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(in USD per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Materials and supplies Supplies Expense Insurance policy coverage, general and automobile liability losses Insurance Policy Coverage, General Liability And Automobile Liability Losses Represents commercial insurance umbrella policies that cover general liability and automobile liability losses above primary limits. Energy Savings Contracts Energy Savings Contracts [Member] Energy Savings Contracts [Member] Impairment of assets Asset, Impairment Loss Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Total adjustments Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Entity Interactive Data Current Entity Interactive Data Current Deferred income tax liability, net Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent RavenVolt RavenVolt, Inc. [Member] RavenVolt, Inc. Termination Date Trading Arrangement Termination Date Facility Solutions Facility Service Line [Member] Facility Service Line Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other noncurrent assets Other Assets, Noncurrent Document Type Document Type Purchase of businesses, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Gain on sale of assets Gain (Loss) on Disposition of Assets Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Amount 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Time to MNPI Disclosures [Table] Instruments Used to Collateralize Insurance Obligations, Type [Domain] Instruments Used to Collateralize Insurance Obligations, Type [Domain] Instruments Used to Collateralize Insurance Obligations, Type [Domain] Common Stock Common Stock [Member] Fair value of contingent consideration Contingent consideration Business Combination, Contingent Consideration, Liability Employee Severance Employee Severance [Member] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover page. Cover [Abstract] Insurance [Abstract] Insurance [Abstract] Derivative Contract [Domain] Derivative Contract [Domain] Term Loan Loans Payable [Member] Equity Awards Adjustments Equity Awards Adjustments [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Building & Energy Solutions Engineering And Infrastructure Service Line, Building And Energy Solutions [Member] Building & Energy Solutions [Member] Total liabilities and stockholders’ equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Current portion of debt, net Debt, Current Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Restructuring and related expenses Restructuring charges recognized Costs recognized Restructuring Charges Tabular List, Table Tabular List [Table Text Block] Insurance deposits Restricted Cash and Cash Equivalent, Noncurrent Right-of-use assets Increase (Decrease) In Operating Lease Right-Of-Use Asset Increase (Decrease) In Operating Lease Right-Of-Use Asset Other noncurrent liabilities Increase (Decrease) in Other Noncurrent Liabilities Total current portion of term loan, net Loans Payable, Current Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] General and administrative General and Administrative Expense Deferred consideration, number of installments Business Combination, Deferred Consideration, Number Of Installments Business Combination, Deferred Consideration, Number Of Installments Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Other significant segment items Segment Reporting, Other Disclosure [Abstract] Preferred stock, $0.01 par value; 500,000 shares authorized; none issued Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Asset Impairment Asset Impairment [Member] Asset Impairment Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Credit Facility [Axis] Credit Facility [Axis] RESTRUCTURING AND RELATED COSTS Restructuring and Related Activities Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Direct labor costs Cost, Direct Labor Name Measure Name INCOME TAXES Income Tax Disclosure [Text Block] Non-cash items Restructuring Reserve, Settled without Cash Trade accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Primary policy limit Workers Compensation, General Liability, And Other Insurable Risks, Insurance Policy Limit Represents the policy limit provided by the insurance program for workers' compensation, general liability, and other insurable risks. Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Aggregate purchase consideration Business Combination, Consideration Transferred Interest rate swaps Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Schedule of Insurance Related Balances and Activity Schedule Of Insurance Related Balances And Activity [Table Text Block] Schedule Of Insurance Related Balances And Activity [Table Text Block] Name Trading Arrangement, Individual Name Current portion of long-term debt Long-Term Debt, Current Maturities [Abstract] Selling Selling Expense Cash and cash equivalents Cash and Cash Equivalent Surety bonds and surety-backed letters of credit Surety Bonds And Surety-Backed Letters Of Credit [Member] Surety Bonds And Surety-Backed Letters Of Credit Company Selected Measure Amount Company Selected Measure Amount Distributions from unconsolidated affiliates Proceeds from Equity Method Investment, Distribution Depreciation and amortization Depreciation, Depletion and Amortization Number of industry groups Number Of Industry Groups Number Of Industry Groups Entity Address, Address Line Two Entity Address, Address Line Two Long-term debt Long-Term Debt, Excluding Current Maturities [Abstract] Term loan Term Loan [Member] Term Loan Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Parking and Transportation Facility Service Line, Parking And Transportation [Member] Facility Services, Parking and Transportation 2030 Long-Term Debt, Maturity, Year Five Current assets Assets, Current [Abstract] Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Income tax provision Income Tax Expense (Benefit) M&D Manufacturing And Distribution [Member] Operating expenses Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Net increase in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Unbilled trade receivables Contract With Customer, Asset, Unbilled Trade Receivables, Current Contract With Customer, Asset, Unbilled Trade Receivables, Current Discount accretion on insurance claims Accretion Expense Contract with Customer, Liabilities [Roll Forward] Contract with Customer, Liabilities [Roll Forward] Contract with Customer, Liabilities [Roll Forward] Deferred income tax liability Business Combination, Recognized Liability Assumed, Deferred Tax Liability Number of customers retained Business Combination, Contingent Consideration, Number Of Customers Retained Business Combination, Contingent Consideration, Number Of Customers Retained Net income Net income Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member] Restatement Determination Date: Restatement Determination Date [Axis] Interest rate swap liabilities Interest Rate Derivative Liabilities, at Fair Value Operations and Maintenance Engineering And Infrastructure Service Line, Operations And Maintenance [Member] Operations and Maintenance [Member] Impairment loss recorded on costs capitalized Capitalized Contract Cost, Impairment Loss Schedule of Contract Asset and Liability Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Trade accounts receivable and costs incurred in excess of amounts billed Increase (Decrease) in Receivables Tax to be reclassified during the next 12 months Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months, Tax Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months, Tax Insurance claims Increase (Decrease) in Self Insurance Reserve Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]