationships, subsidiary trade names, developed technology/vendor network, and contract backlog, all of which are subject to amortization. In addition, our identifiable intangible assets include certain other subsidiary trade names, which are indefinite-lived and therefore not subject to amortization. Absent earlier indicators of impairment, we test for impairment of subsidiary trade names that are not subject to amortization on an annual basis (October 1). In performing this test, we calculate the fair value of each trade name using the “relief from royalty payments” methodology. This approach involves two steps: (a) estimating reasonable royalty rates for each trade name and (b) applying these royalty rates to a net revenue stream and discounting the resulting cash flows to determine fair value. This fair value is then compared with the carrying value of each trade name. If the carrying amount of the trade name is greater than the implied fair value of the trade name, an impairment in the amount of the excess is recognized and charged to operations. For the years ended December 31, 2023, 2022, and 2021, no impairment of our indefinite-lived trade name intangible assets was recognized. NOTE 8 - GOODWILL, IDENTIFIABLE INTANGIBLE ASSETS, AND OTHER LONG-LIVED ASSETS (Continued) We review for impairment of identifiable intangible assets that are being amortized as well as other long-lived assets whenever facts and circumstances indicate that their carrying values may not be fully recoverable. This test compares their carrying values to the undiscounted pre-tax cash flows expected to result from the use of the assets. If the assets are impaired, the assets are written down to their fair values, generally determined based on their discounted estimated future cash flows. During the quarter ended September 30, 2023, we identified facts and circumstances that indicated the carrying values of certain long-lived assets within our United States mechanical construction and facilities services segment may not be fully recoverable. As a result, we determined that these assets were impaired, and, during the third quarter of 2023, recognized a $2.4 million impairment charge. For the years ended December 31, 2023, 2022, and 2021, there were no other indicators of impairment with respect to identifiable intangible assets that are being amortized as well as other long-lived assets. Identifiable intangible assets as of December 31, 2023 and 2022 consisted of the following (in thousands): December 31, 2023 Gross Accumulated Accumulated Impairment Charge Total Customer relationships $ 807,766 $ (482,594) $ (4,834) $ 320,338 Trade names (indefinite-lived) 299,271 — (58,933) 240,338 Developed technology/Vendor network 95,661 (78,788) — 16,873 Trade names (finite-lived) 35,991 (27,800) — 8,191 Contract backlog 84,845 (84,553) — 292 Total $ 1,323,534 $ (673,735) $ (63,767) $ 586,032 December 31, 2022 Gross Accumulated Accumulated Total Customer relationships $ 762,516 $ (427,211) $ (4,834) $ 330,471 Trade names (indefinite-lived) 289,121 — (58,933) 230,188 Developed technology/Vendor network 95,661 (74,238) — 21,423 Trade names (finite-lived) 33,791 (25,690) — 8,101 Contract backlog 83,245 (79,453) — 3,792 Total $ 1,264,334 $ (606,592) $ (63,767) $ 593,975 Identifiable intangible assets attributable to businesses acquired in 2023 and 2022 have been valued at $59.2 million and $65.9 million, respectively, and consist of customer relationships, trade names, and contract backlog. See Note 4 - Acquisitions of Businesses of the notes to consolidated financial statements for additional information with respect to acquisitions. Identifiable intangible assets are amortized in a manner that best approximates the pattern in which the economic benefits of such assets are consumed, which is generally on a straight-line basis. The weighted average amortization periods for the unamortized balances remaining are, in the aggregate, approximately 7.00 years, which are comprised of the following: 7.25 years for customer relationships, 5.75 years for trade names, and 3.75 years for developed technology/vendor network. Amortization expense related to identifiable intangible assets with finite lives was $67.1 million, $61.3 million, and $64.1 million for the years ended December 31, 2023, 2022, and 2021, respectively. NOTE 8 - GOODWILL, IDENTIFIABLE INTANGIBLE ASSETS, AND OTHER LONG-LIVED ASSETS (Continued) The following table presents the estimated future amortization expense of identifiable intangible assets in the following years (in thousands): 2024 $ 63,873 2025 62,369 2026 55,782 2027 42,583 2028 33,818 Thereafter 87,269 $ 345,694 Other Considerations As referenced above, impairment testing is based upon assumptions and estimates determined by management from a review of our operating results and business plans as well as forecasts of anticipated growth rates and margins, among other considerations. In addition, estimates of weighted average costs of capital are developed with the assistance of an independent third-party valuation specialist. These assumptions and estimates may change in future periods, especially in times of uncertain economic conditions and rising interest rates. Significant adverse changes to external market conditions or our internal forecasts, if any, could result in future impairment charges. It is not possible at this time to determine if any future impairment charge will result or, if it does, whether such a charge would be material to our results of operations.

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2023
Debt Disclosure [Abstract]
Debt	DEBT Excluding finance lease liabilities, we had no outstanding debt as of December 31, 2023. Refer to Note 16 - Leases of the notes to consolidated financial statements for additional information regarding our finance leases, including outstanding balances. Debt in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2022 (in thousands): December 31, 2022 Term loan $ 242,813 Unamortized debt issuance costs (2,080) Finance lease liabilities 6,459 Total debt 247,192 Less: current maturities 15,567 Total long-term debt $ 231,625 Credit Agreement Until December 20, 2023, we had a credit agreement that was entered into on March 2, 2020, which provided for a $1.3 billion revolving credit facility (the “2020 Revolving Credit Facility”) and a $300.0 million term loan (the “2020 Term Loan”). On December 20, 2023, we amended and restated such agreement (as amended and restated, the “2023 Credit Agreement”) to provide for a $1.3 billion revolving credit facility (the “2023 Revolving Credit Facility”) expiring December 20, 2028. If additional lenders are identified and/or existing lenders are willing to increase their current commitments, we may increase the 2023 Revolving Credit Facility by an amount equal to the greater of: (a) $900 million or (b) the Company’s Adjusted EBITDA (as such term is defined in the 2023 Credit Agreement) for the twelve-month period ending immediately prior to the increase in commitment. We may allocate up to $600.0 million of available capacity under the 2023 Revolving Credit Facility to letters of credit for our account or for the account of any of our subsidiaries. There were no direct borrowings outstanding under the 2023 Revolving Credit Facility as of December 31, 2023 or the 2020 Revolving Credit Facility as of December 31, 2022. However, outstanding letters of credit reduce the available capacity under these facilities, and as of December 31, 2023 and 2022, we had $116.7 million and $71.3 million of letters of credit outstanding, respectively. The balance of the 2020 Term Loan as of December 31, 2022 was $242.8 million. NOTE 9 - DEBT (Continued) At the Company’s election, borrowings under the 2023 Revolving Credit Facility bear interest at either: (1) a base rate plus a margin of 0.125% to 0.875%, depending on the Company’s Leverage Ratio (as such term is defined in the 2023 Credit Agreement), or (2) a rate equal to the secured overnight financing rate as administered by the Federal Reserve Bank of New York for the applicable tenor plus 0.10% (“Adjusted Term SOFR”) plus a margin of 1.125% to 1.875%, depending on the Company’s Leverage Ratio. The base rate is determined by the greater of: (a) the prime commercial lending rate announced by Bank of Montreal from time to time, (b) the federal funds effective rate, plus ½ of 1.00%, (c) Adjusted Term SOFR for a one-month tenor, plus 1.00%, or (d) 0.00%. A commitment fee is payable on the average daily unused amount of the 2023 Revolving Credit Facility, which ranges from 0.125% to 0.25%, depending on the Company’s Leverage Ratio. The fee was 0.125% of the unused amount as of December 31, 2023. Fees for letters of credit issued under the 2023 Revolving Credit Facility range from 0.85% to 1.875% of the respective face amounts of outstanding letters of credit, depending on the nature of the letter of credit, and are computed depending on the Company’s Leverage Ratio. We capitalized an additional $3.4 million of debt issuance costs associated with the 2023 Credit Agreement. Debt issuance costs are amortized over the life of the agreement as part of interest expense. Obligations under the 2023 Credit Agreement are guaranteed by most of our direct and indirect subsidiaries and are secured by substantially all of our assets. The 2023 Credit Agreement contains customary covenants providing for, among other things, the maintenance of certain financial ratios and certain limitations on the payment of dividends, common stock repurchases, investments, acquisitions, indebtedness, and capital expenditures. We were in compliance with all such covenants as of December 31, 2023.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS For disclosure purposes, we utilize a fair value hierarchy to categorize qualifying assets and liabilities into three broad levels based on the priority of the inputs used to determine their fair values. The hierarchy, which gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities and the lowest priority to unobservable inputs, is comprised of the following three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets and liabilities. Level 2 – Observable inputs, other than Level 1 inputs, that are directly or indirectly observable for the asset or liability, including quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Significant unobservable inputs that reflect the reporting entity’s own assumptions. Recurring Fair Value Measurements The following tables summarize the assets and liabilities carried at fair value measured on a recurring basis as of December 31, 2023 and 2022 (in thousands): Assets at Fair Value as of December 31, 2023 Asset Category Level 1 Level 2 Level 3 Total Cash and cash equivalents (1) $ 789,750 $ — $ — $ 789,750 Deferred compensation plan assets (2) 47,315 — — 47,315 Total $ 837,065 $ — $ — $ 837,065 _________________ (1) Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2023, we had $497.3 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. (2) Deferred compensation plan assets are classified as “Other assets” in the Consolidated Balance Sheets. NOTE 10 - FAIR VALUE MEASUREMENTS (Continued) Assets at Fair Value as of December 31, 2022 Asset Category Level 1 Level 2 Level 3 Total Cash and cash equivalents (1) $ 456,439 $ — $ — $ 456,439 Deferred compensation plan assets (2) 36,882 — — 36,882 Restricted cash (3) 629 — — 629 Total $ 493,950 $ — $ — $ 493,950 _________________ (1) Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2022, we had $209.4 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. (2) Deferred compensation plan assets are classified as “Other assets” in the Consolidated Balance Sheets. (3) Restricted cash is classified as “Prepaid expenses and other” in the Consolidated Balance Sheets. Restricted cash primarily represents cash held in account for use on customer contracts. Nonrecurring Fair Value Measurements We have recorded goodwill and identifiable intangible assets in connection with our business acquisitions. Such assets are measured at fair value at the time of acquisition based on valuation techniques that appropriately represent the methods which would be used by other market participants in determining fair value. In addition, goodwill, intangible assets, and certain other long-lived assets are tested for impairment using similar valuation methodologies to determine the fair value of such assets. Periodically, we engage an independent third-party valuation specialist to assist with the valuation process, including the selection of appropriate methodologies and the development of market-based assumptions. The inputs used for these nonrecurring fair value measurements represent Level 3 inputs. Fair Value of Financial Instruments We believe that the carrying values of our financial instruments, which include accounts receivable and other financing commitments, approximate their fair values due primarily to their short-term maturities and low risk of counterparty default. Although there were no outstanding borrowings under our 2023 Credit Agreement as of December 31, 2023, the carrying value of any debt associated with this agreement would approximate its fair value due to the variable rate on such debt.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES For the years ended December 31, 2023, 2022, and 2021, our income tax provision was calculated based on income before income taxes as follows (in thousands): 2023 2022 2021 United States $ 844,002 $ 523,273 $ 497,421 Foreign 28,851 35,477 31,882 $ 872,853 $ 558,750 $ 529,303 Foreign income for each of the years ended December 31, 2023, 2022, and 2021 was predominantly earned in the United Kingdom. The income tax provision for the years ended December 31, 2023, 2022, and 2021 consisted of the following (in thousands): 2023 2022 2021 Current provision: Federal $ 187,463 $ 100,707 $ 95,782 State and local 62,316 36,547 35,883 Foreign 6,396 4,891 4,420 256,175 142,145 136,085 Deferred (benefit) provision (16,651) 10,483 9,517 $ 239,524 $ 152,628 $ 145,602 NOTE 11 - INCOME TAXES (Continued) For the year ended December 31, 2023, our income tax provision was $239.5 million compared to $152.6 million for the year ended December 31, 2022 and $145.6 million for the year ended December 31, 2021. The increase in the income tax provision year-over-year was primarily due to increased income before income taxes. The income tax rates on income before income taxes for the years ended December 31, 2023, 2022, and 2021, were 27.5%, 27.3%, and 27.5%, respectively. Items accounting for the differences between income taxes computed at the federal statutory rate and the income tax provision for the years ended December 31, 2023, 2022, and 2021 were as follows (in thousands): 2023 2022 2021 Federal income taxes at the statutory rate $ 183,230 $ 117,338 $ 111,118 State and local income taxes, net of federal tax benefits 46,752 29,519 31,257 Permanent differences 9,513 5,261 5,316 Foreign income taxes (including UK statutory rate changes) 640 (155) (2,241) Other (611) 665 152 $ 239,524 $ 152,628 $ 145,602 As of December 31, 2023, we had undistributed foreign earnings from certain foreign subsidiaries of approximately $167.3 million. Based on our evaluation, and given that a significant portion of such earnings were subject to tax in prior periods, or are indefinitely reinvested, we have concluded that any taxes associated with the repatriation of such foreign earnings would be immaterial. As of December 31, 2023, the amount of cash held by these foreign subsidiaries was approximately $135.0 million which, if repatriated, should not result in any material federal or state income taxes. We file a consolidated federal income tax return including all of our U.S. subsidiaries with the Internal Revenue Service. We additionally file income tax returns with various state, local, and foreign tax agencies. Our income tax returns are subject to audit by various taxing authorities and are currently under examination for the years 2017 through 2021. On March 11, 2021, the American Rescue Plan Act was signed into law. Such act includes certain tax provisions that could have an impact on the Company in future periods, including expanded limits on compensation deductions under Section 162(m) of the Internal Revenue Code for tax years beginning after December 31, 2026. We are currently evaluating the impact that this act may have on our financial position and/or results of operations; however, we anticipate that the expanded provisions of Section 162(m) will result in an increase in our effective income tax rate for years beginning after December 31, 2026. On August 16, 2022, the Inflation Reduction Act of 2022 (the “Inflation Reduction Act”) was signed into law. For tax years beginning after December 31, 2022, the Inflation Reduction Act creates a 15% corporate alternative minimum tax on profits of corporations whose average annual adjusted financial statement income exceeds $1.0 billion for any consecutive three-tax-year period preceding the then current tax year. Based on our average annual income for the preceding three years, which was below the aforementioned $1.0 billion threshold, as well as the fact that our effective federal income tax rate is in excess of the 15% alternative minimum tax rate, this alternative minimum tax did not have an impact on our financial position and/or results of operations for the year ended December 31, 2023. Legislation has been enacted in the United Kingdom to implement measures in concert with the Base Erosion and Profit Shifting Pillar Two framework for international taxation developed by the member countries of the Organization for Economic Co-operation and Development (the “Pillar Two Model Rules”). The Pillar Two Model Rules are intended to ensure that multinational enterprises pay a minimum 15% effective tax rate in every jurisdiction in which they operate. Given that our effective income tax rate in all jurisdictions in which we operate is in excess of such 15% minimum rate, we do not anticipate that these rules will have a material effect on our tax provision or effective income tax rate; however, we continue to monitor evolving tax legislation in the jurisdictions in which we operate. NOTE 11 - INCOME TAXES (Continued) Deferred income tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement and income tax bases of assets and liabilities. The deferred income tax assets and deferred income tax liabilities recorded as of December 31, 2023 and 2022 were as follows (in thousands): December 31, 2023 December 31, 2022 Deferred income tax assets: Excess of amounts expensed for financial statement purposes over amounts deducted for income tax purposes: Insurance liabilities $ 59,667 $ 57,278 Operating lease liabilities 92,410 78,391 Deferred compensation 54,313 40,682 Other (including liabilities and reserves) 40,110 35,584 Total deferred income tax assets 246,500 211,935 Valuation allowance for deferred tax assets (4,385) (3,580) Net deferred income tax assets 242,115 208,355 Deferred income tax liabilities: Costs capitalized for financial statement purposes and deducted for income tax purposes: Goodwill and identifiable intangible assets (165,073) (153,767) Operating lease right-of-use assets (85,883) (73,134) Depreciation of property, plant, and equipment (30,075) (28,435) Pension asset (4,660) (4,082) Other (13,063) (10,500) Total deferred income tax liabilities (298,754) (269,918) Net deferred income tax liabilities $ (56,639) $ (61,563) Our net deferred income tax liabilities of $56.6 million and $61.6 million as of December 31, 2023 and 2022, respectively, were included in “Other long-term obligations” in the accompanying Consolidated Balance Sheet. Valuation allowances are established when necessary to reduce deferred income tax assets when it is more likely than not that a tax benefit will not be realized. As of December 31, 2023 and 2022, the total valuation allowance on deferred income tax assets, related to state and local net operating losses, foreign net operating losses, and foreign income tax credit carryovers, was approximately $4.4 million and $3.6 million, respectively. The increase in our valuation allowances at December 31, 2023 was a result of the recognition of additional deferred tax assets related to net operating loss carryovers and foreign income tax credit carryovers that we determined we would likely not be able to utilize.

Common Stock

Common Stock	12 Months Ended
Common Stock	Dec. 31, 2023
Stockholders' Equity Note [Abstract]
Common Stock	COMMON STOCK As of December 31, 2023 and 2022, there were 47,047,265 and 47,666,725 shares of our common stock outstanding, respectively. We have paid quarterly dividends since October 25, 2011. We currently pay a regular quarterly dividend of $0.18 per share. Subsequent to December 31, 2023, our Board of Directors announced its intention to increase the regular quarterly dividend to $0.25 per share commencing with the dividend to be paid in April 2024. In September 2011, the Board authorized a share repurchase program allowing us to begin repurchasing shares of our outstanding common stock. Subsequently, the Board has from time to time increased the amount authorized for repurchases under such program. Since the inception of the repurchase program, the Board has authorized us to repurchase up to $2.15 billion of our outstanding common stock. During the year ended December 31, 2023, we repurchased approximately 0.8 million shares of our common stock for approximately $128.7 million. Since the inception of the repurchase program through December 31, 2023, we have repurchased approximately 25.8 million shares of our common stock for approximately $1.89 billion. As of December 31, 2023, there remained authorization for us to repurchase approximately $261.1 million of our shares. The repurchase program has no expiration date, does not obligate the Company to acquire any particular amount of common stock, and may be suspended, recommenced, or discontinued at any time or from time to time without prior notice. We may repurchase our shares from time to time to the extent permitted by securities laws and other legal requirements, including provisions in our 2023 Credit Agreement placing limitations on such repurchases. The Inflation Reduction Act, which was enacted into law on August 16, 2022, imposes a nondeductible excise tax of 1% on the fair value of net stock repurchases in excess of share issuances made by publicly traded U.S. corporations, effective for repurchases after December 31, 2022. The applicable excise tax for the year ended December 31, 2023 was approximately $1.0 million and has been included as a component of treasury stock as it represents a direct cost associated with the repurchase of our common stock.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
Share-Based Compensation Plans	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation Plans	SHARE-BASED COMPENSATION PLANS We have an incentive plan under which stock awards, stock units, and other share-based compensation may be granted to officers, non-employee directors, and key employees of the Company. Under the terms of this plan, 3,250,000 shares were authorized, and 692,720 shares remain available for grant or issuance as of December 31, 2023. Any issuances under this plan are valued at the fair market value of our common stock on the grant date. Forfeitures are recognized as they occur. The following table summarizes activity regarding restricted stock units since December 31, 2020: Shares Weighted Balance, December 31, 2020 397,918 $ 73.16 Granted 129,859 $ 96.32 Forfeited (2,242) $ 78.86 Vested (121,067) $ 77.86 Balance, December 31, 2021 404,468 $ 79.16 Granted 107,621 $ 123.52 Forfeited (4,665) $ 105.88 Vested (189,830) $ 67.40 Balance, December 31, 2022 317,594 $ 100.83 Granted 103,024 $ 156.06 Forfeited (3,018) $ 118.59 Vested (122,751) $ 90.38 Balance, December 31, 2023 294,849 $ 124.30 An aggregate of 34,196 restricted stock units granted to current non-employee directors vested as of December 31, 2023, but, at the election of such directors, issuance has been deferred for up to 10 years from the date of vest. In addition, an aggregate of 6,086 restricted stock units granted to former employees vested as of December 31, 2023 but, in accordance with plan documents, were issued in January 2024. NOTE 13 - SHARE-BASED COMPENSATION PLANS (Continued) We recognized approximately $13.7 million, $12.1 million, and $11.1 million of compensation expense for stock units awarded to non-employee directors and employees pursuant to our incentive plan for the years ended December 31, 2023, 2022, and 2021, respectively. We have approximately $11.4 million of compensation expense, net of income taxes, which will be recognized over the remaining vesting periods of up to 3 years. The income tax benefit derived in 2023, 2022, and 2021 as a result of share-based compensation was approximately $3.3 million, $3.9 million, and $2.6 million, respectively, of which approximately $1.7 million, $1.7 million, and $0.8 million, respectively, represented excess tax benefits. Through December 31, 2023, we sponsored an employee stock purchase plan, which generally allowed our corporate employees and non-union employees of our United States subsidiaries to purchase up to an aggregate of 3,000,000 of our shares. This plan was terminated subsequent to December 31, 2023.

Retirement Plans

Retirement Plans	12 Months Ended
Retirement Plans	Dec. 31, 2023
Retirement Benefits [Abstract]
Retirement Plans	RETIREMENT PLANS Defined Benefit Plans The funded status of our defined benefit plans, which represents the difference between the fair value of plan assets and the projected benefit obligations, is recognized in the Consolidated Balance Sheets with a corresponding adjustment to accumulated other comprehensive income (loss). Gains and losses for the differences between actuarial assumptions and actual results are recognized through accumulated other comprehensive income (loss). These amounts will be subsequently recognized as net periodic pension cost (income) within the Consolidated Statement of Operations, as described further below. United Kingdom Retirement Plan Our United Kingdom subsidiary has a defined benefit pension plan covering all eligible employees (the “UK Plan”); however, no individual joining the company after October 31, 2001 may participate in the UK Plan. On May 31, 2010, we curtailed the future accrual of benefits for active employees under such plan. The change in benefit obligations and assets of the UK Plan for the years ended December 31, 2023 and 2022 consisted of the following components (in thousands): 2023 2022 Change in pension benefit obligation Benefit obligation at beginning of year $ 193,956 $ 349,147 Interest cost 9,722 5,693 Actuarial loss (gain) 651 (116,372) Benefits paid (10,411) (11,095) Foreign currency exchange rate changes 10,179 (33,417) Benefit obligation at end of year 204,097 193,956 Change in pension plan assets Fair value of plan assets at beginning of year 210,284 356,532 Actual return (loss) on plan assets 10,563 (105,544) Employer contributions 1,564 4,875 Benefits paid (10,411) (11,095) Foreign currency exchange rate changes 11,077 (34,484) Fair value of plan assets at end of year 223,077 210,284 Funded status at end of year $ 18,980 $ 16,328 The funded status of the UK Plan of $19.0 million and $16.3 million as of December 31, 2023 and 2022, respectively, is included in “Other assets” in the accompanying Consolidated Balance Sheets. No plan assets are expected to be returned to us during the year ending December 31, 2024. NOTE 14 - RETIREMENT PLANS (Continued) The assumptions used to determine benefit obligations of the UK Plan as of December 31, 2023 and 2022 were as follows: 2023 2022 Discount rate 4.8 % 5.0 % The components of net periodic pension cost (income) of the UK Plan for the years ended December 31, 2023, 2022, and 2021 were as follows (in thousands): 2023 2022 2021 Interest cost $ 9,722 $ 5,693 $ 5,326 Expected return on plan assets (11,417) (12,088) (12,726) Amortization of unrecognized loss 2,611 2,073 3,642 Net periodic pension cost (income) $ 916 $ (4,322) $ (3,758) The assumptions used to determine net periodic pension cost of the UK Plan for the years ended December 31, 2023, 2022, and 2021 were as follows: 2023 2022 2021 Discount rate 5.0 % 1.8 % 1.4 % Annual rate of return on plan assets 5.7 % 3.9 % 3.9 % The annual rate of return on plan assets has been determined by modeling possible returns using the actuary’s portfolio return calculator and the fair value of plan assets. This approach models the long term expected returns of the various asset classes held in the portfolio and takes into account the additional benefits of holding a diversified portfolio. For measurement purposes of the liability, the annual rate of inflation of covered pension benefits assumed for both 2023 and 2022 was 2.8%. Amounts pertaining to the UK Plan not yet reflected in net periodic pension cost and included in accumulated other comprehensive loss were as follows (in thousands): December 31, 2023 December 31, 2022 Unrecognized actuarial losses $ 82,344 $ 79,313 Actuarial gains and losses are amortized using a corridor approach whereby cumulative gains and losses in excess of the greater of 10% of the pension benefit obligation or the fair value of plan assets are amortized over the average life expectancy of plan participants. The amortization period for 2023 was 23 years. The reclassification adjustment, net of income taxes, for the UK Plan from accumulated other comprehensive loss into net periodic pension cost was approximately $2.0 million for the year ended December 31, 2023, approximately $1.6 million for the year ended December 31, 2022, and approximately $2.9 million for the year ended December 31, 2021. The estimated unrecognized loss for the UK Plan that will be amortized from accumulated other comprehensive loss into net periodic pension cost over the next year is approximately $2.0 million, net of income taxes. NOTE 14 - RETIREMENT PLANS (Continued) Plan Assets The investment policies and strategies for the assets of the UK Plan are established by its trustees (who are independent of the Company) to achieve a reasonable balance between risk, likely return, and administration expense, as well as to maintain investment balances at a level to meet minimum funding requirements. In order to ensure that an appropriate investment strategy is in place, an analysis of the UK Plan’s assets and liabilities is completed periodically. Target allocation percentages vary over time depending on the perceived risk and return potential of various asset classes and market conditions. The weighted average asset allocations and weighted average target allocations at December 31, 2023 and 2022 were as follows: Asset Category Target Asset Allocation 2023 Actual December 31, 2023 Target Asset Allocation 2022 Actual December 31, 2022 Debt 90.0 % 87.1 % 75.0 % 80.7 % Cash and cash equivalents — % 3.9 % 15.0 % 9.4 % Real estate 10.0 % 9.0 % 10.0 % 9.9 % Total 100.0 % 100.0 % 100.0 % 100.0 % Plan assets of our UK Plan are invested through third-party fund managers in various investments with underlying holdings which, as of December 31, 2023 and 2022, consisted of: (a) cash and cash equivalents, primarily held as collateral for other financial instruments, (b) debt securities, which include: (i) United Kingdom government debt, (ii) United States, United Kingdom, other European, and emerging market corporate debt, and (iii) real estate debt, and (c) real estate assets, which represent trusts which invest directly or indirectly in various properties throughout the United Kingdom. The following tables set forth the fair value of assets of the UK Plan as of December 31, 2023 and 2022 (in thousands): Assets at Fair Value as of December 31, 2023 Asset Category Level 1 Level 2 Level 3 Total Corporate debt funds $ — $ 44,504 $ — $ 44,504 Government bond funds — 63,934 — 63,934 Cash and cash equivalents 8,797 — — 8,797 Total plan assets in fair value hierarchy $ 8,797 $ 108,438 $ — 117,235 Plan assets measured using NAV as a practical expedient: (1) Debt funds 85,786 Real estate funds 20,056 Total plan assets at fair value $ 223,077 Assets at Fair Value as of December 31, 2022 Asset Category Level 1 Level 2 Level 3 Total Corporate debt funds $ — $ 23,998 $ — $ 23,998 Government bond funds — 45,619 — 45,619 Cash and cash equivalents 19,829 — — 19,829 Total plan assets in fair value hierarchy $ 19,829 $ 69,617 $ — 89,446 Plan assets measured using NAV as a practical expedient: (1) Debt funds 99,990 Real estate funds 20,848 Total plan assets at fair value $ 210,284 _________________ (1) Certain investments measured using net asset value (“NAV”) as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the total fair value of plan assets. NAV is determined by the respective fund manager based on the fair value of the underlying assets held by the fund, less its liabilities, divided by the number of units outstanding. NOTE 14 - RETIREMENT PLANS (Continued) Assets of the UK Plan are allocated within the fair value hierarchy discussed in Note 10 - Fair Value Measurements, based on the nature of the investment. Level 1 assets represent cash and cash equivalents. Level 2 assets consist of corporate debt funds and government bond funds whose underlying investments are valued using observable marketplace inputs. The fair value of the Level 2 assets are generally determined under a market approach using valuation models that incorporate observable inputs such as interest rates, bond yields, and quoted prices. Investments valued using NAV as a practical expedient are excluded from the fair value hierarchy. These investments include: (a) funds which invest predominantly in senior secured debt instruments, targeting diversity across regions and sectors, as well as funds which invest in diversified credit vehicles that seek higher returns than traditional fixed income investments, primarily through U.S. corporate debt, global credit, and other structured debt instruments, and (b) funds which aim to provide long-term income through investment in UK property assets. These investments are redeemable at NAV, which is generally determined on a quarterly basis, and have redemption notice periods of up to 180 days. In addition, certain of these investments are subject to a lockup period of up to 24 months. The methods described above may produce fair values that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes the valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine fair value of certain financial instruments could result in a different fair value measurement at the reporting date. Contributions Our United Kingdom subsidiary expects to contribute approximately $0.6 million to the UK Plan in 2024. Estimated Future Benefit Payments The following estimated benefit payments are expected to be made from the UK Plan in the following years (in thousands): Pension 2024 $ 10,736 2025 $ 11,185 2026 $ 11,689 2027 $ 12,079 2028 $ 12,598 Succeeding five years $ 67,955 Other Retirement Plans We also sponsor three domestic retirement plans in which participation by new individuals is frozen. The aggregate benefit obligation associated with these plans as of December 31, 2023 and 2022 was approximately $6.3 million and $6.7 million, respectively. The estimated fair value of the plan assets as of December 31, 2023 and 2022 was approximately $5.1 million and $4.9 million, respectively. The plan assets are predominantly invested in cash, equity securities, and equity and bond funds, which have quoted market prices in active markets, and as such are considered Level 1 assets within the fair value hierarchy. The liability balances as of December 31, 2023 and 2022 are classified as “Other long-term obligations” in the accompanying Consolidated Balance Sheets. The measurement date for these plans is December 31 of each year. The major assumptions used in the actuarial valuations to determine benefit obligations included discount rates of 4.75% and 5.20% as of December 31, 2023, and approximately 4.80% as of December 31, 2022. In addition, key assumptions included an expected rate of return of 7.00% in order to determine net periodic pension cost for both 2023 and 2022. The net periodic pension cost associated with the domestic plans, as well as the reclassification adjustment from accumulated other comprehensive loss to net periodic pension cost, were insignificant for all periods presented. NOTE 14 - RETIREMENT PLANS (Continued) Defined Contribution Plans We have defined contribution retirement and savings plans that cover eligible employees in the United States. Contributions to these plans are based on a percentage of the employee’s base compensation. The expenses recognized for employer contributions to these plans were approximately $36.7 million for the year ended December 31, 2023, $35.0 million for the year ended December 31, 2022, and $33.0 million for the year ended December 31, 2021. At our discretion and subject to applicable plan documents, we may make additional supplemental matching contributions to one of our defined contribution retirement and savings plans. The expenses recognized related to additional supplemental matching contributions for the years ended December 31, 2023, 2022, and 2021 were approximately $10.2 million, $9.2 million, and $7.7 million, respectively. Our United Kingdom subsidiary also has defined contribution retirement plans. The expenses recognized related to employer matching contributions for the years ended December 31, 2023, 2022, and 2021 were approximately $7.4 million, $7.3 million, and $8.3 million, respectively. Multiemployer Plans We participate in approximately 200 multiemployer pension plans (“MEPPs”) that provide retirement benefits to certain union employees in accordance with various collective bargaining agreements (“CBAs”). As one of many participating employers in an MEPP, we are potentially liable with the other participating employers for any plan underfunding, either through an increase in our required contributions or, in the case of our withdrawal from the plan, a payment based upon our proportionate share of the plan's unfunded benefits, in each case, as described below. Our contributions to a particular MEPP are established by the applicable CBAs; however, our required contributions may increase based on the funded status of an MEPP and legal requirements of the Pension Protection Act of 2006 (the “PPA”), which requires substantially underfunded MEPPs to implement a funding improvement plan (“FIP”) or a rehabilitation plan (“RP”) to improve their funded status. Factors that could impact the funded status of an MEPP include, without limitation, investment performance, changes in the participant demographics, decline in the number of contributing employers, changes in actuarial assumptions, and the utilization of extended amortization provisions. An FIP or RP requires a particular MEPP to adopt measures to correct its underfunding status. These measures may include, but are not limited to: (a) an increase in our contribution rate as a signatory to the applicable CBA, (b) a reallocation of the contributions already being made by participating employers for various benefits to individuals participating in the MEPP, and/or (c) a reduction in the benefits to be paid to future and/or current retirees. In addition, the PPA requires that a 5% surcharge be levied on employer contributions for the first year commencing after the date the employer receives notice that the MEPP is in critical status and a 10% surcharge on each succeeding year until a CBA is in place with terms and conditions consistent with the RP. We could also be obligated to make payments to MEPPs if we either cease to have an obligation to contribute to the MEPP or significantly reduce our contributions to the MEPP because we reduce our number of employees who are covered by the relevant MEPP for various reasons, including, but not limited to, layoffs or closure of a subsidiary assuming the MEPP has unfunded vested benefits. The amount of such payments (known as a complete or partial withdrawal liability) would equal our proportionate share of the MEPPs’ unfunded vested benefits. We believe that certain of the MEPPs in which we participate may have unfunded vested benefits. Due to uncertainty regarding future factors that could trigger withdrawal liability, as well as the absence of specific information regarding the MEPP’s current financial situation, we are unable to determine: (a) the amount and timing of a future withdrawal liability, if any, and (b) whether our participation in these MEPPs could have a material adverse impact on our financial position, results of operations, or liquidity. We did not record any material withdrawal liabilities for the years ended December 31, 2023, 2022, and 2021. NOTE 14 - RETIREMENT PLANS (Continued) The following table lists all MEPPs to which our contributions exceeded $2.0 million in 2023. This table also lists all MEPPs to which we contributed in 2023 in excess of $0.5 million for MEPPs in the critical status, “red zone,” and $1.0 million for MEPPs in the endangered status, “orange or yellow zones,” as defined by the PPA (in thousands): Pension Fund EIN/Pension Plan Number PPA Zone Status (1) FIP/RP Contributions Contributions greater than 5% of total plan contributions (2) Expiration 2023 2022 2023 2022 2021 National Automatic Sprinkler Industry Pension Fund 52-6054620 001 Green Green NA $ 25,559 $ 21,583 $ 20,987 Yes March 2024 to July 2027 National Electrical Benefit Fund 53-0181657 001 Green Green NA 18,128 15,192 12,310 Yes February 2024 to November 2027 United Association National Pension Fund 52-6152779 001 Green Green NA 16,815 15,288 14,723 No January 2024 to May 2029 Sheet Metal Workers National Pension Fund 52-6112463 001 Green Green NA 10,797 9,505 10,307 No April 2024 to July 2028 Central Pension Fund of the IUOE & Participating Employers 36-6052390 001 Green Green NA 8,573 7,651 6,627 No January 2024 to December 2026 Electrical Workers Local No. 26 Pension Trust Fund 52-6117919 001 Green Green NA 8,283 7,844 9,346 Yes May 2024 to September 2027 Pension, Hospitalization & Benefit Plan of the Electrical Industry-Pension Trust Account 13-6123601 001 Green Green NA 7,198 8,122 7,355 No January 2025 to April 2025 Plumbers Pipefitters & Mechanical Equipment Service Local Union 392 Pension Plan 31-0655223 001 Red Red Implemented 7,010 7,674 7,110 Yes May 2024 to May 2025 Electrical Workers Pension Plan Local 103 IBEW 04-6063734 001 Green Green NA 6,537 2,900 — Yes August 2028 Northern California Pipe Trades Pension Plan 94-3190386 001 Green Green NA 6,317 3,238 2,663 No June 2024 to July 2024 Edison Pension Plan 93-6061681 001 Green Green NA 5,840 5,325 4,229 Yes December 2024 Sheet Metal Workers Pension Plan of Northern California 51-6115939 001 Red Red Implemented 5,738 6,074 7,850 Yes June 2024 to June 2026 San Diego Electrical Pension Plan 95-6101801 001 Green Green NA 5,511 4,258 4,068 Yes May 2024 Heating, Piping & Refrigeration Pension Fund 52-1058013 001 Green Green NA 5,315 4,625 5,591 Yes July 2024 to July 2025 Pipefitters Union Local 537 Pension Fund 51-6030859 001 Green Green NA 5,179 5,039 5,922 Yes August 2025 Southern California Pipe Trades Retirement Fund 51-6108443 001 Green Green NA 4,657 4,650 6,272 Yes August 2024 to August 2026 Electrical Contractors Association of the City of Chicago Local Union 134, IBEW Joint Pension Trust of Chicago Pension Plan 2 51-6030753 002 Green Green NA 4,432 3,516 4,225 No June 2024 to December 2024 IBEW Local 701 Pension Fund 36-6455509 001 Green Green NA 3,989 2,625 1,276 No May 2024 to September 2024 Eighth District Electrical Pension Fund 84-6100393 001 Green Green NA 3,844 3,339 3,298 Yes February 2024 to February 2027 Southern California IBEW-NECA Pension Trust Fund 95-6392774 001 Yellow Yellow Implemented 3,801 4,287 4,876 No May 2024 to November 2026 IBEW Local No. 82 Pension Plan 31-6127268 001 Green Green NA 3,701 2,549 956 Yes December 2026 Sheet Metal Workers Pension Plan of Southern California, Arizona & Nevada 95-6052257 001 Green Green NA 3,399 2,921 3,322 No June 2024 to July 2028 Kern County Electrical Workers Pension Fund 95-6123049 001 Green Green NA 3,299 1,542 1,167 Yes November 2027 NOTE 14 - RETIREMENT PLANS (Continued) Pension Fund EIN/Pension Plan Number PPA Zone Status (1) FIP/RP Contributions Contributions greater than 5% of total plan contributions (2) Expiration 2023 2022 2023 2022 2021 U.A. Local 393 Pension Trust Fund Defined Benefit 94-6359772 002 Green Green NA 3,263 3,517 3,507 Yes June 2024 to July 2024 Arizona Pipe Trades Pension Trust Fund 86-6025734 001 Green Green NA 3,048 2,940 2,020 Yes June 2024 Joint Pension Fund of Local Union No. 102 22-1615726 001 Green Green NA 2,868 1,762 1,531 Yes June 2024 Plumbers & Steamfitters Local 486 Pension Fund 52-6124449 001 Green Green NA 2,828 1,599 1,351 Yes December 2025 Plumbers & Pipefitters Local No. 189 Pension Fund 31-0894807 001 Green Green NA 2,557 1,272 596 Yes May 2024 to June 2025 Local No. 697 IBEW and Electrical Industry Pension Fund 51-6133048 001 Green Green NA 2,528 2,287 1,753 Yes May 2024 U.A. Plumbers Local 24 Pension Fund 22-6042823 001 Green Green NA 2,295 1,819 2,270 Yes April 2025 NECA-IBEW Pension Trust Fund 51-6029903 001 Green Green NA 2,228 3,034 2,491 No May 2024 to December 2024 IBEW 332 Pension Fund - Part A 94-2688032 004 Green Green NA 2,062 4,177 2,339 Yes May 2024 to June 2024 Plumbers & Pipefitters Local 162 Pension Fund 31-6125999 001 Yellow Yellow Implemented 1,243 1,132 1,034 Yes May 2024 to May 2026 Steamfitters Local Union No. 420 Pension Plan 23-2004424 001 Red Red Implemented 1,227 1,018 677 No April 2026 to May 2026 Boilermaker-Blacksmith National Pension Trust 48-6168020 001 Red Green Implemented 1,140 6,434 3,479 Yes April 2025 to September 2026 Plumbing & Pipe Fitting Local 219 Pension Fund 34-6682376 001 Red Red Implemented 919 1,172 1,167 Yes May 2026 Carpenters Pension Trust Fund for Northern California 94-6050970 001 Red Red Implemented 610 532 568 No June 2027 Other Multiemployer Pension Plans 56,091 53,723 51,818 Various Total Contributions $ 258,829 $ 236,165 $ 221,081 _________________ (1) The zone status represents the most recent available information for the respective MEPP, which may be from 2022 or earlier for the 2023 year and from 2021 or earlier for the 2022 year. In general, plans with a “green” zone status have a funding ratio of at least 80%, plans with an “orange” or “yellow” zone status have a funding ratio of between 65% and less than 80%, and plans with a “red” zone status are less than 65% funded or are projected to have a funding deficiency in any of the next ten years. (2) This information was obtained from the respective plan’s Form 5500 (“Forms”) for the most current available filing. These dates may not correspond with our fiscal year contributions. The percentages of contributions are based upon disclosures contained in the plans’ Forms. Those Forms, among other things, disclose the names of individual participating employers whose annual contributions account for more than 5% of the aggregate annual amount contributed by all participating employers for a plan year. Accordingly, if the annual contribution of two or more of our subsidiaries each accounted for less than 5% of such contributions, but in the aggregate accounted for in excess of 5% of such contributions, that greater percentage is not available and therefore is not disclosed. The nature and diversity of our operations may result in volatility in the amount of our contributions to a particular MEPP for any given period. That is because, in any given market, a change in the mix, volume of, or size of our projects could result in a change in our direct labor force and a corresponding change in our contributions to the MEPP(s) dictated by the applicable CBA. Additionally, the amount of contributions to a particular MEPP could also be affected by the terms of the CBA, which could require at a particular time, an increase in the contribution rate and/or surcharges. Acquisitions made by us since 2021 have resulted in incremental contributions to various MEPPs of approximately $8.0 million.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Severance Agreements We have agreements with our executive officers and certain other key management personnel providing for severance benefits for such employees upon termination of their employment under certain circumstances. Guarantees In the ordinary course of business, we, at times, guarantee obligations of our subsidiaries under certain contracts. Generally, we are liable under such an arrangement only if our subsidiary fails to perform its obligations under the contract. Historically, we have not incurred any substantial liabilities as a consequence of these guarantees. Surety Bonds The terms of our construction contracts frequently require that we obtain from surety companies, and provide to our customers, surety bonds as a condition to the award of such contracts. These surety bonds are issued in return for premiums, which vary depending on the size and type of the bond, and secure our payment and performance obligations under such contracts. We have agreed to indemnify the surety companies for amounts, if any, paid by them in respect of surety bonds issued on our behalf. As of December 31, 2023, based on the percentage-of-completion of our projects covered by surety bonds, our aggregate estimated exposure, assuming defaults on all our then existing contractual obligations, was approximately $2.2 billion, which represents approximately 25% of our total remaining performance obligations. Surety bonds are sometimes provided to secure obligations for wages and benefits payable to or for certain of our employees, at the request of labor unions representing such employees. In addition, surety bonds may be issued as collateral for certain insurance obligations. As of December 31, 2023, we satisfied approximately $48.1 million of the collateral requirements of our insurance programs by utilizing surety bonds. We are not aware of any losses in connection with surety bonds that have been posted on our behalf, and we do not expect to incur significant losses in the foreseeable future. Hazardous Materials We are subject to regulation with respect to the handling or disposal of certain materials used in the performance of our services, which are classified as hazardous or toxic by federal, state, and local agencies. Our practice is to avoid participation in projects principally involving the remediation or removal of such materials. However, when remediation is required as part of our contract performance, we believe we comply with all applicable regulations governing the discharge of hazardous materials into the environment or otherwise relating to the protection of the environment. Collective Bargaining Agreements At December 31, 2023, we employed approximately 38,300 people, approximately 60% of whom are represented by various unions pursuant to nearly 450 collective bargaining agreements between our individual subsidiaries or trade associations and local unions, as well as two collective bargaining agreements that are national or regional in scope. We believe that our relations with our labor unions are generally positive. Government Contracts When we perform work as a federal government contractor/subcontractor or when we perform work on a project that has received federal government funding, we are subject to U.S. government audits and investigations relating to our operations, which such audits may result in fines, penalties and compensatory and treble damages, and possible suspension or debarment from doing business with the government. Based on currently available information, we believe the outcome of ongoing government disputes and investigations will not have a material impact on our financial position, results of operations, or liquidity. Legal Proceedings We are involved in several legal proceedings in which damages and claims have been asserted against us. We believe that we have a number of valid defenses to such proceedings and claims and intend to vigorously defend ourselves. We do not believe that any such matters will have a material adverse effect on our financial position, results of operations, or liquidity. We record a loss contingency if the potential loss from a proceeding or claim is considered probable and the amount can be reasonably estimated or a range of loss can be determined. We provide disclosure when it is reasonably possible that a loss will be incurred in excess of any recorded provision. Significant judgment is required in these determinations. As additional information becomes available, we reassess prior determinations and may change our estimates. Additional claims may be asserted against us in the future. Litigation is subject to many uncertainties, and the outcome of litigation is not predictable with assurance. It is possible that a litigation matter for which liabilities have not been recorded could be decided unfavorably to us, and that any such unfavorable decision could have a material adverse effect on our financial position, results of operations, or liquidity.

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2023
Leases [Abstract]
Lessee, Operating Leases	LEASES We lease real estate, vehicles, and equipment under various arrangements which are classified as either operating or finance leases. A lease exists when a contract or part of a contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In determining whether a lease exists, we consider whether a contract provides us with both: (a) the right to obtain substantially all of the economic benefits from the use of the identified asset and (b) the right to direct the use of the identified asset. Many of our leases include base rental periods coupled with options to renew or terminate the lease, generally at our discretion. Certain leases additionally include options to purchase the leased asset. In evaluating the lease term, we consider whether we are reasonably certain to exercise such options. To the extent a significant economic incentive exists to exercise an option, that option is included within the lease term. However, based on the nature of our lease arrangements, options generally do not provide us with a significant economic incentive and are therefore excluded from the lease term for the majority of our arrangements. Our leases typically include a combination of fixed and variable payments. Fixed payments are generally included when measuring the right-of-use asset and lease liability. Variable payments, which primarily represent payments based on usage of the underlying asset, are generally excluded from such measurement and expensed as incurred. In addition, certain of our lease arrangements may contain a lease coupled with an arrangement to provide other services, such as maintenance, or may require us to make other payments on behalf of the lessor related to the leased asset, such as payments for taxes or insurance. We account for these non-lease components together with the associated lease component for each of our asset classes. The measurement of right-of-use assets and lease liabilities requires us to estimate appropriate discount rates. To the extent the rate implicit in the lease is readily determinable, such rate is utilized. However, based on information available at lease commencement for the majority of our leases, the rate implicit in the lease is not known. In these instances, we utilize an incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. Our lease arrangements generally do not contain significant restrictions or covenants; however, certain of our vehicle and equipment leases include residual value guarantees, whereby we provide a guarantee to the lessor that the value of the underlying asset will be at least a specified amount at the end of the lease. Amounts probable of being owed under these guarantees are included within the measurement of the right-of-use asset and lease liability. Lease Position The following table presents our lease-related assets and liabilities as of December 31, 2023 and 2022 (in thousands): Classification on the Consolidated Balance Sheet December 31, December 31, Assets Operating lease assets Operating lease right-of-use assets $ 310,498 $ 268,063 Finance lease assets Property, plant, and equipment, net 4,932 6,117 Total lease assets $ 315,430 $ 274,180 Liabilities Current Operating Operating lease liabilities, current $ 75,236 $ 67,218 Finance Current maturities of long-term debt and finance lease liabilities 2,465 2,652 Noncurrent Operating Operating lease liabilities, long-term 259,430 220,764 Finance Long-term debt and finance lease liabilities 2,838 3,807 Total lease liabilities $ 339,969 $ 294,441 NOTE 16 - LEASES (Continued) Lease Costs The following table presents information related to our lease expense for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Finance lease expense: Amortization expense $ 2,816 $ 3,550 $ 4,255 Interest expense 175 178 255 Operating lease expense 93,158 77,143 70,928 Short-term lease expense (1) 224,047 185,061 150,500 Variable lease expense 9,482 6,782 5,421 Total lease expense $ 329,678 $ 272,714 $ 231,359 _________________ (1) Short-term lease expense includes both leases and rentals with initial terms of one year or less and predominantly represents equipment used on construction projects. Sublease rental income was approximately $6.7 million, $3.8 million, and $0.2 million for the years ended December 31, 2023, 2022, and 2021, respectively. Lease Term and Discount Rate The following table presents certain information related to the lease terms and discount rates for our leases as of December 31, 2023 and 2022: December 31, December 31, Weighted-average remaining lease term: Operating leases 5.7 years 5.9 years Finance leases 2.9 years 2.9 years Weighted-average discount rate: Operating leases 4.11 % 3.45 % Finance leases 3.57 % 2.85 % Other Information The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 90,412 $ 74,927 $ 69,797 Operating cash flows used for finance leases $ 175 $ 178 $ 255 Financing cash flows used for finance leases $ 2,776 $ 3,551 $ 4,189 Right-of-use assets obtained in exchange for new operating lease liabilities $ 125,417 $ 75,027 $ 80,661 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,427 $ 2,209 $ 2,301 NOTE 16 - LEASES (Continued) Maturity of Lease Liabilities The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2023 (in thousands): Operating Leases Finance Leases 2024 $ 87,058 $ 2,605 2025 69,127 1,533 2026 60,558 782 2027 47,961 389 2028 36,858 222 Thereafter 74,510 64 Total minimum lease payments 376,072 5,595 Less: Amount of lease payments representing interest (41,406) (292) Present value of future minimum lease payments $ 334,666 $ 5,303 Current portion of lease liabilities $ 75,236 $ 2,465 Noncurrent portion of lease liabilities 259,430 2,838 Present value of future minimum lease payments $ 334,666 $ 5,303
Leasee, Finance Leases	LEASES We lease real estate, vehicles, and equipment under various arrangements which are classified as either operating or finance leases. A lease exists when a contract or part of a contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In determining whether a lease exists, we consider whether a contract provides us with both: (a) the right to obtain substantially all of the economic benefits from the use of the identified asset and (b) the right to direct the use of the identified asset. Many of our leases include base rental periods coupled with options to renew or terminate the lease, generally at our discretion. Certain leases additionally include options to purchase the leased asset. In evaluating the lease term, we consider whether we are reasonably certain to exercise such options. To the extent a significant economic incentive exists to exercise an option, that option is included within the lease term. However, based on the nature of our lease arrangements, options generally do not provide us with a significant economic incentive and are therefore excluded from the lease term for the majority of our arrangements. Our leases typically include a combination of fixed and variable payments. Fixed payments are generally included when measuring the right-of-use asset and lease liability. Variable payments, which primarily represent payments based on usage of the underlying asset, are generally excluded from such measurement and expensed as incurred. In addition, certain of our lease arrangements may contain a lease coupled with an arrangement to provide other services, such as maintenance, or may require us to make other payments on behalf of the lessor related to the leased asset, such as payments for taxes or insurance. We account for these non-lease components together with the associated lease component for each of our asset classes. The measurement of right-of-use assets and lease liabilities requires us to estimate appropriate discount rates. To the extent the rate implicit in the lease is readily determinable, such rate is utilized. However, based on information available at lease commencement for the majority of our leases, the rate implicit in the lease is not known. In these instances, we utilize an incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. Our lease arrangements generally do not contain significant restrictions or covenants; however, certain of our vehicle and equipment leases include residual value guarantees, whereby we provide a guarantee to the lessor that the value of the underlying asset will be at least a specified amount at the end of the lease. Amounts probable of being owed under these guarantees are included within the measurement of the right-of-use asset and lease liability. Lease Position The following table presents our lease-related assets and liabilities as of December 31, 2023 and 2022 (in thousands): Classification on the Consolidated Balance Sheet December 31, December 31, Assets Operating lease assets Operating lease right-of-use assets $ 310,498 $ 268,063 Finance lease assets Property, plant, and equipment, net 4,932 6,117 Total lease assets $ 315,430 $ 274,180 Liabilities Current Operating Operating lease liabilities, current $ 75,236 $ 67,218 Finance Current maturities of long-term debt and finance lease liabilities 2,465 2,652 Noncurrent Operating Operating lease liabilities, long-term 259,430 220,764 Finance Long-term debt and finance lease liabilities 2,838 3,807 Total lease liabilities $ 339,969 $ 294,441 NOTE 16 - LEASES (Continued) Lease Costs The following table presents information related to our lease expense for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Finance lease expense: Amortization expense $ 2,816 $ 3,550 $ 4,255 Interest expense 175 178 255 Operating lease expense 93,158 77,143 70,928 Short-term lease expense (1) 224,047 185,061 150,500 Variable lease expense 9,482 6,782 5,421 Total lease expense $ 329,678 $ 272,714 $ 231,359 _________________ (1) Short-term lease expense includes both leases and rentals with initial terms of one year or less and predominantly represents equipment used on construction projects. Sublease rental income was approximately $6.7 million, $3.8 million, and $0.2 million for the years ended December 31, 2023, 2022, and 2021, respectively. Lease Term and Discount Rate The following table presents certain information related to the lease terms and discount rates for our leases as of December 31, 2023 and 2022: December 31, December 31, Weighted-average remaining lease term: Operating leases 5.7 years 5.9 years Finance leases 2.9 years 2.9 years Weighted-average discount rate: Operating leases 4.11 % 3.45 % Finance leases 3.57 % 2.85 % Other Information The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 90,412 $ 74,927 $ 69,797 Operating cash flows used for finance leases $ 175 $ 178 $ 255 Financing cash flows used for finance leases $ 2,776 $ 3,551 $ 4,189 Right-of-use assets obtained in exchange for new operating lease liabilities $ 125,417 $ 75,027 $ 80,661 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,427 $ 2,209 $ 2,301 NOTE 16 - LEASES (Continued) Maturity of Lease Liabilities The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2023 (in thousands): Operating Leases Finance Leases 2024 $ 87,058 $ 2,605 2025 69,127 1,533 2026 60,558 782 2027 47,961 389 2028 36,858 222 Thereafter 74,510 64 Total minimum lease payments 376,072 5,595 Less: Amount of lease payments representing interest (41,406) (292) Present value of future minimum lease payments $ 334,666 $ 5,303 Current portion of lease liabilities $ 75,236 $ 2,465 Noncurrent portion of lease liabilities 259,430 2,838 Present value of future minimum lease payments $ 334,666 $ 5,303

Additional Cash Flow Informatio

Additional Cash Flow Information	12 Months Ended
Additional Cash Flow Information	Dec. 31, 2023
Supplemental Cash Flow Information [Abstract]
Additional Cash Flow Information	ADDITIONAL CASH FLOW INFORMATION The following table presents information about cash paid for interest and income taxes for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Cash paid during the year for: Interest $ 16,246 $ 11,653 $ 5,259 Income taxes $ 230,496 $ 168,732 $ 130,811

Segment Information

Segment Information	12 Months Ended
Segment Information	Dec. 31, 2023
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We are one of the largest specialty contractors in the United States and a leading provider of electrical and mechanical construction and facilities services, building services, and industrial services. Our services are provided to a broad range of commercial, technology, manufacturing, industrial, healthcare, utility, and institutional customers through approximately 100 operating subsidiaries. Such operating subsidiaries are organized into the following reportable segments: • United States electrical construction and facilities services; • United States mechanical construction and facilities services; • United States building services; • United States industrial services; and • United Kingdom building services. Our reportable segments and related disclosures reflect certain reclassifications of prior year amounts from our United States mechanical construction and facilities services segment to our United States building services segment due to changes in our internal reporting structure aimed at realigning our service offerings. NOTE 18 - SEGMENT INFORMATION (Continued) The following tables present financial information for each of our reportable segments for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Revenues from unrelated entities: United States electrical construction and facilities services $ 2,783,723 $ 2,433,114 $ 2,029,893 United States mechanical construction and facilities services 5,074,803 4,292,208 3,922,200 United States building services 3,120,134 2,754,953 2,455,129 United States industrial services 1,167,790 1,118,767 986,407 Total United States operations 12,146,450 10,599,042 9,393,629 United Kingdom building services 436,423 477,078 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580 2023 2022 2021 Total revenues: United States electrical construction and facilities services $ 2,786,895 $ 2,438,916 $ 2,033,863 United States mechanical construction and facilities services 5,134,686 4,338,584 3,935,737 United States building services 3,228,056 2,856,115 2,553,566 United States industrial services 1,179,321 1,175,469 1,021,217 Less intersegment revenues (182,508) (210,042) (150,754) Total United States operations 12,146,450 10,599,042 9,393,629 United Kingdom building services 436,423 477,078 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580 2023 2022 2021 Operating income (loss): United States electrical construction and facilities services $ 230,640 $ 148,728 $ 169,355 United States mechanical construction and facilities services 530,644 330,325 312,809 United States building services 182,995 146,639 124,335 United States industrial services 35,375 19,787 (1,666) Total United States operations 979,654 645,479 604,833 United Kingdom building services 25,681 29,838 27,998 Corporate administration (127,229) (110,440) (102,031) Impairment loss on long-lived assets (2,350) — — Total operations 875,756 564,877 530,800 Other items: Net periodic pension (cost) income (1,119) 4,311 3,625 Interest expense (17,199) (13,199) (6,071) Interest income 15,415 2,761 949 Income before income taxes $ 872,853 $ 558,750 $ 529,303 NOTE 18 - SEGMENT INFORMATION (Continued) 2023 2022 2021 Capital expenditures: United States electrical construction and facilities services $ 6,929 $ 11,228 $ 4,985 United States mechanical construction and facilities services 37,543 11,930 10,108 United States building services 19,843 13,303 11,539 United States industrial services 10,433 9,905 6,159 Total United States operations 74,748 46,366 32,791 United Kingdom building services 1,984 2,816 3,015 Corporate administration 1,672 107 386 Total operations $ 78,404 $ 49,289 $ 36,192 2023 2022 2021 Depreciation and amortization of property, plant, and equipment: United States electrical construction and facilities services $ 8,402 $ 7,543 $ 7,229 United States mechanical construction and facilities services 12,503 11,492 11,354 United States building services 15,672 12,964 12,090 United States industrial services 11,146 10,888 11,723 Total United States operations 47,723 42,887 42,396 United Kingdom building services 3,116 2,752 3,938 Corporate administration 983 1,657 2,013 Total operations $ 51,822 $ 47,296 $ 48,347 December 31, 2023 December 31, 2022 December 31, 2021 Contract assets: United States electrical construction and facilities services $ 73,464 $ 75,603 $ 48,382 United States mechanical construction and facilities services 97,252 99,632 89,102 United States building services 61,867 56,694 42,818 United States industrial services 17,129 10,727 18,992 Total United States operations 249,712 242,656 199,294 United Kingdom building services 20,173 30,520 30,849 Total operations $ 269,885 $ 273,176 $ 230,143 December 31, 2023 December 31, 2022 December 31, 2021 Contract liabilities: United States electrical construction and facilities services $ 399,550 $ 271,161 $ 200,966 United States mechanical construction and facilities services 925,481 594,453 386,518 United States building services 223,202 184,821 150,333 United States industrial services 17,366 17,746 16,481 Total United States operations 1,565,599 1,068,181 754,298 United Kingdom building services 29,510 30,082 33,836 Total operations $ 1,595,109 $ 1,098,263 $ 788,134 NOTE 18 - SEGMENT INFORMATION (Continued) December 31, 2023 December 31, 2022 December 31, 2021 Long-lived assets: United States electrical construction and facilities services $ 290,896 $ 302,448 $ 237,766 United States mechanical construction and facilities services 526,567 517,649 514,065 United States building services 574,917 497,892 500,368 United States industrial services 318,077 341,646 365,563 Total United States operations 1,710,457 1,659,635 1,617,762 United Kingdom building services 9,761 10,320 11,402 Corporate administration 1,741 990 2,535 Total operations $ 1,721,959 $ 1,670,945 $ 1,631,699 December 31, 2023 December 31, 2022 December 31, 2021 Total assets: United States electrical construction and facilities services $ 1,243,707 $ 1,078,405 $ 855,417 United States mechanical construction and facilities services 2,242,833 1,835,001 1,664,822 United States building services 1,382,664 1,206,518 1,097,568 United States industrial services 571,658 552,545 589,017 Total United States operations 5,440,862 4,672,469 4,206,824 United Kingdom building services 277,066 255,547 241,740 Corporate administration 891,793 596,591 992,882 Total operations $ 6,609,721 $ 5,524,607 $ 5,441,446

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENTS Subsequent to December 31, 2023, we entered into definitive agreements to acquire three companies for upfront consideration of approximately $137.0 million. These transactions are expected to close in the second quarter of 2024, subject to customary closing conditions. These acquisitions are comprised of: (a) two companies that will be included within our United States mechanical construction and facilities services segment including: (i) a leading plumbing services provider in the Southeast region of the United States and (ii) a full service provider of mechanical construction and maintenance services in Central Texas, and (b) a company which provides building automation and controls solutions in the Northeast region of the United States, that will be included in our United States building services segment.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
Schedule II - Valuation and Qualifying Accounts	Dec. 31, 2023
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure	Description Balance at Beginning of Year Costs and Deductions (1) Balance at Allowance for credit losses Year Ended December 31, 2023 $ 22,382 7,859 (7,739) $ 22,502 Year Ended December 31, 2022 $ 23,534 5,166 (6,318) $ 22,382 Year Ended December 31, 2021 $ 18,031 8,041 (2,538) $ 23,534 _________________

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net income attributable to EMCOR Group, Inc. (in US dollars)	$ 632,994	$ 406,122	$ 383,532

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2023
Accounting Policies [Abstract]
Fair Value Measurements	For disclosure purposes, we utilize a fair value hierarchy to categorize qualifying assets and liabilities into three broad levels based on the priority of the inputs used to determine their fair values. The hierarchy, which gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities and the lowest priority to unobservable inputs, is comprised of the following three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets and liabilities. Level 2 – Observable inputs, other than Level 1 inputs, that are directly or indirectly observable for the asset or liability, including quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Significant unobservable inputs that reflect the reporting entity’s own assumptions.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and the subsidiaries and joint ventures it controls. All intercompany accounts and transactions have been eliminated. Investments over which we exercise significant influence, but do not control, are accounted for using the equity method of accounting. For joint ventures that have been accounted for using the consolidation method of accounting, noncontrolling interests represent the allocation of earnings to our joint venture partners who either have a minority-ownership interest in the joint venture or are not the primary beneficiary of the joint venture.
Principles of Preparation	Principles of Preparation The preparation of the consolidated financial statements, in conformity with accounting principles generally accepted in the United States, requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could materially differ from those estimates. Our reportable segments and related disclosures reflect certain reclassifications of prior year amounts from our United States mechanical construction and facilities services segment to our United States building services segment due to changes in our internal reporting structure aimed at realigning our service offerings.
Revenue Recognition	Revenue Recognition Revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. Refer to Note 3 - Revenue from Contracts with Customers of the notes to consolidated financial statements for additional information. The Company recognizes revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services by applying the following five step model: (1) Identify the contract with a customer A contract with a customer exists when: (a) the parties have approved the contract and are committed to perform their respective obligations, (b) the rights of the parties can be identified, (c) payment terms can be identified, (d) the arrangement has commercial substance, and (e) collectability of consideration is probable. Judgment is required when determining if the contractual criteria are met, specifically in the earlier stages of a project when a formally executed contract may not yet exist. In these situations, the Company evaluates all relevant facts and circumstances, including the existence of other forms of documentation or historical experience with our customers that may indicate a contractual agreement is in place and revenue should be recognized. In determining if the collectability of consideration is probable, the Company considers the customer’s ability and intention to pay such consideration through an evaluation of several factors, including an assessment of the creditworthiness of the customer and our prior collection history with such customer. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) (2) Identify the performance obligations in the contract At contract inception, the Company assesses the goods or services promised in a contract and identifies, as a separate performance obligation, each distinct promise to transfer goods or services to the customer. The identified performance obligations represent the “unit of account” for purposes of determining revenue recognition. In order to properly identify separate performance obligations, the Company applies judgment in determining whether each good or service provided is: (a) capable of being distinct, whereby the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and (b) distinct within the context of the contract, whereby the transfer of the good or service to the customer is separately identifiable from other promises in the contract. In addition, when assessing performance obligations within a contract, the Company considers the warranty provisions included within such contract. To the extent the warranty terms provide the customer with an additional service, other than assurance that the promised good or service complies with agreed upon specifications, such warranty is accounted for as a separate performance obligation. In determining whether a warranty provides an additional service, the Company considers each warranty provision in comparison to warranty terms which are standard in the industry. Our contracts are often modified through change orders to account for changes in the scope and price of the goods or services we are providing. Although the Company evaluates each change order to determine whether such modification creates a separate performance obligation, the majority of our change orders are for goods or services that are not distinct within the context of our original contract and, therefore, are not treated as separate performance obligations. (3) Determine the transaction price The transaction price represents the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to our customers. The consideration promised within a contract may include fixed amounts, variable amounts, or both. To the extent the performance obligation includes variable consideration, including contract bonuses and penalties that can either increase or decrease the transaction price, the Company estimates the amount of variable consideration to be included in the transaction price utilizing one of two prescribed methods, depending on which method better predicts the amount of consideration to which the entity will be entitled. Such methods include: (a) the expected value method, whereby the amount of variable consideration to be recognized represents the sum of probability-weighted amounts in a range of possible consideration amounts, and (b) the most likely amount method, whereby the amount of variable consideration to be recognized represents the single most likely amount in a range of possible consideration amounts. When applying these methods, the Company considers all information that is reasonably available, including historical, current, and estimates of future performance. The expected value method is typically utilized in situations where a contract contains a large number of possible outcomes while the most likely amount method is typically utilized in situations where a contract has only two possible outcomes. Variable consideration is included in the transaction price only to the extent it is probable, in the Company’s judgment, that a significant future reversal in the amount of cumulative revenue recognized under the contract will not occur when the uncertainty associated with the variable consideration is subsequently resolved. This threshold is referred to as the variable consideration constraint. In assessing whether to apply the variable consideration constraint, the Company considers if factors exist that could increase the likelihood or the magnitude of a potential reversal of revenue, including, but not limited to, whether: (a) the amount of consideration is highly susceptible to factors outside of the Company’s influence, such as the actions of third parties, (b) the uncertainty surrounding the amount of consideration is not expected to be resolved for a long period of time, (c) the Company’s experience with similar types of contracts is limited or that experience has limited predictive value, (d) the Company has a practice of either offering a broad range of price concessions or changing the payment terms and conditions of similar contracts in similar circumstances, and (e) the contract has a large number and broad range of possible consideration amounts. Pending change orders represent one of the most common forms of variable consideration included within contract value and typically 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. In estimating the transaction price for pending change orders, the Company considers all relevant facts, including documented correspondence with the customer regarding acknowledgment of and/or agreement with the modification, as well as historical experience with the customer or similar contractual circumstances. Based upon this assessment, the Company estimates the transaction price, including whether the variable consideration constraint should be applied. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) Contract claims are another form of variable consideration which is common within our industry. Claim amounts represent revenue that has been recognized for contract modifications that are not submitted or are in dispute as to both scope and price. In estimating the transaction price for claims, the Company considers all relevant facts available. However, given the uncertainty surrounding claims, including the potential long-term nature of dispute resolution and the broad range of possible consideration amounts, there is an increased likelihood that any additional contract revenue associated with contract claims is constrained. The resolution of claims involves negotiations and, in certain cases, litigation. In the event litigation costs are incurred by us in connection with claims, such litigation costs are expensed as incurred, although we may seek to recover these costs. For some transactions, the receipt of consideration does not match the timing of the transfer of goods or services to the customer. For such contracts, the Company evaluates whether this timing difference represents a financing arrangement within the contract. Although rare, if a contract is determined to contain a significant financing component, the Company adjusts the promised amount of consideration for the effects of the time value of money when determining the transaction price of such contract. Although our customers may retain a portion of the contract price until completion of the project and final contract settlement, these retainage amounts are not considered a significant financing component as the intent of the withheld amounts is to provide the customer with assurance that we will complete our obligations under the contract rather than to provide financing to the customer. In addition, although we may be entitled to advanced payments from our customers on certain contracts, these advanced payments generally do not represent a significant financing component as the payments are used to meet working capital demands that can be higher in the early stages of a contract, as well as to protect us from our customer failing to meet its obligations under the contract. Changes in the estimates of transaction prices are recognized on a cumulative catch-up basis in the period in which the revisions to the estimates are made. Such changes in estimates can result in the recognition of revenue in a current period for performance obligations which were satisfied or partially satisfied in prior periods. Such changes in estimates may also result in the reversal of previously recognized revenue if the ultimate outcome differs from the Company’s previous estimate. (4) Allocate the transaction price to the performance obligations in the contract For contracts that contain multiple performance obligations, the Company allocates the transaction price to each performance obligation based on a relative standalone selling price. The Company determines the standalone selling price based on the price at which the performance obligation would have been sold separately in similar circumstances to similar customers. If the standalone selling price is not observable, the Company estimates the standalone selling price taking into account all available information such as market conditions and internal pricing guidelines. In certain circumstances, the standalone selling price is determined using an expected profit margin on anticipated costs related to the performance obligation. (5) Recognize revenue as performance obligations are satisfied The Company recognizes revenue at the time the related performance obligation is satisfied by transferring a promised good or service to its customers. A good or service is considered to be transferred when the customer obtains control. The Company can transfer control of a good or service and satisfy its performance obligations either over time or at a point in time. The Company transfers control of a good or service over time and, therefore, satisfies a performance obligation and recognizes revenue over time if one of the following three criteria are met: (a) the customer simultaneously receives and consumes the benefits provided by the Company’s performance as we perform, (b) the Company’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or (c) the Company’s performance does not create an asset with an alternative use to us, and we have an enforceable right to payment for performance completed to date. For our performance obligations satisfied over time, we recognize revenue by measuring the progress toward complete satisfaction of that performance obligation. The selection of the method to measure progress towards completion can be either an input method or an output method and requires judgment based on the nature of the goods or services to be provided. For our construction contracts, revenue is generally recognized over time as our performance creates or enhances an asset that the customer controls as it is created or enhanced. Our fixed price construction projects generally use a cost-to-cost input method to measure our progress towards complete satisfaction of the performance obligation as we believe it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost measure of progress, 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. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) For our unit price construction contracts, progress towards complete satisfaction is measured through an output method, such as the number of units produced or delivered, when our performance does not produce significant amounts of work in process or finished goods prior to complete satisfaction of such performance obligations. For our services contracts, revenue is also generally recognized over time as the customer simultaneously receives and consumes the benefits of our performance as we perform the service. For our fixed price service contracts with specified service periods, revenue is generally recognized on a straight-line basis over such service period when our inputs are expended evenly and the customer receives and consumes the benefits of our performance throughout the contract term. The timing of revenue recognition for the manufacturing of new build heat exchangers within our United States industrial services segment depends on the payment terms of the contract, as our performance does not create an asset with an alternative use to us. For those contracts for which we have a right to payment for performance completed to date at all times throughout our performance, inclusive of a cancellation, we recognize revenue over time. For these performance obligations, we use a cost-to-cost input method to measure our progress towards complete satisfaction of the performance obligation as we believe it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. However, for those contracts for which we do not have a right, at all times, to payment for performance completed to date, we recognize revenue at the point in time when control is transferred to the customer. For bill-and-hold arrangements, revenue is recognized when the customer obtains control of the heat exchanger, which may be prior to shipping if certain recognition criteria are met. For certain of our revenue streams, such as call-out repair and service work, outage services, refinery turnarounds, and specialty welding services that are performed under time and materials contracts, our progress towards complete satisfaction of such performance obligations is measured using an output method as the customer receives and consumes the benefits of our performance completed to date. Changes in Estimates
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of the consolidated financial statements, we consider all highly liquid instruments with original maturities of three months or less to be cash equivalents. We maintain a centralized cash management system whereby our excess cash balances are invested in high quality short-term money market instruments, which are considered cash equivalents. We have cash balances in certain of our domestic bank accounts that exceed federally insured limits.
Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit Losses Accounts receivable are recognized in the period we deliver goods and services to our customers or when our right to consideration is unconditional. The Company maintains an allowance for credit losses to reduce outstanding receivables to their net realizable value. Judgment is required when determining expected credit losses. Estimates of such losses are recorded when we believe a customer, or group of customers, may not be able to meet their financial obligations due to deterioration in financial condition or credit rating. Factors relevant to our assessment include our prior collection history with our customers, the related aging of past due balances, projections of credit losses based on historical trends in credit quality indicators or past events, and forecasts of future economic conditions. In addition to monitoring delinquent accounts, management reviews the credit quality of its receivables by, among other things, obtaining credit ratings of significant customers, assessing economic and market conditions, and evaluating material changes to a customer’s business, cash flows, and financial condition.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined principally using the average cost method. Refer to Note 6 - Inventories of the notes to consolidated financial statements for additional information.
Leases	Leases At the inception of a contract, we determine whether the arrangement is or contains a lease. Leases are classified as either operating or finance, based on our evaluation of certain criteria. With the exception of short-term leases (leases with an initial term of 12 months or less), we record right-of-use assets and corresponding lease liabilities on the Consolidated Balance Sheets for all leases with contractual fixed payments. Lease liabilities are measured at the present value of remaining lease payments, while right-of-use assets are initially set equal to the lease liability, as adjusted for any payments made prior to lease commencement, lease incentives, and any initial direct costs incurred by us. For operating leases, rent expense is recognized on a straight-line basis over the term of the lease, and right-of-use assets are subsequently re-measured to reflect the effect of uneven lease payments. For finance leases, right-of-use assets are amortized on a straight-line basis over the shorter of the lease term or the useful life of the underlying asset. Expenses for finance leases include the amortization of right-of-use assets, which is recorded as depreciation and amortization expense, and interest expense, which reflects interest accrued on the lease liability. Short-term leases are not recorded on the Consolidated Balance Sheets but are expensed on a straight-line basis over the lease term. The majority of the Company’s short-term leases relate to equipment used on construction projects. Such equipment leases are considered short-term in nature unless it is reasonably certain that the equipment will be leased for a period greater than 12 months. Refer to Note 16 - Leases of the notes to consolidated financial statements for additional information. We lease real estate, vehicles, and equipment under various arrangements which are classified as either operating or finance leases. A lease exists when a contract or part of a contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In determining whether a lease exists, we consider whether a contract provides us with both: (a) the right to obtain substantially all of the economic benefits from the use of the identified asset and (b) the right to direct the use of the identified asset. Many of our leases include base rental periods coupled with options to renew or terminate the lease, generally at our discretion. Certain leases additionally include options to purchase the leased asset. In evaluating the lease term, we consider whether we are reasonably certain to exercise such options. To the extent a significant economic incentive exists to exercise an option, that option is included within the lease term. However, based on the nature of our lease arrangements, options generally do not provide us with a significant economic incentive and are therefore excluded from the lease term for the majority of our arrangements. Our leases typically include a combination of fixed and variable payments. Fixed payments are generally included when measuring the right-of-use asset and lease liability. Variable payments, which primarily represent payments based on usage of the underlying asset, are generally excluded from such measurement and expensed as incurred. In addition, certain of our lease arrangements may contain a lease coupled with an arrangement to provide other services, such as maintenance, or may require us to make other payments on behalf of the lessor related to the leased asset, such as payments for taxes or insurance. We account for these non-lease components together with the associated lease component for each of our asset classes. The measurement of right-of-use assets and lease liabilities requires us to estimate appropriate discount rates. To the extent the rate implicit in the lease is readily determinable, such rate is utilized. However, based on information available at lease commencement for the majority of our leases, the rate implicit in the lease is not known. In these instances, we utilize an incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments.
Property, Plant, and Equipment	Property, Plant, and Equipment Property, plant, and equipment is stated at cost. Depreciation, including amortization of assets under finance leases, is recorded using the straight-line method over estimated useful lives of 3 to 10 years for machinery and equipment, 3 to 7 years for vehicles, furniture and fixtures, and computer hardware/software, and 25 years for buildings. Leasehold improvements are amortized over the shorter of the remaining lease term or the expected useful life of the improvement.
Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets	Goodwill, Identifiable Intangible Assets, and Other Long-Lived Assets
Insurance Liabilities	Insurance Liabilities
Foreign Operations	Foreign Operations
Income Taxes	Income Taxes The Company follows the liability method of accounting for income taxes. Under this method, deferred income tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement and income tax bases of assets and liabilities as well as for net operating loss and tax credit carryforwards. Deferred income taxes are valued using enacted tax rates expected to be in effect when income taxes are paid or recovered, with the effect of a change in tax laws or rates recognized in the statement of operations in the periods in which such change is enacted. The ultimate realization of deferred income tax assets is dependent upon the generation of future taxable income during the period in which those temporary differences become deductible. Deferred income taxes are recorded net of a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. In making such determination, we consider all available evidence, including projections of future taxable income, tax-planning strategies, and recent results of operations.
Valuation of Share-based Compensation Plans	Valuation of Share-Based Compensation Our share-based compensation plans and programs are administered by our Board of Directors or its Compensation and Personnel Committee. See Note 13 - Share-Based Compensation Plans of the notes to consolidated financial statements for additional information regarding these share-based compensation plans and programs. NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Continued) We recognize expense for all share-based payments issued to acquire goods or services based on the fair value of such payments. Compensation expense related to share-based awards is generally recognized on a straight-line basis over the requisite service period, which is the vesting period. The benefits of tax deductions in excess of recognized compensation expense are recognized in the Consolidated Statements of Operations when the underlying awards vest or are settled.
New Accounting Pronouncements	New Accounting Pronouncements The Financial Accounting Standards Board (the “FASB”) has issued an Accounting Standards Update (“ASU”), which provides temporary optional expedients and exceptions to existing U.S. GAAP. This guidance is aimed at easing the financial reporting burdens related to reference rate reform, including the market transition from the London interbank offered rate (“LIBOR”), or other interbank offered rates, to alternative reference rates. Such accounting pronouncement, as amended, allows entities to account for and present certain contract modifications, which occur before December 31, 2024 and result from the transition to an alternative reference rate, as an event that does not require remeasurement at the modification date or reassessment of a previous accounting determination. In order to utilize such guidance, an entity must first conclude that the modified terms directly replace or have the potential to replace an eligible reference rate due to reference rate reform, and that any contemporaneous changes to other terms that change, or have the potential to change, the amount or timing of contractual cash flows are related to the replacement of a reference rate. During the second quarter of 2023, we amended our then existing credit agreement to change the reference rate from LIBOR to an interest rate based on the secured overnight financing rate, as administered by the Federal Reserve Bank of New York (“SOFR”). As such amendment was within the scope of the aforementioned guidance, we adopted this accounting pronouncement and utilized the optional expedients referenced above. We are not exposed to any other material contracts that reference LIBOR. The adoption of this accounting pronouncement did not have a material impact on our financial position and/or results of operations. In November 2023, the FASB issued an ASU, which expands the required disclosure for reportable segments. This guidance requires entities to disclose significant segment expenses and other segment items on an annual and interim basis and to provide in interim periods all segment disclosures which are currently required annually. This ASU additionally requires entities to disclose the title and position of the individual or the name of the group or committee identified as its chief operating decision-maker. Such guidance, which is required to be applied retrospectively, is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, although early adoption is permitted. While the adoption of this ASU will not have an impact on our financial position and/or results of operations, we are currently evaluating the impact to our segment disclosures. In December 2023, the FASB issued an ASU intended to enhance the transparency and decision-usefulness of income tax disclosures. Such guidance requires entities to provide additional information within their income tax rate reconciliation, including further disclosure of federal, state, and foreign income taxes and to provide more details about these reconciling items if a quantitative threshold is met. This guidance additionally requires expanded disclosure of income taxes paid, including amounts paid for federal, state, and foreign taxes. This ASU, which is required to be applied prospectively, is effective for fiscal years beginning after December 15, 2024, although early adoption and retrospective application is permitted. While the adoption of this ASU will not have an impact on our financial position and/or results of operations, we are currently evaluating the impact on our income tax disclosures, including the processes and controls around the collection of this information.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2023
Accounting Policies [Abstract]
Accounts Receivable, Allowance for Credit Losses	The change in the allowance for credit losses for the year ended December 31, 2023 was as follows (in thousands): Balance at December 31, 2022 $ 22,382 Provision for credit losses 7,859 Amounts written off against the allowance, net of recoveries (7,739) Balance at December 31, 2023 $ 22,502

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
Revenue from Contracts with Customers (Tables)	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Cumulative Catch-Up Adjustment	Based on an evaluation of individual projects that had revisions to total estimated costs, or anticipated contract value, which resulted in a reduction of profitability in excess of $1.0 million, our operating results were negatively impacted during the years ended December 31, 2023, 2022, and 2021, as summarized in the following table (in thousands): 2023 2022 2021 United States electrical construction and facilities services $ 12,535 $ 33,463 $ 4,627 United States mechanical construction and facilities services 10,864 13,679 2,264 United States building services 5,658 1,261 — Total impact $ 29,057 $ 48,403 $ 6,891
Disaggregation of Revenues	The following tables provide further disaggregation of our revenues by categories we use to evaluate our financial performance within each of our reportable segments (in thousands, except for percentages). Refer to Note 18 - Segment Information of the notes to consolidated financial statements for additional information on how we disaggregate our revenues by reportable segment. Due to continued growth in certain of our end markets, during 2023, we have expanded the market sectors included in the disclosure for each of our United States construction segments, as shown below. All prior period disclosures have been adjusted to additionally reflect these changes. 2023 % of 2022 % of 2021 % of United States electrical construction and facilities services: Network and communications market sector $ 934,455 34 % $ 801,052 33 % $ 621,139 30 % Commercial market sector 402,886 14 % 414,539 17 % 398,996 20 % Manufacturing and industrial market sector 394,804 14 % 301,606 12 % 230,894 11 % Healthcare market sector 242,931 9 % 178,348 7 % 107,442 5 % High-tech manufacturing market sector 140,471 5 % 88,544 4 % 35,196 2 % Institutional market sector 147,375 5 % 154,077 6 % 178,729 9 % Transportation market sector 167,976 6 % 166,563 7 % 196,313 10 % Water and wastewater market sector 21,234 1 % 21,251 1 % 14,962 1 % Hospitality and entertainment market sector 81,815 3 % 33,818 1 % 23,257 1 % Short duration projects (1) 186,722 7 % 211,797 9 % 185,277 9 % Service work 65,338 2 % 65,709 3 % 40,963 2 % 2,786,007 2,437,304 2,033,168 Less intersegment revenues (2,284) (4,190) (3,275) Total segment revenues $ 2,783,723 $ 2,433,114 $ 2,029,893 2023 % of 2022 % of 2021 % of United States mechanical construction and facilities services: Network and communications market sector $ 410,397 8 % $ 295,261 7 % $ 279,953 7 % Commercial market sector 1,115,993 22 % 1,079,872 25 % 1,042,751 27 % Manufacturing and industrial market sector 698,993 14 % 632,332 15 % 579,176 15 % Healthcare market sector 489,485 10 % 479,937 11 % 487,111 12 % High-tech manufacturing market sector 845,251 16 % 320,597 7 % 173,302 4 % Institutional market sector 316,255 6 % 331,727 8 % 263,285 7 % Transportation market sector 42,789 1 % 57,026 1 % 84,503 2 % Water and wastewater market sector 286,912 6 % 261,501 6 % 213,314 5 % Hospitality and entertainment market sector 52,919 1 % 44,615 1 % 66,059 2 % Short duration projects (1) 324,056 6 % 333,066 8 % 292,795 8 % Service work 500,853 10 % 467,156 11 % 446,786 11 % 5,083,903 4,303,090 3,929,035 Less intersegment revenues (9,100) (10,882) (6,835) Total segment revenues $ 5,074,803 $ 4,292,208 $ 3,922,200 _________________ (1) Represents those projects which generally are completed within three months or less. NOTE 3 - REVENUE FROM CONTRACTS WITH CUSTOMERS (Continued) 2023 % of 2022 % of 2021 % of United States building services: Mechanical services $ 2,042,244 65 % $ 1,748,455 64 % $ 1,590,506 65 % Commercial site-based services 865,232 28 % 810,210 29 % 680,351 28 % Government site-based services 212,658 7 % 196,288 7 % 184,272 7 % Total segment revenues $ 3,120,134 $ 2,754,953 $ 2,455,129 2023 % of 2022 % of 2021 % of United States industrial services: Field services $ 991,466 85 % $ 972,894 87 % $ 853,143 86 % Shop services 176,324 15 % 145,873 13 % 133,264 14 % Total segment revenues $ 1,167,790 $ 1,118,767 $ 986,407 Total United States operations $ 12,146,450 $ 10,599,042 $ 9,393,629 2023 % of 2022 % of 2021 % of United Kingdom building services: Service work $ 210,414 48 % $ 221,123 46 % $ 261,889 51 % Project work 226,009 52 % 255,955 54 % 248,062 49 % Total segment revenues $ 436,423 $ 477,078 $ 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580
Contract Assets and Contract Liabilities	Net contract liabilities in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Contract assets, current $ 269,885 $ 273,176 Contract assets, non-current — — Contract liabilities, current (1,595,109) (1,098,263) Contract liabilities, non-current (1,812) (2,273) Net contract liabilities $ (1,327,036) $ (827,360)
Net Contract Liabilities on Uncompleted Construction Projects	Included within net contract liabilities were $1,261.1 million and $763.2 million of net contract liabilities on uncompleted construction projects as of December 31, 2023 and 2022, respectively, as follows (in thousands): December 31, 2023 December 31, 2022 Costs incurred on uncompleted construction contracts $ 15,100,829 $ 13,231,612 Estimated earnings, thereon 2,381,049 2,025,929 17,481,878 15,257,541 Less: billings to date 18,742,934 16,020,704 $ (1,261,056) $ (763,163)
Remaining Performance Obligations	The following table presents the transaction price allocated to remaining unsatisfied performance obligations (“remaining performance obligations”) for each of our reportable segments and their respective percentages of total remaining performance obligations as of December 31, 2023 (in thousands, except for percentages): December 31, 2023 % of Total Remaining performance obligations: United States electrical construction and facilities services $ 2,387,844 27 % United States mechanical construction and facilities services 4,940,519 56 % United States building services 1,264,818 14 % United States industrial services 113,291 1 % Total United States operations 8,706,472 98 % United Kingdom building services 140,949 2 % Total operations $ 8,847,421 100 %
Remaining Performance Obligations, Expected Timing of Satisfaction	Refer to the table below for additional information regarding our remaining performance obligations, including an estimate of when we expect to recognize such remaining performance obligations as revenue (in thousands): Within Greater than one year Remaining performance obligations: United States electrical construction and facilities services $ 1,978,179 $ 409,665 United States mechanical construction and facilities services 4,314,365 626,154 United States building services 1,157,845 106,973 United States industrial services 113,291 — Total United States operations 7,563,680 1,142,792 United Kingdom building services 94,711 46,238 Total operations $ 7,658,391 $ 1,189,030

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
Earnings Per Share (Tables)	Dec. 31, 2023
Earnings Per Share [Abstract]
Calculation Of Basic And Diluted Earnings Per Common Share	The following table summarizes our calculation of Basic and Diluted Earnings per Common Share (“EPS”) for the years ended December 31, 2023, 2022, and 2021 (in thousands, except share and per share data): 2023 2022 2021 Numerator: Net income attributable to EMCOR Group, Inc. $ 632,994 $ 406,122 $ 383,532 Denominator: Weighted average shares outstanding used to compute basic earnings 47,358,467 49,931,940 54,068,982 Effect of dilutive securities—Share-based awards 205,791 204,322 278,552 Shares used to compute diluted earnings per common share 47,564,258 50,136,262 54,347,534 Basic earnings per common share $ 13.37 $ 8.13 $ 7.09 Diluted earnings per common share $ 13.31 $ 8.10 $ 7.06

Inventories (Tables)

Inventories (Tables)	12 Months Ended
Inventories (Tables)	Dec. 31, 2023
Inventory Disclosure [Abstract]
Inventories	Inventories in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Raw materials and construction materials $ 94,447 $ 74,014 Work in process 16,327 11,627 Inventories $ 110,774 $ 85,641

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
Property, Plant, and Equipment (Tables)	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Property, plant, and equipment in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2023 and 2022 (in thousands): December 31, 2023 December 31, 2022 Machinery and equipment $ 224,456 $ 206,249 Vehicles 76,489 68,858 Furniture and fixtures 27,415 25,253 Computer hardware/software 102,682 109,166 Land, buildings, and leasehold improvements 142,114 130,358 Construction in progress 13,514 6,060 Finance lease right-of-use assets (1) 4,932 6,117 591,602 552,061 Accumulated depreciation and amortization (412,224) (394,242) $ 179,378 $ 157,819 ____________________________________________ (1) Finance lease right-of-use assets are recorded net of accumulated amortization.

Goodwill, Identifiable Intang_2

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill by reportable segment during the years ended December 31, 2023 and 2022 were as follows (in thousands): United States United States United States United States Total Balance at December 31, 2021 $ 159,512 $ 303,887 $ 312,781 $ 114,088 $ 890,268 Acquisitions 17,601 6,942 4,340 — 28,883 Intersegment transfers 900 4,500 (5,400) — — Balance at December 31, 2022 178,013 315,329 311,721 114,088 919,151 Acquisitions — 4,524 32,874 — 37,398 Intersegment transfers — (1,500) 1,500 — — Balance at December 31, 2023 $ 178,013 $ 318,353 $ 346,095 $ 114,088 $ 956,549
Schedule of Intangible Assets	Identifiable intangible assets as of December 31, 2023 and 2022 consisted of the following (in thousands): December 31, 2023 Gross Accumulated Accumulated Impairment Charge Total Customer relationships $ 807,766 $ (482,594) $ (4,834) $ 320,338 Trade names (indefinite-lived) 299,271 — (58,933) 240,338 Developed technology/Vendor network 95,661 (78,788) — 16,873 Trade names (finite-lived) 35,991 (27,800) — 8,191 Contract backlog 84,845 (84,553) — 292 Total $ 1,323,534 $ (673,735) $ (63,767) $ 586,032 December 31, 2022 Gross Accumulated Accumulated Total Customer relationships $ 762,516 $ (427,211) $ (4,834) $ 330,471 Trade names (indefinite-lived) 289,121 — (58,933) 230,188 Developed technology/Vendor network 95,661 (74,238) — 21,423 Trade names (finite-lived) 33,791 (25,690) — 8,101 Contract backlog 83,245 (79,453) — 3,792 Total $ 1,264,334 $ (606,592) $ (63,767) $ 593,975
Schedule of Estimated Future Amortization Expense	The following table presents the estimated future amortization expense of identifiable intangible assets in the following years (in thousands): 2024 $ 63,873 2025 62,369 2026 55,782 2027 42,583 2028 33,818 Thereafter 87,269 $ 345,694

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule Of Debt	Debt in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2022 (in thousands): December 31, 2022 Term loan $ 242,813 Unamortized debt issuance costs (2,080) Finance lease liabilities 6,459 Total debt 247,192 Less: current maturities 15,567 Total long-term debt $ 231,625

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule Of Assets And Liabilities Carried At Fair Value Measured On A Recurring Basis	The following tables summarize the assets and liabilities carried at fair value measured on a recurring basis as of December 31, 2023 and 2022 (in thousands): Assets at Fair Value as of December 31, 2023 Asset Category Level 1 Level 2 Level 3 Total Cash and cash equivalents (1) $ 789,750 $ — $ — $ 789,750 Deferred compensation plan assets (2) 47,315 — — 47,315 Total $ 837,065 $ — $ — $ 837,065 _________________ (1) Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2023, we had $497.3 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. (2) Deferred compensation plan assets are classified as “Other assets” in the Consolidated Balance Sheets. NOTE 10 - FAIR VALUE MEASUREMENTS (Continued) Assets at Fair Value as of December 31, 2022 Asset Category Level 1 Level 2 Level 3 Total Cash and cash equivalents (1) $ 456,439 $ — $ — $ 456,439 Deferred compensation plan assets (2) 36,882 — — 36,882 Restricted cash (3) 629 — — 629 Total $ 493,950 $ — $ — $ 493,950 _________________ (1) Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2022, we had $209.4 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. (2) Deferred compensation plan assets are classified as “Other assets” in the Consolidated Balance Sheets. (3) Restricted cash is classified as “Prepaid expenses and other” in the Consolidated Balance Sheets. Restricted cash primarily represents cash held in account for use on customer contracts.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax	For the years ended December 31, 2023, 2022, and 2021, our income tax provision was calculated based on income before income taxes as follows (in thousands): 2023 2022 2021 United States $ 844,002 $ 523,273 $ 497,421 Foreign 28,851 35,477 31,882 $ 872,853 $ 558,750 $ 529,303
Schedule of Income Tax Provision	The income tax provision for the years ended December 31, 2023, 2022, and 2021 consisted of the following (in thousands): 2023 2022 2021 Current provision: Federal $ 187,463 $ 100,707 $ 95,782 State and local 62,316 36,547 35,883 Foreign 6,396 4,891 4,420 256,175 142,145 136,085 Deferred (benefit) provision (16,651) 10,483 9,517 $ 239,524 $ 152,628 $ 145,602
Schedule of U.S. Statutory Income Tax Rate Rec	Items accounting for the differences between income taxes computed at the federal statutory rate and the income tax provision for the years ended December 31, 2023, 2022, and 2021 were as follows (in thousands): 2023 2022 2021 Federal income taxes at the statutory rate $ 183,230 $ 117,338 $ 111,118 State and local income taxes, net of federal tax benefits 46,752 29,519 31,257 Permanent differences 9,513 5,261 5,316 Foreign income taxes (including UK statutory rate changes) 640 (155) (2,241) Other (611) 665 152 $ 239,524 $ 152,628 $ 145,602
Schedule of Deferred Tax Assets and Liabilities	The deferred income tax assets and deferred income tax liabilities recorded as of December 31, 2023 and 2022 were as follows (in thousands): December 31, 2023 December 31, 2022 Deferred income tax assets: Excess of amounts expensed for financial statement purposes over amounts deducted for income tax purposes: Insurance liabilities $ 59,667 $ 57,278 Operating lease liabilities 92,410 78,391 Deferred compensation 54,313 40,682 Other (including liabilities and reserves) 40,110 35,584 Total deferred income tax assets 246,500 211,935 Valuation allowance for deferred tax assets (4,385) (3,580) Net deferred income tax assets 242,115 208,355 Deferred income tax liabilities: Costs capitalized for financial statement purposes and deducted for income tax purposes: Goodwill and identifiable intangible assets (165,073) (153,767) Operating lease right-of-use assets (85,883) (73,134) Depreciation of property, plant, and equipment (30,075) (28,435) Pension asset (4,660) (4,082) Other (13,063) (10,500) Total deferred income tax liabilities (298,754) (269,918) Net deferred income tax liabilities $ (56,639) $ (61,563)

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
Share-Based Compensation Plans (Tables)	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of activity of restricted stock units	The following table summarizes activity regarding restricted stock units since December 31, 2020: Shares Weighted Balance, December 31, 2020 397,918 $ 73.16 Granted 129,859 $ 96.32 Forfeited (2,242) $ 78.86 Vested (121,067) $ 77.86 Balance, December 31, 2021 404,468 $ 79.16 Granted 107,621 $ 123.52 Forfeited (4,665) $ 105.88 Vested (189,830) $ 67.40 Balance, December 31, 2022 317,594 $ 100.83 Granted 103,024 $ 156.06 Forfeited (3,018) $ 118.59 Vested (122,751) $ 90.38 Balance, December 31, 2023 294,849 $ 124.30

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
Retirement Plans (Tables)	Dec. 31, 2023
Retirement Benefits [Abstract]
Schedule of Changes in Benefit Obligations and Assets	The change in benefit obligations and assets of the UK Plan for the years ended December 31, 2023 and 2022 consisted of the following components (in thousands): 2023 2022 Change in pension benefit obligation Benefit obligation at beginning of year $ 193,956 $ 349,147 Interest cost 9,722 5,693 Actuarial loss (gain) 651 (116,372) Benefits paid (10,411) (11,095) Foreign currency exchange rate changes 10,179 (33,417) Benefit obligation at end of year 204,097 193,956 Change in pension plan assets Fair value of plan assets at beginning of year 210,284 356,532 Actual return (loss) on plan assets 10,563 (105,544) Employer contributions 1,564 4,875 Benefits paid (10,411) (11,095) Foreign currency exchange rate changes 11,077 (34,484) Fair value of plan assets at end of year 223,077 210,284 Funded status at end of year $ 18,980 $ 16,328
Schedule of Weighted Average Assumptions Used To Calculate Benefit Obligation	The assumptions used to determine benefit obligations of the UK Plan as of December 31, 2023 and 2022 were as follows: 2023 2022 Discount rate 4.8 % 5.0 %
Components Of Net Periodic Pension Cost (Income)	The components of net periodic pension cost (income) of the UK Plan for the years ended December 31, 2023, 2022, and 2021 were as follows (in thousands): 2023 2022 2021 Interest cost $ 9,722 $ 5,693 $ 5,326 Expected return on plan assets (11,417) (12,088) (12,726) Amortization of unrecognized loss 2,611 2,073 3,642 Net periodic pension cost (income) $ 916 $ (4,322) $ (3,758)
Schedule of Weighted Average Assumptions Used To Calculate Net Periodic Pension Cost	The assumptions used to determine net periodic pension cost of the UK Plan for the years ended December 31, 2023, 2022, and 2021 were as follows: 2023 2022 2021 Discount rate 5.0 % 1.8 % 1.4 % Annual rate of return on plan assets 5.7 % 3.9 % 3.9 %
Schedule of Net Periodic Benefit Cost Not yet Recognized	Amounts pertaining to the UK Plan not yet reflected in net periodic pension cost and included in accumulated other comprehensive loss were as follows (in thousands): December 31, 2023 December 31, 2022 Unrecognized actuarial losses $ 82,344 $ 79,313
Schedule of Weighted Average Asset Allocations and Weighted Average Target Allocations	The weighted average asset allocations and weighted average target allocations at December 31, 2023 and 2022 were as follows: Asset Category Target Asset Allocation 2023 Actual December 31, 2023 Target Asset Allocation 2022 Actual December 31, 2022 Debt 90.0 % 87.1 % 75.0 % 80.7 % Cash and cash equivalents — % 3.9 % 15.0 % 9.4 % Real estate 10.0 % 9.0 % 10.0 % 9.9 % Total 100.0 % 100.0 % 100.0 % 100.0 %
Schedule of Plan Assets Fair Value Hierarchy	The following tables set forth the fair value of assets of the UK Plan as of December 31, 2023 and 2022 (in thousands): Assets at Fair Value as of December 31, 2023 Asset Category Level 1 Level 2 Level 3 Total Corporate debt funds $ — $ 44,504 $ — $ 44,504 Government bond funds — 63,934 — 63,934 Cash and cash equivalents 8,797 — — 8,797 Total plan assets in fair value hierarchy $ 8,797 $ 108,438 $ — 117,235 Plan assets measured using NAV as a practical expedient: (1) Debt funds 85,786 Real estate funds 20,056 Total plan assets at fair value $ 223,077 Assets at Fair Value as of December 31, 2022 Asset Category Level 1 Level 2 Level 3 Total Corporate debt funds $ — $ 23,998 $ — $ 23,998 Government bond funds — 45,619 — 45,619 Cash and cash equivalents 19,829 — — 19,829 Total plan assets in fair value hierarchy $ 19,829 $ 69,617 $ — 89,446 Plan assets measured using NAV as a practical expedient: (1) Debt funds 99,990 Real estate funds 20,848 Total plan assets at fair value $ 210,284 _________________ (1) Certain investments measured using net asset value (“NAV”) as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the total fair value of plan assets. NAV is determined by the respective fund manager based on the fair value of the underlying assets held by the fund, less its liabilities, divided by the number of units outstanding.
Schedule of Expected Benefit Payments	The following estimated benefit payments are expected to be made from the UK Plan in the following years (in thousands): Pension 2024 $ 10,736 2025 $ 11,185 2026 $ 11,689 2027 $ 12,079 2028 $ 12,598 Succeeding five years $ 67,955
Schedule of Multiemployer Plans	The following table lists all MEPPs to which our contributions exceeded $2.0 million in 2023. This table also lists all MEPPs to which we contributed in 2023 in excess of $0.5 million for MEPPs in the critical status, “red zone,” and $1.0 million for MEPPs in the endangered status, “orange or yellow zones,” as defined by the PPA (in thousands): Pension Fund EIN/Pension Plan Number PPA Zone Status (1) FIP/RP Contributions Contributions greater than 5% of total plan contributions (2) Expiration 2023 2022 2023 2022 2021 National Automatic Sprinkler Industry Pension Fund 52-6054620 001 Green Green NA $ 25,559 $ 21,583 $ 20,987 Yes March 2024 to July 2027 National Electrical Benefit Fund 53-0181657 001 Green Green NA 18,128 15,192 12,310 Yes February 2024 to November 2027 United Association National Pension Fund 52-6152779 001 Green Green NA 16,815 15,288 14,723 No January 2024 to May 2029 Sheet Metal Workers National Pension Fund 52-6112463 001 Green Green NA 10,797 9,505 10,307 No April 2024 to July 2028 Central Pension Fund of the IUOE & Participating Employers 36-6052390 001 Green Green NA 8,573 7,651 6,627 No January 2024 to December 2026 Electrical Workers Local No. 26 Pension Trust Fund 52-6117919 001 Green Green NA 8,283 7,844 9,346 Yes May 2024 to September 2027 Pension, Hospitalization & Benefit Plan of the Electrical Industry-Pension Trust Account 13-6123601 001 Green Green NA 7,198 8,122 7,355 No January 2025 to April 2025 Plumbers Pipefitters & Mechanical Equipment Service Local Union 392 Pension Plan 31-0655223 001 Red Red Implemented 7,010 7,674 7,110 Yes May 2024 to May 2025 Electrical Workers Pension Plan Local 103 IBEW 04-6063734 001 Green Green NA 6,537 2,900 — Yes August 2028 Northern California Pipe Trades Pension Plan 94-3190386 001 Green Green NA 6,317 3,238 2,663 No June 2024 to July 2024 Edison Pension Plan 93-6061681 001 Green Green NA 5,840 5,325 4,229 Yes December 2024 Sheet Metal Workers Pension Plan of Northern California 51-6115939 001 Red Red Implemented 5,738 6,074 7,850 Yes June 2024 to June 2026 San Diego Electrical Pension Plan 95-6101801 001 Green Green NA 5,511 4,258 4,068 Yes May 2024 Heating, Piping & Refrigeration Pension Fund 52-1058013 001 Green Green NA 5,315 4,625 5,591 Yes July 2024 to July 2025 Pipefitters Union Local 537 Pension Fund 51-6030859 001 Green Green NA 5,179 5,039 5,922 Yes August 2025 Southern California Pipe Trades Retirement Fund 51-6108443 001 Green Green NA 4,657 4,650 6,272 Yes August 2024 to August 2026 Electrical Contractors Association of the City of Chicago Local Union 134, IBEW Joint Pension Trust of Chicago Pension Plan 2 51-6030753 002 Green Green NA 4,432 3,516 4,225 No June 2024 to December 2024 IBEW Local 701 Pension Fund 36-6455509 001 Green Green NA 3,989 2,625 1,276 No May 2024 to September 2024 Eighth District Electrical Pension Fund 84-6100393 001 Green Green NA 3,844 3,339 3,298 Yes February 2024 to February 2027 Southern California IBEW-NECA Pension Trust Fund 95-6392774 001 Yellow Yellow Implemented 3,801 4,287 4,876 No May 2024 to November 2026 IBEW Local No. 82 Pension Plan 31-6127268 001 Green Green NA 3,701 2,549 956 Yes December 2026 Sheet Metal Workers Pension Plan of Southern California, Arizona & Nevada 95-6052257 001 Green Green NA 3,399 2,921 3,322 No June 2024 to July 2028 Kern County Electrical Workers Pension Fund 95-6123049 001 Green Green NA 3,299 1,542 1,167 Yes November 2027 NOTE 14 - RETIREMENT PLANS (Continued) Pension Fund EIN/Pension Plan Number PPA Zone Status (1) FIP/RP Contributions Contributions greater than 5% of total plan contributions (2) Expiration 2023 2022 2023 2022 2021 U.A. Local 393 Pension Trust Fund Defined Benefit 94-6359772 002 Green Green NA 3,263 3,517 3,507 Yes June 2024 to July 2024 Arizona Pipe Trades Pension Trust Fund 86-6025734 001 Green Green NA 3,048 2,940 2,020 Yes June 2024 Joint Pension Fund of Local Union No. 102 22-1615726 001 Green Green NA 2,868 1,762 1,531 Yes June 2024 Plumbers & Steamfitters Local 486 Pension Fund 52-6124449 001 Green Green NA 2,828 1,599 1,351 Yes December 2025 Plumbers & Pipefitters Local No. 189 Pension Fund 31-0894807 001 Green Green NA 2,557 1,272 596 Yes May 2024 to June 2025 Local No. 697 IBEW and Electrical Industry Pension Fund 51-6133048 001 Green Green NA 2,528 2,287 1,753 Yes May 2024 U.A. Plumbers Local 24 Pension Fund 22-6042823 001 Green Green NA 2,295 1,819 2,270 Yes April 2025 NECA-IBEW Pension Trust Fund 51-6029903 001 Green Green NA 2,228 3,034 2,491 No May 2024 to December 2024 IBEW 332 Pension Fund - Part A 94-2688032 004 Green Green NA 2,062 4,177 2,339 Yes May 2024 to June 2024 Plumbers & Pipefitters Local 162 Pension Fund 31-6125999 001 Yellow Yellow Implemented 1,243 1,132 1,034 Yes May 2024 to May 2026 Steamfitters Local Union No. 420 Pension Plan 23-2004424 001 Red Red Implemented 1,227 1,018 677 No April 2026 to May 2026 Boilermaker-Blacksmith National Pension Trust 48-6168020 001 Red Green Implemented 1,140 6,434 3,479 Yes April 2025 to September 2026 Plumbing & Pipe Fitting Local 219 Pension Fund 34-6682376 001 Red Red Implemented 919 1,172 1,167 Yes May 2026 Carpenters Pension Trust Fund for Northern California 94-6050970 001 Red Red Implemented 610 532 568 No June 2027 Other Multiemployer Pension Plans 56,091 53,723 51,818 Various Total Contributions $ 258,829 $ 236,165 $ 221,081 _________________ (1) The zone status represents the most recent available information for the respective MEPP, which may be from 2022 or earlier for the 2023 year and from 2021 or earlier for the 2022 year. In general, plans with a “green” zone status have a funding ratio of at least 80%, plans with an “orange” or “yellow” zone status have a funding ratio of between 65% and less than 80%, and plans with a “red” zone status are less than 65% funded or are projected to have a funding deficiency in any of the next ten years.

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2023
Leases [Abstract]
Schedule of Lease Assets and Liabilities	The following table presents our lease-related assets and liabilities as of December 31, 2023 and 2022 (in thousands): Classification on the Consolidated Balance Sheet December 31, December 31, Assets Operating lease assets Operating lease right-of-use assets $ 310,498 $ 268,063 Finance lease assets Property, plant, and equipment, net 4,932 6,117 Total lease assets $ 315,430 $ 274,180 Liabilities Current Operating Operating lease liabilities, current $ 75,236 $ 67,218 Finance Current maturities of long-term debt and finance lease liabilities 2,465 2,652 Noncurrent Operating Operating lease liabilities, long-term 259,430 220,764 Finance Long-term debt and finance lease liabilities 2,838 3,807 Total lease liabilities $ 339,969 $ 294,441
Schedule of Lease Costs	The following table presents information related to our lease expense for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Finance lease expense: Amortization expense $ 2,816 $ 3,550 $ 4,255 Interest expense 175 178 255 Operating lease expense 93,158 77,143 70,928 Short-term lease expense (1) 224,047 185,061 150,500 Variable lease expense 9,482 6,782 5,421 Total lease expense $ 329,678 $ 272,714 $ 231,359 _________________ (1) Short-term lease expense includes both leases and rentals with initial terms of one year or less and predominantly represents equipment used on construction projects. Sublease rental income was approximately $6.7 million, $3.8 million, and $0.2 million for the years ended December 31, 2023, 2022, and 2021, respectively. Lease Term and Discount Rate The following table presents certain information related to the lease terms and discount rates for our leases as of December 31, 2023 and 2022: December 31, December 31, Weighted-average remaining lease term: Operating leases 5.7 years 5.9 years Finance leases 2.9 years 2.9 years Weighted-average discount rate: Operating leases 4.11 % 3.45 % Finance leases 3.57 % 2.85 % Other Information The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 90,412 $ 74,927 $ 69,797 Operating cash flows used for finance leases $ 175 $ 178 $ 255 Financing cash flows used for finance leases $ 2,776 $ 3,551 $ 4,189 Right-of-use assets obtained in exchange for new operating lease liabilities $ 125,417 $ 75,027 $ 80,661 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,427 $ 2,209 $ 2,301
Schedule of Maturity of Operating Leases	The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2023 (in thousands): Operating Leases Finance Leases 2024 $ 87,058 $ 2,605 2025 69,127 1,533 2026 60,558 782 2027 47,961 389 2028 36,858 222 Thereafter 74,510 64 Total minimum lease payments 376,072 5,595 Less: Amount of lease payments representing interest (41,406) (292) Present value of future minimum lease payments $ 334,666 $ 5,303 Current portion of lease liabilities $ 75,236 $ 2,465 Noncurrent portion of lease liabilities 259,430 2,838 Present value of future minimum lease payments $ 334,666 $ 5,303
Schedule of Maturity of Finance Leases	The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2023 (in thousands): Operating Leases Finance Leases 2024 $ 87,058 $ 2,605 2025 69,127 1,533 2026 60,558 782 2027 47,961 389 2028 36,858 222 Thereafter 74,510 64 Total minimum lease payments 376,072 5,595 Less: Amount of lease payments representing interest (41,406) (292) Present value of future minimum lease payments $ 334,666 $ 5,303 Current portion of lease liabilities $ 75,236 $ 2,465 Noncurrent portion of lease liabilities 259,430 2,838 Present value of future minimum lease payments $ 334,666 $ 5,303

Additional Cash Flow Informat_2

Additional Cash Flow Information (Tables)	12 Months Ended
Additional Cash Flow Information (Tables)	Dec. 31, 2023
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	The following table presents information about cash paid for interest and income taxes for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Cash paid during the year for: Interest $ 16,246 $ 11,653 $ 5,259 Income taxes $ 230,496 $ 168,732 $ 130,811

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
Segment Information (Tables)	Dec. 31, 2023
Segment Reporting [Abstract]
Information About Reportable Segments	The following tables present financial information for each of our reportable segments for the years ended December 31, 2023, 2022, and 2021 (in thousands): 2023 2022 2021 Revenues from unrelated entities: United States electrical construction and facilities services $ 2,783,723 $ 2,433,114 $ 2,029,893 United States mechanical construction and facilities services 5,074,803 4,292,208 3,922,200 United States building services 3,120,134 2,754,953 2,455,129 United States industrial services 1,167,790 1,118,767 986,407 Total United States operations 12,146,450 10,599,042 9,393,629 United Kingdom building services 436,423 477,078 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580 2023 2022 2021 Total revenues: United States electrical construction and facilities services $ 2,786,895 $ 2,438,916 $ 2,033,863 United States mechanical construction and facilities services 5,134,686 4,338,584 3,935,737 United States building services 3,228,056 2,856,115 2,553,566 United States industrial services 1,179,321 1,175,469 1,021,217 Less intersegment revenues (182,508) (210,042) (150,754) Total United States operations 12,146,450 10,599,042 9,393,629 United Kingdom building services 436,423 477,078 509,951 Total operations $ 12,582,873 $ 11,076,120 $ 9,903,580 2023 2022 2021 Operating income (loss): United States electrical construction and facilities services $ 230,640 $ 148,728 $ 169,355 United States mechanical construction and facilities services 530,644 330,325 312,809 United States building services 182,995 146,639 124,335 United States industrial services 35,375 19,787 (1,666) Total United States operations 979,654 645,479 604,833 United Kingdom building services 25,681 29,838 27,998 Corporate administration (127,229) (110,440) (102,031) Impairment loss on long-lived assets (2,350) — — Total operations 875,756 564,877 530,800 Other items: Net periodic pension (cost) income (1,119) 4,311 3,625 Interest expense (17,199) (13,199) (6,071) Interest income 15,415 2,761 949 Income before income taxes $ 872,853 $ 558,750 $ 529,303 NOTE 18 - SEGMENT INFORMATION (Continued) 2023 2022 2021 Capital expenditures: United States electrical construction and facilities services $ 6,929 $ 11,228 $ 4,985 United States mechanical construction and facilities services 37,543 11,930 10,108 United States building services 19,843 13,303 11,539 United States industrial services 10,433 9,905 6,159 Total United States operations 74,748 46,366 32,791 United Kingdom building services 1,984 2,816 3,015 Corporate administration 1,672 107 386 Total operations $ 78,404 $ 49,289 $ 36,192 2023 2022 2021 Depreciation and amortization of property, plant, and equipment: United States electrical construction and facilities services $ 8,402 $ 7,543 $ 7,229 United States mechanical construction and facilities services 12,503 11,492 11,354 United States building services 15,672 12,964 12,090 United States industrial services 11,146 10,888 11,723 Total United States operations 47,723 42,887 42,396 United Kingdom building services 3,116 2,752 3,938 Corporate administration 983 1,657 2,013 Total operations $ 51,822 $ 47,296 $ 48,347 December 31, 2023 December 31, 2022 December 31, 2021 Contract assets: United States electrical construction and facilities services $ 73,464 $ 75,603 $ 48,382 United States mechanical construction and facilities services 97,252 99,632 89,102 United States building services 61,867 56,694 42,818 United States industrial services 17,129 10,727 18,992 Total United States operations 249,712 242,656 199,294 United Kingdom building services 20,173 30,520 30,849 Total operations $ 269,885 $ 273,176 $ 230,143 December 31, 2023 December 31, 2022 December 31, 2021 Contract liabilities: United States electrical construction and facilities services $ 399,550 $ 271,161 $ 200,966 United States mechanical construction and facilities services 925,481 594,453 386,518 United States building services 223,202 184,821 150,333 United States industrial services 17,366 17,746 16,481 Total United States operations 1,565,599 1,068,181 754,298 United Kingdom building services 29,510 30,082 33,836 Total operations $ 1,595,109 $ 1,098,263 $ 788,134 NOTE 18 - SEGMENT INFORMATION (Continued) December 31, 2023 December 31, 2022 December 31, 2021 Long-lived assets: United States electrical construction and facilities services $ 290,896 $ 302,448 $ 237,766 United States mechanical construction and facilities services 526,567 517,649 514,065 United States building services 574,917 497,892 500,368 United States industrial services 318,077 341,646 365,563 Total United States operations 1,710,457 1,659,635 1,617,762 United Kingdom building services 9,761 10,320 11,402 Corporate administration 1,741 990 2,535 Total operations $ 1,721,959 $ 1,670,945 $ 1,631,699 December 31, 2023 December 31, 2022 December 31, 2021 Total assets: United States electrical construction and facilities services $ 1,243,707 $ 1,078,405 $ 855,417 United States mechanical construction and facilities services 2,242,833 1,835,001 1,664,822 United States building services 1,382,664 1,206,518 1,097,568 United States industrial services 571,658 552,545 589,017 Total United States operations 5,440,862 4,672,469 4,206,824 United Kingdom building services 277,066 255,547 241,740 Corporate administration 891,793 596,591 992,882 Total operations $ 6,609,721 $ 5,524,607 $ 5,441,446

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant, and Equipment [Line Items]
Accounts receivable, net	$ 3,203,490,000	$ 2,567,371,000
Allowance for credit losses	22,502,000	22,382,000
Provision for credit losses	7,859,000	5,166,000	$ 8,041,000
Unrecognized income tax benefits	$ 0	0
Machinery and Equipment \| Minimum
Property, Plant, and Equipment [Line Items]
Estimated useful life	3 years
Machinery and Equipment \| Maximum
Property, Plant, and Equipment [Line Items]
Estimated useful life	10 years
Vehicles, Furniture and Fixtures, and Computer Hardware and Software \| Minimum
Property, Plant, and Equipment [Line Items]
Estimated useful life	3 years
Vehicles, Furniture and Fixtures, and Computer Hardware and Software \| Maximum
Property, Plant, and Equipment [Line Items]
Estimated useful life	7 years
Buildings
Property, Plant, and Equipment [Line Items]
Estimated useful life	25 years
Other accrued expenses and liabilities
Property, Plant, and Equipment [Line Items]
Insurance liabilities, current	$ 51,000,000	54,800,000
Other long-term obligations
Property, Plant, and Equipment [Line Items]
Insurance liabilities, noncurrent	229,800,000	221,700,000
Prepaid expenses and other
Property, Plant, and Equipment [Line Items]
Anticipated insurance recoveries, current	11,900,000	16,000,000
Other assets
Property, Plant, and Equipment [Line Items]
Anticipated insurance recoveries, noncurrent	$ 48,800,000	$ 59,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses, beginning balance	$ 22,382
Provision for credit losses	7,859	$ 5,166	$ 8,041
Amounts written off against the allowance, net of recoveries	(7,739)
Allowance for credit losses, ending balance	$ 22,502	$ 22,382

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($)	12 Months Ended
Revenue from Contracts with Customers (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue From Contract With Customers [Line Items]
Performance obligation satisfied in previous period	$ 16,500,000	$ 0	$ 0
Unbilled revenues for unapproved change orders	29,800,000	36,000,000
Claims on contract assets	6,700,000	3,800,000
Claim amounts within accounts receivable	15,400,000	0
Contractually billed amounts and retention related to contracts with unapproved change orders and claims	157,700,000	131,400,000
Net contract liabilities, construction	1,261,056,000	763,163,000
Contract asset impairment	0	0
Accounts receivable, retainage	$ 555,900,000	456,900,000
Accounts receivable, retainage estimated to be collected in next fiscal year	88%
Accounts payable, retainage	$ 93,600,000	$ 82,400,000
Accounts payable, retainage estimated to be paid in next fiscal year	90%
Remaining performance obligations	$ 8,847,421,000
Minimum
Revenue From Contract With Customers [Line Items]
Change in total estimated cost or anticipated contract value	1,000,000
Performance obligation satisfied in previous period	1,000,000
2023 Acquisitions
Revenue From Contract With Customers [Line Items]
Increase in contract assets from acquisitions	2,000,000
Increase in contract liabilities from acquisitions	3,800,000
Excluding2023Acquisitions
Revenue From Contract With Customers [Line Items]
Increase in net contract liabilities	497,900,000
United States Electrical Construction And Facilities Services
Revenue From Contract With Customers [Line Items]
Performance obligation satisfied in previous period	3,400,000
United States Mechanical Construction And Facilities Services
Revenue From Contract With Customers [Line Items]
Performance obligation satisfied in previous period	$ 13,100,000

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Schedule of Cumulative Catch-Up Adjustment (Details) - UNITED STATES - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cumulative Catch-Up Adjustment [Line Items]
Change in total estimated cost or anticipated contract value	$ 29,057	$ 48,403	$ 6,891
United States Electrical Construction And Facilities Services
Cumulative Catch-Up Adjustment [Line Items]
Change in total estimated cost or anticipated contract value	12,535	33,463	4,627
United States Mechanical Construction And Facilities Services
Cumulative Catch-Up Adjustment [Line Items]
Change in total estimated cost or anticipated contract value	10,864	13,679	2,264
United States Building Services
Cumulative Catch-Up Adjustment [Line Items]
Change in total estimated cost or anticipated contract value	$ 5,658	$ 1,261	$ 0

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues		$ 12,582,873	$ 11,076,120	$ 9,903,580
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		12,146,450	10,599,042	9,393,629
United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		2,783,723	2,433,114	2,029,893
United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		5,074,803	4,292,208	3,922,200
United States Building Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		3,120,134	2,754,953	2,455,129
United States Industrial Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		1,167,790	1,118,767	986,407
United Kingdom Building Services \| UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Revenues		436,423	477,078	509,951
Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		2,786,007	2,437,304	2,033,168
Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		5,083,903	4,303,090	3,929,035
Intersegment Eliminations [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		(2,284)	(4,190)	(3,275)
Intersegment Eliminations [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		(9,100)	(10,882)	(6,835)
Network and Communications Market Sector \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 934,455	$ 801,052	$ 621,139
Percentage of total segment revenues		34%	33%	30%
Network and Communications Market Sector \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 410,397	$ 295,261	$ 279,953
Percentage of total segment revenues		8%	7%	7%
Commercial Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 402,886	$ 414,539	$ 398,996
Percentage of total segment revenues		14%	17%	20%
Commercial Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 1,115,993	$ 1,079,872	$ 1,042,751
Percentage of total segment revenues		22%	25%	27%
Manufacturing and Industrial Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 394,804	$ 301,606	$ 230,894
Percentage of total segment revenues		14%	12%	11%
Manufacturing and Industrial Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 698,993	$ 632,332	$ 579,176
Percentage of total segment revenues		14%	15%	15%
Healthcare Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 242,931	$ 178,348	$ 107,442
Percentage of total segment revenues		9%	7%	5%
Healthcare Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 489,485	$ 479,937	$ 487,111
Percentage of total segment revenues		10%	11%	12%
High-Tech Manufacturing Market Sector \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 140,471	$ 88,544	$ 35,196
Percentage of total segment revenues		5%	4%	2%
High-Tech Manufacturing Market Sector \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 845,251	$ 320,597	$ 173,302
Percentage of total segment revenues		16%	7%	4%
Institutional Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 147,375	$ 154,077	$ 178,729
Percentage of total segment revenues		5%	6%	9%
Institutional Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 316,255	$ 331,727	$ 263,285
Percentage of total segment revenues		6%	8%	7%
Transportation Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 167,976	$ 166,563	$ 196,313
Percentage of total segment revenues		6%	7%	10%
Transportation Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 42,789	$ 57,026	$ 84,503
Percentage of total segment revenues		1%	1%	2%
Water and Wastewater Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 21,234	$ 21,251	$ 14,962
Percentage of total segment revenues		1%	1%	1%
Water and Wastewater Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 286,912	$ 261,501	$ 213,314
Percentage of total segment revenues		6%	6%	5%
Hospitality and Entertainment Market Sector [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 81,815	$ 33,818	$ 23,257
Percentage of total segment revenues		3%	1%	1%
Hospitality and Entertainment Market Sector [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 52,919	$ 44,615	$ 66,059
Percentage of total segment revenues		1%	1%	2%
Short Duration Projects [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues	[1]	$ 186,722	$ 211,797	$ 185,277
Percentage of total segment revenues		7%	9%	9%
Short Duration Projects [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues	[1]	$ 324,056	$ 333,066	$ 292,795
Percentage of total segment revenues		6%	8%	8%
Service Work [Member] \| Operating Segments [Member] \| United States Electrical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 65,338	$ 65,709	$ 40,963
Percentage of total segment revenues		2%	3%	2%
Service Work [Member] \| Operating Segments [Member] \| United States Mechanical Construction And Facilities Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 500,853	$ 467,156	$ 446,786
Percentage of total segment revenues		10%	11%	11%
Service Work [Member] \| Operating Segments [Member] \| United Kingdom Building Services \| UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Revenues		$ 210,414	$ 221,123	$ 261,889
Percentage of total segment revenues		48%	46%	51%
Mechanical Services [Member] \| Operating Segments [Member] \| United States Building Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 2,042,244	$ 1,748,455	$ 1,590,506
Percentage of total segment revenues		65%	64%	65%
Commercial Site-Based Services [Member] \| Operating Segments [Member] \| United States Building Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 865,232	$ 810,210	$ 680,351
Percentage of total segment revenues		28%	29%	28%
Government Site-Based Services [Member] \| Operating Segments [Member] \| United States Building Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 212,658	$ 196,288	$ 184,272
Percentage of total segment revenues		7%	7%	7%
Field Services [Member] \| Operating Segments [Member] \| United States Industrial Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 991,466	$ 972,894	$ 853,143
Percentage of total segment revenues		85%	87%	86%
Shop Services [Member] \| Operating Segments [Member] \| United States Industrial Services \| UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues		$ 176,324	$ 145,873	$ 133,264
Percentage of total segment revenues		15%	13%	14%
Project Work [Member] \| Operating Segments [Member] \| United Kingdom Building Services \| UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Revenues		$ 226,009	$ 255,955	$ 248,062
Percentage of total segment revenues		52%	54%	49%

[1] Represents those projects which generally are completed within three months or less.

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Schedule of Contract with Customer, Asset and Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract assets, current	$ 269,885	$ 273,176	$ 230,143
Contract assets, non-current	0	0
Contract liabilities, current	(1,595,109)	(1,098,263)	$ (788,134)
Contract liabilities, non-current	(1,812)	(2,273)
Net contract liabilities	$ (1,327,036)	$ (827,360)

Revenue from Contracts with C_7

Revenue from Contracts with Customers - Schedule of Net Contract Liabilities on Uncompleted Construction Projects (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Costs incurred on uncompleted construction contracts	$ 15,100,829	$ 13,231,612
Estimated earnings, thereon	2,381,049	2,025,929
Costs and estimated earnings on uncompleted construction contracts	17,481,878	15,257,541
Less: billings to date	18,742,934	16,020,704
Net contract liabilities, construction	$ (1,261,056)	$ (763,163)

Revenue from Contracts with C_8

Revenue from Contracts with Customers - Schedule of Revenue, Remaining Performance Obligation (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 8,847,421
Remaining performance obligations, percent	100%
UNITED STATES
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 8,706,472
Remaining performance obligations, percent	98%
UNITED STATES \| United States Electrical Construction And Facilities Services
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 2,387,844
Remaining performance obligations, percent	27%
UNITED STATES \| United States Mechanical Construction And Facilities Services
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 4,940,519
Remaining performance obligations, percent	56%
UNITED STATES \| United States Building Services
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 1,264,818
Remaining performance obligations, percent	14%
UNITED STATES \| United States Industrial Services
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 113,291
Remaining performance obligations, percent	1%
UNITED KINGDOM \| United Kingdom Building Services
Schedule of Remaining Performance Obligations [Line Items]
Remaining performance obligations	$ 140,949
Remaining performance obligations, percent	2%

Revenue from Contracts with C_9

Revenue from Contracts with Customers - Schedule of Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 8,847,421
UNITED STATES
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	8,706,472
UNITED STATES \| United States Electrical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	2,387,844
UNITED STATES \| United States Mechanical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	4,940,519
UNITED STATES \| United States Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	1,264,818
UNITED STATES \| United States Industrial Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	113,291
UNITED KINGDOM \| United Kingdom Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 140,949
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 7,658,391
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED STATES
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 7,563,680
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED STATES \| United States Electrical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 1,978,179
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED STATES \| United States Mechanical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 4,314,365
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED STATES \| United States Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 1,157,845
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED STATES \| United States Industrial Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 113,291
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| UNITED KINGDOM \| United Kingdom Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Remaining performance obligations	$ 94,711
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 1,189,030
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED STATES
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 1,142,792
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED STATES \| United States Electrical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 409,665
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED STATES \| United States Mechanical Construction And Facilities Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 626,154
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED STATES \| United States Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 106,973
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED STATES \| United States Industrial Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| UNITED KINGDOM \| United Kingdom Building Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Remaining performance obligations	$ 46,238

Acquisitions Of Businesses (Det

Acquisitions Of Businesses (Details) $ in Thousands	12 Months Ended
Acquisitions Of Businesses (Details) $ in Thousands	Dec. 31, 2023 USD ($) Company	Dec. 31, 2022 USD ($) Company	Dec. 31, 2021 USD ($) Company
Business Acquisition [Line Items]
Number of businesses acquired \| Company	8	6	8
Goodwill ascribed	$ 956,549	$ 919,151	$ 890,268
2022 Acquisitions
Business Acquisition [Line Items]
Purchase price		100,800
Working capital acquired		7,100
Other net liabilities acquired		1,100
Goodwill ascribed		28,900
Identifiable intangible assets ascribed		$ 65,900
2021 Acquisitions
Business Acquisition [Line Items]
Purchase price			131,200
Working capital acquired			22,900
Other net liabilities acquired			600
Goodwill ascribed			38,300
Identifiable intangible assets ascribed			70,600
Goodwill and identifiable intangible assets, tax deductible amount			$ 90,500
2023 Acquisitions
Business Acquisition [Line Items]
Purchase price	99,600
Working capital acquired	9,100
Other net liabilities acquired	6,100
Goodwill ascribed	37,400
Identifiable intangible assets ascribed	59,200
Goodwill and identifiable intangible assets, tax deductible amount	$ 29,600

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator
Net income attributable to EMCOR Group, Inc. (in US dollars)	$ 632,994	$ 406,122	$ 383,532
Denominator
Weighted average shares outstanding used to compute basic earnings per common share (in shares)	47,358,467	49,931,940	54,068,982
Effect of dilutive securities-Share-based awards (in shares)	205,791	204,322	278,552
Shares used to compute diluted earnings per common share (in shares)	47,564,258	50,136,262	54,347,534
Basic earnings per common share (in US dollars per share)	$ 13.37	$ 8.13	$ 7.09
Diluted earnings per common share (in US dollars per share)	$ 13.31	$ 8.10	$ 7.06

Earnings Per Share Antidilutive

Earnings Per Share Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	8,700	4,926	9,250

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials and construction materials	$ 94,447	$ 74,014
Work in process	16,327	11,627
Inventories	$ 110,774	$ 85,641

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		$ 591,602	$ 552,061
Accumulated depreciation and amortization		(412,224)	(394,242)
Property, plant, and equipment, net		179,378	157,819
Depreciation and amortization		51,822	47,296	$ 48,347
Machinery and equipment
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		224,456	206,249
Vehicles
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		76,489	68,858
Furniture and fixtures
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		27,415	25,253
Computer hardware/software
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		102,682	109,166
Land, buildings, and leasehold improvements
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		142,114	130,358
Construction in progress
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross		13,514	6,060
Finance lease right-of-use assets (1)
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment, gross	[1]	$ 4,932	$ 6,117

[1] Finance lease right-of-use assets are recorded net of accumulated amortization.

Goodwill, Identifiable Intang_3

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Oct. 01, 2023
Goodwill and Intangible Assets[Line Items]
Goodwill	$ 956,549,000	$ 919,151,000	$ 890,268,000
Goodwill impairment	$ 0	0	0
Goodwill, accumulated impairment loss			493,600,000
Amortization periods	7 years
Amortization of identifiable intangible assets	$ 67,143,000	61,315,000	64,089,000
Indefinite-Lived Intangible Assets
Goodwill and Intangible Assets[Line Items]
Other asset impairment charges, excluding goodwill	0	0	0
Finite-Lived Intangible Assets
Goodwill and Intangible Assets[Line Items]
Other asset impairment charges, excluding goodwill	0	0	0
Long-Lived Assets
Goodwill and Intangible Assets[Line Items]
Other asset impairment charges, excluding goodwill	2,400,000	0	0
2023 Acquisitions
Goodwill and Intangible Assets[Line Items]
Goodwill	37,400,000
Identifiable intangible assets acquired	59,200,000
2022 Acquisitions
Goodwill and Intangible Assets[Line Items]
Goodwill		28,900,000
Identifiable intangible assets acquired		65,900,000
2021 Acquisitions
Goodwill and Intangible Assets[Line Items]
Goodwill			38,300,000
Identifiable intangible assets acquired			70,600,000
Domestic Segments
Goodwill and Intangible Assets[Line Items]
Perpetual growth rate used for annual testing, percentage				2.50%
Domestic Construction
Goodwill and Intangible Assets[Line Items]
Weighted average cost of capital used in annual testing, percentage				10.90%
United States Electrical Construction And Facilities Services
Goodwill and Intangible Assets[Line Items]
Goodwill	$ 178,013,000	178,013,000	159,512,000
Goodwill allocated, percentage	18.60%
Effect of 50 Basis Point Increase in the Weighted Average Costs of Capital				$ 115,200,000
Effect of 50 Basis Point Decrease in the Perpetual Growth Rate				56,500,000
United States Mechanical Construction And Facilities Services
Goodwill and Intangible Assets[Line Items]
Goodwill	$ 318,353,000	315,329,000	303,887,000
Goodwill allocated, percentage	33.30%
Effect of 50 Basis Point Increase in the Weighted Average Costs of Capital				249,900,000
Effect of 50 Basis Point Decrease in the Perpetual Growth Rate				$ 137,100,000
United States Building Services
Goodwill and Intangible Assets[Line Items]
Goodwill	$ 346,095,000	311,721,000	312,781,000
Goodwill allocated, percentage	36.20%
Weighted average cost of capital used in annual testing, percentage				11.20%
Effect of 50 Basis Point Increase in the Weighted Average Costs of Capital				$ 84,200,000
Effect of 50 Basis Point Decrease in the Perpetual Growth Rate				$ 40,400,000
Goodwill, accumulated impairment loss			139,500,000
United States Industrial Services
Goodwill and Intangible Assets[Line Items]
Goodwill	$ 114,088,000	$ 114,088,000	114,088,000
Goodwill allocated, percentage	11.90%
Weighted average cost of capital used in annual testing, percentage				11%
Effect of 50 Basis Point Increase in the Weighted Average Costs of Capital				$ 25,200,000
Effect of 50 Basis Point Decrease in the Perpetual Growth Rate				$ 9,300,000
Goodwill, accumulated impairment loss			$ 354,100,000
Customer relationships
Goodwill and Intangible Assets[Line Items]
Amortization periods	7 years 3 months
Developed technology/Vendor network
Goodwill and Intangible Assets[Line Items]
Amortization periods	3 years 9 months
Trade names (finite-lived)
Goodwill and Intangible Assets[Line Items]
Amortization periods	5 years 9 months

Goodwill, Identifiable Intang_4

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets - Schedule of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Goodwill, Beginning balance	$ 919,151,000	$ 890,268,000
Acquisitions	37,398,000	28,883,000
Goodwill impairment	0	0	$ 0
Goodwill, intersegment transfers	0	0
Goodwill, Ending balance	956,549,000	919,151,000	890,268,000
United States Electrical Construction And Facilities Services
Goodwill [Roll Forward]
Goodwill, Beginning balance	178,013,000	159,512,000
Acquisitions	0	17,601,000
Goodwill, intersegment transfers	0	900,000
Goodwill, Ending balance	178,013,000	178,013,000	159,512,000
United States Mechanical Construction And Facilities Services
Goodwill [Roll Forward]
Goodwill, Beginning balance	315,329,000	303,887,000
Acquisitions	4,524,000	6,942,000
Goodwill, intersegment transfers	(1,500,000)	4,500,000
Goodwill, Ending balance	318,353,000	315,329,000	303,887,000
United States Building Services
Goodwill [Roll Forward]
Goodwill, Beginning balance	311,721,000	312,781,000
Acquisitions	32,874,000	4,340,000
Goodwill, intersegment transfers	1,500,000	(5,400,000)
Goodwill, Ending balance	346,095,000	311,721,000	312,781,000
United States Industrial Services
Goodwill [Roll Forward]
Goodwill, Beginning balance	114,088,000	114,088,000
Acquisitions	0	0
Goodwill, intersegment transfers	0	0
Goodwill, Ending balance	$ 114,088,000	$ 114,088,000	$ 114,088,000

Goodwill, Identifiable Intang_5

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets - Schedule of Finite-lived and Indefinite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	$ (673,735)	$ (606,592)
Total	345,694
Trade names (indefinite-lived), Accumulated Impairment Charge	(58,933)	(58,933)
Gross Carrying Amount, Trade names (indefinite-lived)	299,271	289,121
Total, Trade names (indefinite-lived)	240,338	230,188
Gross Carrying Amount, Total	1,323,534	1,264,334
Accumulated Impairment Charge, Total	(63,767)	(63,767)
Total	586,032	593,975
Customer relationships
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	807,766	762,516
Accumulated Amortization	(482,594)	(427,211)
Accumulated Impairment Charge	(4,834)	(4,834)
Total	320,338	330,471
Developed technology/Vendor network
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	95,661	95,661
Accumulated Amortization	(78,788)	(74,238)
Accumulated Impairment Charge	0	0
Total	16,873	21,423
Trade names (finite-lived)
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	35,991	33,791
Accumulated Amortization	(27,800)	(25,690)
Accumulated Impairment Charge	0	0
Total	8,191	8,101
Contract backlog
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	84,845	83,245
Accumulated Amortization	(84,553)	(79,453)
Accumulated Impairment Charge	0	0
Total	$ 292	$ 3,792

Goodwill, Identifiable Intang_6

Goodwill, Identifiable Intangible Assets, And Other Long-Lived Assets - Schedule of Expected Amortization Expense (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2024	$ 63,873
2025	62,369
2026	55,782
2027	42,583
2028	33,818
Thereafter	87,269
Total	$ 345,694

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)			12 Months Ended
Debt - Narrative (Details) - USD ($)	Dec. 20, 2023	Mar. 02, 2020	Dec. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Letters of credit outstanding (in US dollars)			$ 116,700,000	$ 71,300,000
2020 Term Loan
Line of Credit Facility [Line Items]
Term Loan (in US dollars)		$ 300,000,000		242,813,000
2020 Credit Agreement
Line of Credit Facility [Line Items]
Credit agreement, initiation date		Mar. 02, 2020
2023 Credit Agreement
Line of Credit Facility [Line Items]
Credit agreement, initiation date	Dec. 20, 2023
Expiration date of credit agreement			Dec. 20, 2028
Debt issuance costs	$ 3,400,000
2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Interest rate description			At the Company’s election, borrowings under the 2023 Revolving Credit Facility bear interest at either: (1) a base rate plus a margin of 0.125% to 0.875%, based on certain financial tests, or (2) a rate equal to the secured overnight financing rate as administered by the Federal Reserve Bank of New York for the applicable tenor plus 0.10% (“Adjusted Term SOFR”) plus a margin of 1.125% to 1.875%, based on certain financial tests. The base rate is determined by the greater of: (a) the prime commercial lending rate announced by Bank of Montreal from time to time, (b) the federal funds effective rate, plus 1/2 of 1.00%, (c) Adjusted Term SOFR for a one-month tenor, plus 1.00%, or (d) 0.00%.
Base Rate \| Minimum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			0.125%
Base Rate \| Maximum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			0.875%
SOFR \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			0.10%
Adjusted Term SOFR \| Minimum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			1.125%
Adjusted Term SOFR \| Maximum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			1.875%
Credit Agreement Base Rate, Adjusted Term SOFR One Month Tenor Rate \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			1%
Credit Agreement, 0% Base Rate \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			0%
Credit Agreement Base Rate, Federal Funds Rate \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate			0.50%
Revolving Credit Facility \| 2020 Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity (in US dollars)		$ 1,300,000,000
Borrowings under revolving credit facility (in US dollars)				$ 0
Revolving Credit Facility \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity (in US dollars)	$ 1,300,000,000
Increase in borrowing capacity (in US dollars)			$ 900,000,000
Letters of credit maximum borrowing capacity (in US dollars)			600,000,000
Borrowings under revolving credit facility (in US dollars)			$ 0
Commitment fee percentage of unused amount			0.125%
Revolving Credit Facility \| Minimum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage of unused amount			0.125%
Letter of credit fees			0.85%
Revolving Credit Facility \| Maximum \| 2023 Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage of unused amount			0.25%
Letter of credit fees			1.875%

Debt - Schedule Of Debt (Detail

Debt - Schedule Of Debt (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Mar. 02, 2020
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ (2,080,000)
Finance lease liabilities	$ 5,303,000	6,459,000
Total debt		247,192,000
Less: current maturities	2,465,000	15,567,000
Total long-term debt	$ 2,838,000	231,625,000
2020 Term Loan
Debt Instrument [Line Items]
Term Loan		$ 242,813,000	$ 300,000,000

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Assets And Liabilities Carried At Fair Value Measured On A Recurring Basis) (Details) - USD ($) $ in Thousands		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Restricted cash				$ 600		$ 1,200	$ 700
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		$ 789,750	[1]	456,439	[2]
Deferred compensation plan assets	[3]	47,315		36,882
Restricted cash	[4]			629
Total		837,065		493,950
Fair Value, Measurements, Recurring \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		789,750	[1]	456,439	[2]
Deferred compensation plan assets	[3]	47,315		36,882
Restricted cash	[4]			629
Total		837,065		493,950
Fair Value, Measurements, Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		0	[1]	0	[2]
Deferred compensation plan assets	[3]	0		0
Restricted cash	[4]			0
Total		0		0
Fair Value, Measurements, Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		0	[1]	0	[2]
Deferred compensation plan assets	[3]	0		0
Restricted cash	[4]			0
Total		0		0
Money Market Funds \| Fair Value, Measurements, Recurring \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		$ 497,300		$ 209,400

[1] Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2023, we had $497.3 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. Cash and cash equivalents consist of deposit accounts and money market funds with original maturity dates of three months or less, which are Level 1 assets. At December 31, 2022, we had $209.4 million in money market funds. From time to time, we have cash balances in certain of our domestic bank accounts that exceed federally insured limits. Deferred compensation plan assets are classified as “Other assets” in the Consolidated Balance Sheets. Restricted cash is classified as “Prepaid expenses and other” in the Consolidated Balance Sheets. Restricted cash primarily represents cash held in account for use on customer contracts.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Income tax provision	$ 239,524	$ 152,628	$ 145,602
Income tax rates on income before income taxes	27.50%	27.30%	27.50%
Cash and cash equivalents	$ 789,750	$ 456,439
Deferred tax liabilities, net	56,639	61,563
Valuation allowance for deferred tax assets	4,385	3,580
Other long-term obligations
Operating Loss Carryforwards [Line Items]
Deferred tax liabilities, net	56,600	$ 61,600
Non-US [Member] \| Subsidiaries [Member]
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries	167,300
Cash and cash equivalents	$ 135,000

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
United States	$ 844,002	$ 523,273	$ 497,421
Foreign	28,851	35,477	31,882
Income before income taxes	$ 872,853	$ 558,750	$ 529,303

Income Taxes - Schedule of In_2

Income Taxes - Schedule of Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Federal provision	$ 187,463	$ 100,707	$ 95,782
State and local provision	62,316	36,547	35,883
Foreign provision	6,396	4,891	4,420
Current income tax provision	256,175	142,145	136,085
Deferred (benefit) provision	(16,651)	10,483	9,517
Income tax provision	$ 239,524	$ 152,628	$ 145,602

Income Taxes - Schedule of U.S.

Income Taxes - Schedule of U.S. Statutory Income Tax Rate Rec (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Federal income taxes at the statutory rate	$ 183,230	$ 117,338	$ 111,118
State and local income taxes, net of federal tax benefits	46,752	29,519	31,257
Permanent differences	9,513	5,261	5,316
Foreign income taxes (including UK statutory rate changes)	640	(155)	(2,241)
Other	(611)	665	152
Income tax provision	$ 239,524	$ 152,628	$ 145,602

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred income tax assets:
Insurance liabilities	$ 59,667	$ 57,278
Operating lease liabilities	92,410	78,391
Deferred compensation	54,313	40,682
Other (including liabilities and reserves)	40,110	35,584
Total deferred income tax assets	246,500	211,935
Valuation allowance for deferred tax assets	(4,385)	(3,580)
Net deferred income tax assets	242,115	208,355
Deferred income tax liabilities:
Goodwill and identifiable intangible assets	(165,073)	(153,767)
Operating lease right-of-use assets	(85,883)	(73,134)
Depreciation of property, plant, and equipment	(30,075)	(28,435)
Pension asset	(4,660)	(4,082)
Other	(13,063)	(10,500)
Total deferred income tax liabilities	(298,754)	(269,918)
Net deferred income tax liabilities	$ (56,639)	$ (61,563)

Common Stock (Details)

Common Stock (Details) - USD ($)	3 Months Ended		12 Months Ended			147 Months Ended
Common Stock (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023
Equity, Class of Treasury Stock [Line Items]
Common stock, outstanding (in shares)		47,047,265	47,047,265	47,666,725		47,047,265
Dividends declared per common share (in US dollars per share)		$ 0.18	$ 0.69	$ 0.54	$ 0.52
Stock repurchase, authorized amount (in US dollars)		$ 2,150,000,000	$ 2,150,000,000			$ 2,150,000,000
Number of shares repurchased (in shares)			800,000			25,800,000
Stock repurchased (in US dollars)			$ 128,736,000	$ 660,609,000	$ 195,546,000	$ 1,890,000,000
Remaining authorized repurchase amount (in US dollars)		261,100,000	261,100,000			261,100,000
Subsequent Event [Member]
Equity, Class of Treasury Stock [Line Items]
Dividends declared per common share (in US dollars per share)	$ 0.25
Treasury stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchased (in US dollars)			128,736,000	$ 660,609,000	$ 195,546,000
Excise tax payable, current		$ 1,000,000	$ 1,000,000			$ 1,000,000

Share-Based Compensation Plan_2

Share-Based Compensation Plans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under share-based compensation plan (in shares)	3,250,000
Shares available for grant or issuance under share-based compensation plan (in shares)	692,720
Compensation expense to be recognized	$ 11,400
Maximum vesting period	3 years
Tax benefit from issuance of stock	$ 3,300	$ 3,900	$ 2,600
Excess tax benefit from share-based compensation	1,719	1,654	828
Awards of Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 13,700	$ 12,100	$ 11,100
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance deferral period	10 years
Restricted Stock Units (RSUs) \| Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested, but issuance deferred (in shares)	34,196
Restricted Stock Units (RSUs) \| Former employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested, but issuance deferred (in shares)	6,086
Employee Stock Purchase Plan (in shares)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under share-based compensation plan (in shares)	3,000,000

Share-Based Compensation Plan_3

Share-Based Compensation Plans - Schedule of activity of restricted stock units (Details) - Restricted Stock Units (RSUs) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Beginning Balance	317,594	404,468	397,918
Weighted Average Price, Beginning Balance (in dollars per share)	$ 100.83	$ 79.16	$ 73.16
Shares, Granted	103,024	107,621	129,859
Weighted Average Price, Granted (in dollars per share)	$ 156.06	$ 123.52	$ 96.32
Shares, Forfeited	(3,018)	(4,665)	(2,242)
Weighted Average Price, Forfeited (in dollars per share)	$ 118.59	$ 105.88	$ 78.86
Shares, Vested	(122,751)	(189,830)	(121,067)
Weighted Average Price, Vested (in dollars per share)	$ 90.38	$ 67.40	$ 77.86
Shares, Ending Balance	294,849	317,594	404,468
Weighted Average Price, Ending Balance (in dollars per share)	$ 124.30	$ 100.83	$ 79.16

Defined Benefit Plans - Narrati

Defined Benefit Plans - Narrative (Details) $ in Thousands	12 Months Ended
Defined Benefit Plans - Narrative (Details) $ in Thousands	Dec. 31, 2023 USD ($) plan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of plans \| plan	3
Benefit obligation	$ 6,300	$ 6,700
Fair value of plan assets	$ 5,100	$ 4,900
Discount rate		4.80%
Annual rate of return on plan assets	7%	7%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.75%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.20%
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Funded status of UK Plan	$ 18,980	$ 16,328
Annual rate of inflation	2.80%	2.80%
Average life expectancy	23 years
Reclassification adjustment from AOCI, net of income taxes	$ 2,000	$ 1,600	$ 2,900
Estimated unrecognized loss that will be amortized from AOCI, net of income taxes	2,000
Future estimated employer contributions to be paid next year	600
Benefit obligation	204,097	193,956	349,147
Fair value of plan assets	$ 223,077	$ 210,284	$ 356,532
Discount rate	4.80%	5%
Annual rate of return on plan assets	5.70%	3.90%	3.90%
Other assets \| United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Funded status of UK Plan	$ 19,000	$ 16,300

Defined Contribution Plans - Na

Defined Contribution Plans - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Contribution Plan Disclosure [Line Items]
Expense recognized	$ 36.7	$ 35	$ 33
Supplemental matching	10.2	9.2	7.7
United Kingdom Subsidiary
Defined Contribution Plan Disclosure [Line Items]
Expense recognized	$ 7.4	$ 7.3	$ 8.3

Retirement Plans - Schedule of

Retirement Plans - Schedule of Changes in Benefit Obligations and Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 6,700
Benefit obligation at end of year	6,300	$ 6,700
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	4,900
Fair value of plan assets at end of year	5,100	4,900
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	193,956	349,147
Interest cost	9,722	5,693	$ 5,326
Actuarial loss (gain)	651	(116,372)
Benefits paid	(10,411)	(11,095)
Foreign currency exchange rate changes	10,179	(33,417)
Benefit obligation at end of year	204,097	193,956	349,147
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	210,284	356,532
Actual return (loss) on plan assets	10,563	(105,544)
Employer contributions	1,564	4,875
Benefits paid	(10,411)	(11,095)
Foreign currency exchange rate changes	11,077	(34,484)
Fair value of plan assets at end of year	223,077	210,284	$ 356,532
Funded status at end of year	$ 18,980	$ 16,328

Retirement Plans - Schedule o_2

Retirement Plans - Schedule of Weighted Average Assumptions Used To Calculate Benefit Obligations (Details)	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Discount rate		4.80%
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.80%	5%

Components Of Net Periodic Pens

Components Of Net Periodic Pension Cost (Income) (Details) - United Kingdom Subsidiary - UK Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 9,722	$ 5,693	$ 5,326
Expected return on plan assets	(11,417)	(12,088)	(12,726)
Amortization of unrecognized loss	2,611	2,073	3,642
Net periodic pension cost (income)	$ 916	$ (4,322)	$ (3,758)

Retirement Plans - Schedule o_3

Retirement Plans - Schedule of Weighted Average Assumptions Used To Calculate Net Periodic Pension Costs (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Annual rate of return on plan assets	7%	7%
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5%	1.80%	1.40%
Annual rate of return on plan assets	5.70%	3.90%	3.90%

Retirement Plans - Schedule o_4

Retirement Plans - Schedule of Net Periodic Benefit Cost Not yet Recognized (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Unrecognized actuarial losses	$ 82,344	$ 79,313

Retirement Plans - Schedule o_5

Retirement Plans - Schedule of Weighted Average Assets Allocation and Weighted Average Target Allocation (Details) - United Kingdom Subsidiary - UK Plan	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	100%	100%
Asset Allocation	100%	100%
Debt
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	90%	75%
Asset Allocation	87.10%	80.70%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	0%	15%
Asset Allocation	3.90%	9.40%
Real estate
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	10%	10%
Asset Allocation	9%	9.90%

Retirement Plans - Schedule o_6

Retirement Plans - Schedule of Plan Assets Fair Value Hierarchy (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 5,100	$ 4,900
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		223,077	210,284	$ 356,532
United Kingdom Subsidiary \| UK Plan \| Total plan assets in fair value hierarchy
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		117,235	89,446
United Kingdom Subsidiary \| UK Plan \| Total plan assets in fair value hierarchy \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		8,797	19,829
United Kingdom Subsidiary \| UK Plan \| Total plan assets in fair value hierarchy \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		108,438	69,617
United Kingdom Subsidiary \| UK Plan \| Total plan assets in fair value hierarchy \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Corporate debt funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		44,504	23,998
United Kingdom Subsidiary \| UK Plan \| Corporate debt funds \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Corporate debt funds \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		44,504	23,998
United Kingdom Subsidiary \| UK Plan \| Corporate debt funds \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Government bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		63,934	45,619
United Kingdom Subsidiary \| UK Plan \| Government bond funds \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Government bond funds \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		63,934	45,619
United Kingdom Subsidiary \| UK Plan \| Government bond funds \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		8,797	19,829
United Kingdom Subsidiary \| UK Plan \| Cash and cash equivalents \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		8,797	19,829
United Kingdom Subsidiary \| UK Plan \| Cash and cash equivalents \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Cash and cash equivalents \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
United Kingdom Subsidiary \| UK Plan \| Debt funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	$ 85,786	$ 99,990
Fair value of plan assets by hierarchy and NAV [Extensible Enumeration]		Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]
United Kingdom Subsidiary \| UK Plan \| Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	$ 20,056	$ 20,848
Fair value of plan assets by hierarchy and NAV [Extensible Enumeration]		Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]

[1] Certain investments measured using net asset value (“NAV”) as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the total fair value of plan assets. NAV is determined by the respective fund manager based on the fair value of the underlying assets held by the fund, less its liabilities, divided by the number of units outstanding.

Retirement Plans - Schedule o_7

Retirement Plans - Schedule of Expected Benefit Payments (Details) - United Kingdom Subsidiary - UK Plan $ in Thousands	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
2024	$ 10,736
2025	11,185
2026	11,689
2027	12,079
2028	12,598
Succeeding five years	$ 67,955

Multiemployer Plans - Narrative

Multiemployer Plans - Narrative (Details)	12 Months Ended
Multiemployer Plans - Narrative (Details)	Dec. 31, 2023 USD ($) plan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Multiemployer Plans [Line Items]
Withdrawal liability	$ 0	$ 0	$ 0
Multiemployer Plans, Postretirement Benefit
Multiemployer Plans [Line Items]
Contribution increase due to acquisition	14,400,000
Contributions	243,500,000	213,700,000	178,400,000
Multiemployer Plans, Pension
Multiemployer Plans [Line Items]
Contribution increase due to acquisition	8,000,000
Contributions	$ 258,829,000	$ 236,165,000	$ 221,081,000
Multiemployer Plans, Pension \| Minimum
Multiemployer Plans [Line Items]
Number of plans \| plan	200
Contributions	$ 2,000,000
Red Zone \| Multiemployer Plans, Pension \| Minimum
Multiemployer Plans [Line Items]
Contributions	500,000
Orange or Yellow Zones \| Multiemployer Plans, Pension \| Minimum
Multiemployer Plans [Line Items]
Contributions	$ 1,000,000

Retirement Plans - Schedule o_8

Retirement Plans - Schedule of Multiemployer Plans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Multiemployer Plans [Line Items]
EIN		11-2125338
Expense recognized		$ 36,700	$ 35,000	$ 33,000
Multiemployer Plans, Pension
Multiemployer Plans [Line Items]
Contributions		$ 258,829	$ 236,165	221,081
Multiemployer Plans, Pension \| National Automatic Sprinkler Industry Pension Fund
Multiemployer Plans [Line Items]
EIN		52-6054620
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 25,559	$ 21,583	20,987
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| National Electrical Benefit Fund
Multiemployer Plans [Line Items]
EIN		53-0181657
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 18,128	$ 15,192	12,310
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| United Association National Pension Fund
Multiemployer Plans [Line Items]
EIN		52-6152779
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 16,815	$ 15,288	14,723
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Sheet Metal Workers National Pension Fund
Multiemployer Plans [Line Items]
EIN		52-6112463
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 10,797	$ 9,505	10,307
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Central Pension Fund of the IUOE & Participating Employers
Multiemployer Plans [Line Items]
EIN		36-6052390
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 8,573	$ 7,651	6,627
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Electrical Workers Local No. 26 Pension Trust Fund
Multiemployer Plans [Line Items]
EIN		52-6117919
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 8,283	$ 7,844	9,346
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Pension, Hospitalization & Benefit Plan of the Electrical Industry-Pension Trust Account
Multiemployer Plans [Line Items]
EIN		13-6123601
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 7,198	$ 8,122	7,355
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Plumbers Pipefitters & Mechanical Equipment Service Local Union 392 Pension Plan
Multiemployer Plans [Line Items]
EIN		31-0655223
Pension Plan Number		001
Zone Status	[1]	Red	Red
FIP/RP Status		Implemented
Contributions		$ 7,010	$ 7,674	7,110
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Electrical Workers Pension Plan Local 103 IBEW
Multiemployer Plans [Line Items]
EIN		04-6063734
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 6,537	$ 2,900	0
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Northern California Pipe Trades Pension Plan
Multiemployer Plans [Line Items]
EIN		94-3190386
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 6,317	$ 3,238	2,663
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Edison Pension Plan
Multiemployer Plans [Line Items]
EIN		93-6061681
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 5,840	$ 5,325	4,229
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Sheet Metal Workers Pension Plan of Northern California
Multiemployer Plans [Line Items]
EIN		51-6115939
Pension Plan Number		001
Zone Status	[1]	Red	Red
FIP/RP Status		Implemented
Contributions		$ 5,738	$ 6,074	7,850
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| San Diego Electrical Pension Plan
Multiemployer Plans [Line Items]
EIN		95-6101801
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 5,511	$ 4,258	4,068
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Heating, Piping & Refrigeration Pension Fund
Multiemployer Plans [Line Items]
EIN		52-1058013
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 5,315	$ 4,625	5,591
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Pipefitters Union Local 537 Pension Fund
Multiemployer Plans [Line Items]
EIN		51-6030859
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 5,179	$ 5,039	5,922
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Southern California Pipe Trades Retirement Fund
Multiemployer Plans [Line Items]
EIN		51-6108443
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 4,657	$ 4,650	6,272
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Electrical Contractors Association of the City of Chicago Local Union 134, IBEW Joint Pension Trust of Chicago Pension Plan 2
Multiemployer Plans [Line Items]
EIN		51-6030753
Pension Plan Number		002
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 4,432	$ 3,516	4,225
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| IBEW Local 701 Pension Fund
Multiemployer Plans [Line Items]
EIN		36-6455509
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,989	$ 2,625	1,276
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Eighth District Electrical Pension Fund
Multiemployer Plans [Line Items]
EIN		84-6100393
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,844	$ 3,339	3,298
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Southern California IBEW-NECA Pension Trust Fund
Multiemployer Plans [Line Items]
EIN		95-6392774
Pension Plan Number		001
Zone Status	[1]	Yellow	Yellow
FIP/RP Status		Implemented
Contributions		$ 3,801	$ 4,287	4,876
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| IBEW Local No. 82 Pension Plan
Multiemployer Plans [Line Items]
EIN		31-6127268
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,701	$ 2,549	956
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Sheet Metal Workers Pension Plan of Southern California, Arizona & Nevada
Multiemployer Plans [Line Items]
EIN		95-6052257
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,399	$ 2,921	3,322
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Kern County Electrical Workers Pension Fund
Multiemployer Plans [Line Items]
EIN		95-6123049
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,299	$ 1,542	1,167
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| U.A. Local 393 Pension Trust Fund Defined Benefit
Multiemployer Plans [Line Items]
EIN		94-6359772
Pension Plan Number		002
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,263	$ 3,517	3,507
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Arizona Pipe Trades Pension Trust Fund
Multiemployer Plans [Line Items]
EIN		86-6025734
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 3,048	$ 2,940	2,020
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Joint Pension Fund of Local Union No. 102
Multiemployer Plans [Line Items]
EIN		22-1615726
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,868	$ 1,762	1,531
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Plumbers & Steamfitters Local 486 Pension Fund
Multiemployer Plans [Line Items]
EIN		52-6124449
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,828	$ 1,599	1,351
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Plumbers & Pipefitters Local No. 189 Pension Fund
Multiemployer Plans [Line Items]
EIN		31-0894807
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,557	$ 1,272	596
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Local No. 697 IBEW and Electrical Industry Pension Fund
Multiemployer Plans [Line Items]
EIN		51-6133048
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,528	$ 2,287	1,753
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| U.A. Plumbers Local 24 Pension Fund
Multiemployer Plans [Line Items]
EIN		22-6042823
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,295	$ 1,819	2,270
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| NECA-IBEW Pension Trust Fund
Multiemployer Plans [Line Items]
EIN		51-6029903
Pension Plan Number		001
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,228	$ 3,034	2,491
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| IBEW 332 Pension Fund - Part A
Multiemployer Plans [Line Items]
EIN		94-2688032
Pension Plan Number		004
Zone Status	[1]	Green	Green
FIP/RP Status		NA
Contributions		$ 2,062	$ 4,177	2,339
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Plumbers & Pipefitters Local 162 Pension Fund
Multiemployer Plans [Line Items]
EIN		31-6125999
Pension Plan Number		001
Zone Status	[1]	Yellow	Yellow
FIP/RP Status		Implemented
Contributions		$ 1,243	$ 1,132	1,034
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Steamfitters Local Union No. 420 Pension Plan
Multiemployer Plans [Line Items]
EIN		23-2004424
Pension Plan Number		001
Zone Status	[1]	Red	Red
FIP/RP Status		Implemented
Contributions		$ 1,227	$ 1,018	677
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Boilermaker-Blacksmith National Pension Trust
Multiemployer Plans [Line Items]
EIN		48-6168020
Pension Plan Number		001
Zone Status	[1]	Red	Green
FIP/RP Status		Implemented
Contributions		$ 1,140	$ 6,434	3,479
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Plumbing & Pipe Fitting Local 219 Pension Fund
Multiemployer Plans [Line Items]
EIN		34-6682376
Pension Plan Number		001
Zone Status	[1]	Red	Red
FIP/RP Status		Implemented
Contributions		$ 919	$ 1,172	1,167
Contributions greater than 5%	[2]	true
Multiemployer Plans, Pension \| Carpenters Pension Trust Fund for Northern California
Multiemployer Plans [Line Items]
EIN		94-6050970
Pension Plan Number		001
Zone Status	[1]	Red	Red
FIP/RP Status		Implemented
Contributions		$ 610	$ 532	568
Contributions greater than 5%	[2]	false
Multiemployer Plans, Pension \| Other Multiemployer Pension Plans
Multiemployer Plans [Line Items]
Contributions		$ 56,091	$ 53,723	$ 51,818

[1]The zone status represents the most recent available information for the respective MEPP, which may be from 2022 or earlier for the 2023 year and from 2021 or earlier for the 2022 year. In general, plans with a “green” zone status have a funding ratio of at least 80%, plans with an “orange” or “yellow” zone status have a funding ratio of between 65% and less than 80%, and plans with a “red” zone status are less than 65% funded or are projected to have a funding deficiency in any of the next ten years.[2]This information was obtained from the respective plan’s Form 5500 (“Forms”) for the most current available filing. These dates may not correspond with our fiscal year contributions. The percentages of contributions are based upon disclosures contained in the plans’ Forms. Those Forms, among other things, disclose the names of individual participating employers whose annual contributions account for more than 5% of the aggregate annual amount contributed by all participating employers for a plan year. Accordingly, if the annual contribution of two or more of our subsidiaries each accounted for less than 5% of such contributions, but in the aggregate accounted for in excess of 5% of such contributions, that greater percentage is not available and therefore is not disclosed.

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) employee collective_bargaining_agreement
Loss Contingencies [Line Items]
Number of collective bargaining agreements that are national or regional in scope \| collective_bargaining_agreement	2
Minimum
Loss Contingencies [Line Items]
Number of employees \| employee	38,300
Number of collective bargaining agreements between our individual subsidiaries and local unions \| collective_bargaining_agreement	450
Surety Bond [Member]
Loss Contingencies [Line Items]
Estimated exposure, contracts with surety bonds \| $	$ 2,200
Estimated exposure, contracts with surety bonds, RPO percentage	25%
Surety bonds for insurance \| $	$ 48.1
Unionized Employees Concentration Risk [Member] \| Workforce Subject to Collective Bargaining Arrangements [Member]
Loss Contingencies [Line Items]
Percentage of employees represented by unions	60%

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Sublease rental income	$ 6.7	$ 3.8	$ 0.2

Leases - Schedule of Lease Asse

Leases - Schedule of Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets
Operating lease right-of-use assets	$ 310,498	$ 268,063
Finance lease right-of-use assets	4,932	6,117
Total lease assets	315,430	274,180
Current liabilities
Operating lease liabilities, current	75,236	67,218
Finance lease liabilities, current	2,465	2,652
Noncurrent liabilities
Operating lease liabilities, long-term	259,430	220,764
Finance lease liabilities, long-term	2,838	3,807
Total lease liabilities	$ 339,969	$ 294,441
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant, and equipment, net	Property, plant, and equipment, net
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current maturities of long-term debt and finance lease liabilities	Current maturities of long-term debt and finance lease liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term debt and finance lease liabilities	Long-term debt and finance lease liabilities

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Costs (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Finance lease expense:
Amortization expense		$ 2,816	$ 3,550	$ 4,255
Interest expense		175	178	255
Operating lease expense		93,158	77,143	70,928
Short-term lease expense	[1]	224,047	185,061	150,500
Variable lease expense		9,482	6,782	5,421
Total lease expense		$ 329,678	$ 272,714	$ 231,359

[1] Short-term lease expense includes both leases and rentals with initial terms of one year or less and predominantly represents equipment used on construction projects.

Leases - Schedule of Lease Term

Leases - Schedule of Lease Term and Discount Rate (Details)	Dec. 31, 2023	Dec. 31, 2022
Weighted-average remaining lease term:
Operating leases	5 years 8 months 12 days	5 years 10 months 24 days
Finance leases	2 years 10 months 24 days	2 years 10 months 24 days
Weighed-average discount rate:
Operating leases	4.11%	3.45%
Finance leases	3.57%	2.85%

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Paid For Amounts Included In The Measurement Of Lease Liabilities [Abstract]
Operating cash flows used for operating leases	$ 90,412	$ 74,927	$ 69,797
Operating cash flows used for finance leases	175	178	255
Financing cash flows used for finance leases	2,776	3,551	4,189
Right-of-use assets obtained in exchange for new operating lease liabilities	125,417	75,027	80,661
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 1,427	$ 2,209	$ 2,301

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Operating Leases
2024	$ 87,058
2025	69,127
2026	60,558
2027	47,961
2028	36,858
Thereafter	74,510
Total minimum lease payments	376,072
Less: Amount of lease payments representing interest	(41,406)
Present value of future minimum lease payments	334,666
Current portion of lease liabilities	75,236	$ 67,218
Noncurrent portion of lease liabilities	259,430	220,764
Finance Leases
2024	2,605
2025	1,533
2026	782
2027	389
2028	222
Thereafter	64
Total minimum lease payments	5,595
Less: Amount of lease payments representing interest	(292)
Present value of future minimum lease payments	5,303	6,459
Current portion of lease liabilities	2,465	2,652
Noncurrent portion of lease liabilities	$ 2,838	$ 3,807

Additional Cash Flow Informat_3

Additional Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash paid during the year for:
Interest	$ 16,246	$ 11,653	$ 5,259
Income taxes	$ 230,496	$ 168,732	$ 130,811

Segment Information (Details)

Segment Information (Details) $ in Thousands	12 Months Ended
Segment Information (Details) $ in Thousands	Dec. 31, 2023 USD ($) Company	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Revenues from unrelated entities	$ 12,582,873	$ 11,076,120	$ 9,903,580
Total revenues	12,582,873	11,076,120	9,903,580
Operating income (loss)	875,756	564,877	530,800
Impairment loss on long-lived assets	(2,350)	0	0
Net periodic pension (cost) income	(1,119)	4,311	3,625
Interest expense	(17,199)	(13,199)	(6,071)
Interest income	15,415	2,761	949
Income before income taxes	872,853	558,750	529,303
Capital expenditures	78,404	49,289	36,192
Depreciation and amortization of property, plant, and equipment	51,822	47,296	48,347
Contract assets	269,885	273,176	230,143
Contract liabilities	1,595,109	1,098,263	788,134
Total assets	$ 6,609,721	5,524,607	5,441,446
Number of operating subsidiaries \| Company	100
UNITED STATES
Segment Reporting Information [Line Items]
Revenues from unrelated entities	$ 12,146,450	10,599,042	9,393,629
Total revenues	12,146,450	10,599,042	9,393,629
Operating income (loss)	979,654	645,479	604,833
Capital expenditures	74,748	46,366	32,791
Depreciation and amortization of property, plant, and equipment	47,723	42,887	42,396
Contract assets	249,712	242,656	199,294
Contract liabilities	1,565,599	1,068,181	754,298
Total assets	5,440,862	4,672,469	4,206,824
UNITED STATES \| United States Electrical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	2,783,723	2,433,114	2,029,893
UNITED STATES \| United States Mechanical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	5,074,803	4,292,208	3,922,200
UNITED STATES \| United States Building Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	3,120,134	2,754,953	2,455,129
UNITED STATES \| United States Industrial Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	1,167,790	1,118,767	986,407
UNITED KINGDOM \| United Kingdom Building Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	436,423	477,078	509,951
Operating Segments [Member] \| UNITED STATES \| United States Electrical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	2,786,007	2,437,304	2,033,168
Total revenues	2,786,895	2,438,916	2,033,863
Operating income (loss)	230,640	148,728	169,355
Capital expenditures	6,929	11,228	4,985
Depreciation and amortization of property, plant, and equipment	8,402	7,543	7,229
Contract assets	73,464	75,603	48,382
Contract liabilities	399,550	271,161	200,966
Total assets	1,243,707	1,078,405	855,417
Operating Segments [Member] \| UNITED STATES \| United States Mechanical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	5,083,903	4,303,090	3,929,035
Total revenues	5,134,686	4,338,584	3,935,737
Operating income (loss)	530,644	330,325	312,809
Capital expenditures	37,543	11,930	10,108
Depreciation and amortization of property, plant, and equipment	12,503	11,492	11,354
Contract assets	97,252	99,632	89,102
Contract liabilities	925,481	594,453	386,518
Total assets	2,242,833	1,835,001	1,664,822
Operating Segments [Member] \| UNITED STATES \| United States Building Services
Segment Reporting Information [Line Items]
Total revenues	3,228,056	2,856,115	2,553,566
Operating income (loss)	182,995	146,639	124,335
Capital expenditures	19,843	13,303	11,539
Depreciation and amortization of property, plant, and equipment	15,672	12,964	12,090
Contract assets	61,867	56,694	42,818
Contract liabilities	223,202	184,821	150,333
Total assets	1,382,664	1,206,518	1,097,568
Operating Segments [Member] \| UNITED STATES \| United States Industrial Services
Segment Reporting Information [Line Items]
Total revenues	1,179,321	1,175,469	1,021,217
Operating income (loss)	35,375	19,787	(1,666)
Capital expenditures	10,433	9,905	6,159
Depreciation and amortization of property, plant, and equipment	11,146	10,888	11,723
Contract assets	17,129	10,727	18,992
Contract liabilities	17,366	17,746	16,481
Total assets	571,658	552,545	589,017
Operating Segments [Member] \| UNITED KINGDOM \| United Kingdom Building Services
Segment Reporting Information [Line Items]
Total revenues	436,423	477,078	509,951
Operating income (loss)	25,681	29,838	27,998
Capital expenditures	1,984	2,816	3,015
Depreciation and amortization of property, plant, and equipment	3,116	2,752	3,938
Contract assets	20,173	30,520	30,849
Contract liabilities	29,510	30,082	33,836
Total assets	277,066	255,547	241,740
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(127,229)	(110,440)	(102,031)
Capital expenditures	1,672	107	386
Depreciation and amortization of property, plant, and equipment	983	1,657	2,013
Total assets	891,793	596,591	992,882
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(182,508)	(210,042)	(150,754)
Intersegment Eliminations [Member] \| UNITED STATES \| United States Electrical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	(2,284)	(4,190)	(3,275)
Intersegment Eliminations [Member] \| UNITED STATES \| United States Mechanical Construction And Facilities Services
Segment Reporting Information [Line Items]
Revenues from unrelated entities	$ (9,100)	$ (10,882)	$ (6,835)

Segment Reporting (Details2)

Segment Reporting (Details2) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,721,959	$ 1,670,945	$ 1,631,699
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,710,457	1,659,635	1,617,762
Operating Segments [Member] \| UNITED STATES \| United States Electrical Construction And Facilities Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	290,896	302,448	237,766
Operating Segments [Member] \| UNITED STATES \| United States Mechanical Construction And Facilities Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	526,567	517,649	514,065
Operating Segments [Member] \| UNITED STATES \| United States Building Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	574,917	497,892	500,368
Operating Segments [Member] \| UNITED STATES \| United States Industrial Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	318,077	341,646	365,563
Operating Segments [Member] \| UNITED KINGDOM \| United Kingdom Building Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	9,761	10,320	11,402
Corporate, Non-Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,741	$ 990	$ 2,535

Subsequent Events (Details)

Subsequent Events (Details) $ in Millions	3 Months Ended
Subsequent Events (Details) $ in Millions	Jun. 30, 2024 USD ($)
2024Acquisitions \| Subsequent Event [Member]
Subsequent Event [Line Items]
Purchase price	$ 137

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Credit Losses - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		$ 22,382	$ 23,534	$ 18,031
Costs and Expenses		7,859	5,166	8,041
Deductions	[1]	(7,739)	(6,318)	(2,538)
Balance at End of Year		$ 22,502	$ 22,382	$ 23,534

[1]Deductions primarily represent uncollectible balances of accounts receivable written off, net of recoveries.