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Remaining Performance Obligation, Amount Current Fiscal Year End Date Current Fiscal Year End Date Equity-Based Incentive Grants Equity-Based Incentive Grants [Member] Equity-Based Incentive Grants Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Asia Asia [Member] PA Consulting Redeemable Noncontrolling Interests Business Combination [Text Block] Cumulative translation adjustments and other Noncontrolling Interest, Increase from Cumulative Translation Adjustment and Other Noncontrolling Interest, Increase from Cumulative Translation Adjustment and Other Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Dividend declared (in dollars 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] Service cost Defined Benefit Plan, Service Cost Thereafter Intangible Asset, Finite-Lived, Estimated Amortization Expense, after Year Five Noncontrolling interests - distributions and other Attribution of Preferred Dividend to Common Shareholders Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Restructuring costs Restructuring Costs Common stock, issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Professional Services and Employee Seperation Professional Services and Employee Separation [Member] Professional Services and Employee Separation Joint Ventures, VIEs and Other Investments Equity Method Investments and 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Change in Redemption Value Entity Small Business Entity Small Business Net Comprehensive Income Attributable to Jacobs Comprehensive Income (Loss), Net of Tax, Attributable to Parent Termination Date Trading Arrangement Termination Date Schedule of Cumulative Amounts Incurred for Restructuring and Other Activities Costs Schedule Of Cumulative Amounts Incurred For Restructuring And Other Activities Costs Table [Table Text Block] Schedule of cumulative amounts incurred for restructuring and other activities costs. Noncontrolling Interest [Table] Noncontrolling Interest [Table] PA Consulting Employees PA Consulting Employees [Member] PA Consulting Employees Net Loss Attributable to Jacobs from Discontinued Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Pension plan liability, net of deferred taxes Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] U.S tax unfavorable tax impacts Effective Income Tax Rate Reconciliation, Nondeductible Expense, Incentive Compensation, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, Incentive Compensation, Amount Total other 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Remaining Authorized, Amount Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from long-term borrowings Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Canada CANADA Consolidation Items Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Worley Stock Worley Stock [Member] Worley Stock [Member] Earnings from Continuing Operations Before Taxes Earnings from Continuing Operations Before Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Redeemable Noncontrolling interests redemption value adjustment (See Note 15- PA Consulting Redeemable Noncontrolling Interests) Temporary Equity, Accretion to Redemption Value, Adjustment Commitments and Contingencies Commitments and Contingencies Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Equity in earnings of operating ventures, net of return on capital distributions Net (loss) income from equity method investments Income (Loss) from Equity Method Investments Finite-lived Intangible Assets [Roll Forward] Intangible Asset, Finite-Lived [Roll Forward] Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Equity, Attributable to Noncontrolling Interest [Roll Forward] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Income Tax Benefit: Other Comprehensive Income (Loss), Tax Goodwill [Roll Forward] Goodwill [Roll Forward] LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Intangible Asset, Finite-Lived, Class Intangible Asset, Finite-Lived, Class [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) 1 [Member] London Interbank Offered Rate (LIBOR) 1 Trade Names Trade Names [Member] Redeemable Noncontrolling interests Temporary Equity, Carrying Amount, Attributable to Parent All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Net Earnings from continuing operations allocated to common stock for EPS calculation Undistributed Earnings (Loss) from Continuing Operations Available to Common Shareholders, Basic Fair Value and Fair Value Measurements Fair Value Disclosures [Text Block] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Voluntary and Involuntary Termination Terminations [Member] Terminations 5.375% Bonds, due 2036 5.375% Bonds [Member] 5.375% Bonds 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Ownership interest of employees (as a percent) Subsidiary, Ownership Percentage, Noncontrolling Owner PEO Name PEO Name Loss Before Taxes from Discontinued Operations Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Geographical [Axis] Geographical [Axis] Accrued liabilities Increase (Decrease) in Accrued Liabilities Contract liabilities Contract with Customer, Liability Gain/(Loss) on Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Professional Services Related to PA Consulting Transaction Professional Services Related To PA Consulting Transaction [Member] Professional Services Related To PA Consulting Transaction Customer Relationships, Contracts and Backlog Contracts And Backlog Intangible [Member] Contracts And Backlog Intangible PA Consulting PA Consulting [Member] PA Consulting Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Foreign currency translation adjustments and other Intangible Asset, Finite-Lived, Foreign Currency Translation Gain (Loss) Other deferred liabilities Deferred Long-Term Liability Charges Denominator for Basic and Diluted EPS: Denominator For Basic And Diluted Earnings Per Share [Abstract] Denominator for basic and diluted earnings per share. Payments and other Payments for Restructuring 4.75% Bonds, due 2031 4.75% Bonds [Member] 4.75% Bonds Accounts payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Base Rate Base Rate [Member] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] India INDIA Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Basic Net Loss from Discontinuing Operations Per Share (in dollars per share) Basic Net Loss from Discontinuing Operations Per Share (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Net Comprehensive Income of the Group Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Ownership percentage Equity Method Investment, Ownership Percentage Consideration paid in cash Payments to Acquire Businesses, Gross Stock based compensation Share-Based Payment Arrangement, Noncash Expense 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Revolving Credit Facility Revolving Credit Facility One Billion Six Hundred Million [Member] Revolving credit facility, one billion six hundred million. Disposal Group Name [Axis] Disposal Group Name [Axis] Repurchase of redeemable noncontrolling interests and related costs Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction Payments for Repurchase of Redeemable Noncontrolling Interest Operating Loss Disposal Group, Including Discontinued Operation, Operating Income (Loss) Investment, Name [Domain] Investment, Name [Domain] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Basic Earnings Per Share (in dollars per share) Earnings Per Share, Basic Common stock repurchases Payments for Repurchase of Common Stock Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Long-term debt Long-Term Debt, Excluding Current Maturities Discontinued net cash flows from operating activities Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax Award Type Award Type [Axis] Majority, after twelve months Majority, After Twelve Months [Member] Majority, After Twelve Months Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Equity method investment retained, shares owned after disposal (in shares) Discontinued Operation, Equity Method Investment Retained after Disposal, Shares Owned after Disposal Discontinued Operation, Equity Method Investment Retained after Disposal, Shares Owned after Disposal Schedule of Share Repurchases Class of Treasury Stock [Table Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Restructuring and Related Activities [Abstract] Restructuring and Related Activities [Abstract] Change in cash flow hedges, net of deferred taxes Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock Common Stock [Member] Amentum Holdings, Inc. Amentum Holdings, Inc. [Member] Amentum Holdings, Inc. Issuances of equity securities including shares withheld for taxes Stock Issued During Period, Value, Net of Shares Withheld for Taxes Stock Issued During Period, Value, Net of Shares Withheld for Taxes Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover page. Cover [Abstract] Sterling Overnight Interbank Average Rate (SONIA) Sterling Overnight Interbank Average Rate (SONIA) [Member] Sterling Overnight Interbank Average Rate (SONIA) Income Tax Benefit (Expense): Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosure [Abstract] Derivative Contract [Domain] Derivative Contract [Domain] Foreign currency translation adjustments and other Goodwill, Foreign Currency Translation, Gain (Loss) Equity Awards Adjustments Equity Awards Adjustments [Member] Step Up Date Axis [Axis] Step Up Date Axis [Axis] Step Up Date Axis Committed and Uncommitted Letter-of-Credit Facilities Committed And Uncommitted Letter Of Credit Facility [Member] Committed and Uncommitted Letter of Credit Facility [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Total liabilities and equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Noncontrolling interests Redeemable noncontrolling interest, beginning balance Redeemable noncontrolling interest, ending balance Equity, Attributable to Noncontrolling Interest Accrued Preferred Dividend to Preference Shareholders Temporary Equity, Dividends, Adjustment Discontinued operation, entitled to receive shares held in escrow (in shares) Discontinued Operation, Entitled to Receive Shares Held In Escrow Discontinued Operation, Entitled to Receive Shares Held In Escrow Segments Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Restructuring and other charges Net Charges Restructuring Charges Schedule of Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Tabular List, Table Tabular List [Table Text Block] Vesting [Axis] Vesting [Axis] Miscellaneous income (expense), net Other Nonoperating Income (Expense) Revenue Recognition Period [Domain] Revenue Recognition Period [Domain] Revenue Recognition Period [Domain] 2031 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Five Total Jacobs Stockholders’ Equity Parent [Member] 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three 2026 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Name Awards Close in Time to MNPI Disclosures, Individual Name Stockholders’ Equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] 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] Schedule of Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest [Table Text Block] Preferred stock, authorized (in shares) Preferred Stock, Shares Authorized Worley WorleyParsons Limited, ECR Business [Member] WorleyParsons Limited, ECR Business [Member] Receivables and contract assets Total receivables and contract assets, net Receivables, Net, Current Preferred stock, $1 par value, authorized - 1,000,000 shares; issued and outstanding - none Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Reclassifications from accumulated other comprehensive loss Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Net loss attributable to redeemable noncontrolling interests to Common Shareholders Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Share Repurchase Program [Axis] Share Repurchase Program [Axis] 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] Foreign Exchange Forward Foreign Exchange Forward [Member] Repurchase of redeemable noncontrolling interests Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Equity method investment retained after disposal, mark-to market losses Discontinued Operation, Equity Method Investment Retained after Disposal, Change in Fair Value, Realized Gain (Loss) Discontinued Operation, Equity Method Investment Retained after Disposal, Change in Fair Value, Realized Gain (Loss) Credit Facility [Axis] Credit Facility [Axis] Restructuring and Other Charges Restructuring and Related Activities Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Name Measure Name Income Taxes Income Tax Disclosure [Text Block] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Consideration transferred Business Combination, Consideration Transferred Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Numerator for Basic and Diluted EPS: Numerator For Basic And Diluted Earnings Per Share [Abstract] Numerator for basic and diluted earnings per share. Repayments of short-term borrowings Repayments of Short-Term Debt Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent (Gain) loss on investment in equity securities Debt and Equity Securities, Gain (Loss) Company Selected Measure Amount Company Selected Measure Amount Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Entity Address, Address Line Two Entity Address, Address Line Two Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Net Earnings of the Group Net Earnings of the Group Net Earnings of the Group Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Discontinued operation, working capital adjustment Discontinued Operation, Working Capital Adjustment Discontinued Operation, Working Capital Adjustment Current Assets: Assets, Current [Abstract] Non-PEO NEO Non-PEO NEO [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Income Tax Expense from Continuing Operations Income Tax Expense (Benefit) Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction Redeemable Noncontrolling Interests, Adjustment Redeemable Noncontrolling Interests, Adjustment Direct cost of contracts Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Net (decrease) increase in Cash and Cash Equivalents and Restricted Cash 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] Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Net Earnings Attributable to Jacobs Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Balance Sheet Location [Axis] Location, Statement of Financial Position, Balance [Axis] Disposals of property and equipment and other assets Proceeds from Sale of Property, Plant, and Equipment Statement [Table] Statement [Table] Net Loss of the Group from Discontinued Operations, net of tax Net Loss of the Group from Discontinued Operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Share-Based Payment Arrangement, Tranche Two Share-Based Payment Arrangement, Tranche Two [Member] Treasury Lock Treasury Lock [Member] Restatement Determination Date: Restatement Determination Date [Axis] Unsecured Revolving Credit Facility February 6, 2023 Unsecured Revolving Credit Facility February 6, 2023 [Member] Unsecured Revolving Credit Facility February 6, 2023 Schedule of Accumulated Other Comprehensive Loss After-Tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Cash contributions projected for the remainder of fiscal 2026 Expected Pension Contributions Expected Pension Contributions Term of derivative contract (in years/months) Derivative, Contract Term Interest income Investment Income, Interest Receivables and contract assets, net of contract liabilities Increase (Decrease) in Receivables Net Earnings Attributable to Jacobs from Continuing Operations Net Earnings Attributable to Jacobs from Continuing Operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Restructuring, Transaction and Other Charges Restructuring And Other Charges Restructuring and other charges. Use of Estimates and Assumptions Use Of Estimates And Assumptions Disclosure [Text Block] Use of estimates and assumptions disclosure. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]