Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Schedule of Net Unfunded AFFA Liability, Net of Tax Schedule of Rollforward of Net Unfunded Amended and Restated Final Funding Agreement Liability [Table Text Block] Schedule of Rollforward of Net Unfunded Amended and Restated Final Funding Agreement Liability [Table Text Block] Weighted average common shares outstanding (Millions): Weighted Average Number of Shares Outstanding, Diluted [Abstract] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Range [Domain] Statistical Measurement [Domain] Title of 12(b) Security Title of 12(b) Security Subsequent Event Subsequent Event [Member] Asbestos Net Liability [Roll Forward] Asbestos Net Liability [Roll Forward] Asbestos Net Liability [Roll Forward] Document Fiscal Year Focus Document Fiscal Year Focus Acquisition related expenses Business Combination, Acquisition-Related Cost, Expense Adjustment to Compensation, Amount Adjustment to Compensation Amount Asbestos liability Asbestos Fund Liability Non Current Carrying value as of the balance sheet date of asbestos-related obligations incurred through that date and due after one year for estimated future asbestos claims. Segment Reporting [Abstract] Segment Reporting [Abstract] AZEK AZEK [Member] AZEK Common stock, Euro 0.59 par value, 2.0 billion shares authorized; 580,354,409 shares issued and outstanding at June 30, 2026 and 580,174,308 shares issued and outstanding at March 31, 2026 Common Stock, Value, Issued Cash paid for shares withheld for taxes Payment, Tax Withholding, Share-Based Payment Arrangement Accrued payroll and employee benefits Employee-related Liabilities, Current Schedule of Long-term Debt Instruments Schedule of Long-Term Debt Instruments [Table Text Block] Non-cash ROU assets obtained in exchange for new lease liabilities Right-Of-Use Asset Obtained In Exchange For Lease Liability Right-Of-Use Asset Obtained In Exchange For Lease Liability Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Derivative Instrument [Axis] Derivative Instrument [Axis] Movement in income tax payable Amount Of Deferred Tax Assets Applied To Income Tax Payable Portion of deferred income tax asset that becomes available to the Company as an Australian tax deduction resulting from the Company's previous contributions to AICF. Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Repayment of finance lease obligations Finance Lease, Principal Payments Technology Developed Technology Rights [Member] Deferred income taxes — Asbestos Deferred Tax Assets Net Asbestos Deferred Tax Assets Net Asbestos General Corporate and R&D Corporate And Reconciling Items [Member] Corporate And Reconciling Items Property, plant and equipment Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Asbestos Claims [Line Items] Asbestos Claims [Line Items] Asbestos Claims [Line Items] Investments [Domain] Investments [Domain] Accounts payable and accrued liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accounts Payable and Accrued Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accounts Payable and Accrued Liabilities Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Schedule of Reconciliation of Cash and Cash Equivalents - Asbestos Schedule of Cash and Cash Equivalents [Table Text Block] Property, Plant, and Equipment [Abstract] Property, Plant, and Equipment [Abstract] PEO Total Compensation Amount PEO Total Compensation Amount Common stock, par value (in Euros per share) Common Stock, Par or Stated Value Per Share Capital expenditures incurred but not yet paid Segment Reporting, Long-Lived Asset, Expenditure for Addition Intangible assets, net Intangible Asset, Excluding Goodwill, after Accumulated Amortization Notional amount Derivative, Notional Amount Basic (in shares) Basic common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Provision for obsolete finished goods and raw materials Inventory Valuation Reserves Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Customer Relationships Customer Relationships [Member] Comprehensive income, net of tax: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Asbestos liability Asbestos Fund Liability Current Carrying value as of the balance sheet date of asbestos-related obligations incurred through that date and due within one year for estimated future asbestos claims. Entity Address, City or Town Entity Address, City or Town Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Net Carrying Amount Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Accounts and other receivables, net Accounts and Other Receivables, Net, Current Term A-2 Facility, due 2030 Secured Debt A-2 [Member] Secured Debt A-2 Accumulated Amortization Intangible Asset, Finite-Lived, Accumulated Amortization Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Long-term debt, current portion Less current portion Long-Term Debt, Current Maturities Time Deposits Debt Securities, Held-to-Maturity, Restricted Subsequent Event Type [Axis] Subsequent Event Type [Axis] Senior Secured Notes Senior Secured Notes [Member] Senior Secured Notes Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Investment Income [Table] Investment Income [Table] Accounting Standards Issued But Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Other liabilities - current Business Combination, Recognized Liability Assumed, Other Liability, Current Capital expenditures incurred but not yet paid Capital Expenditures Incurred but Not yet Paid Land Land [Member] Schedule of Operating Segments Segment Reporting [Table Text Block] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total debt Long-Term Debt Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Property, Plant and Equipment Property, Plant, and Equipment [Text Block] Non-cash interest expense Noncash Interest Expense Noncash Interest Expense Income taxes payable Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Effect of foreign exchange Foreign Exchange Gain Loss In Asbestos Liability Foreign exchange gain or loss in the asbestos liability due to change in closing exchange rates between the currencies at the beginning and ending balance sheet dates. Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Security Exchange Name Security Exchange Name Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Operating lease liabilities Operating Lease, Liability, Current Schedule of Components of Property, Plant and Equipment Property, Plant, and Equipment [Table Text Block] Finance lease right-of-use assets Finance Lease, Right-of-Use Asset, after Accumulated Amortization Name Outstanding Recovery, Individual Name Income per share: Net income per share of common stock: Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Schedule of Basic and Dilutive Common Shares Outstanding Used in Determining Net Income Per Share Schedule of Weighted Average Number of Shares [Table Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Liabilities Trading Symbol Trading Symbol Net Unfunded AFFA Liability, net of tax Net Unfunded AFFA Liability, Net of Tax [Member] Net Unfunded AFFA Liability, Net of Tax [Member] Assets held for sale Asset, Held-for-Sale, Not Part of Disposal Group, Current Net Unfunded AFFA liability, net of tax, Beginning Balance Net Unfunded AFFA liability, net of tax, Ending Balance Asbestos Net Liability Net Tax Asbestos net liability in accordance with the Amended and Restated Final Funding Agreement, net of tax. Indefinite lived intangible assets other than goodwill Intangible Asset, Excluding Goodwill, Indefinite-Lived Purchases of property, plant and equipment Payments to Acquire Property, Plant, and Equipment Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Other Assets and Liabilities Other Assets And Liabilities [Member] Other Assets And Liabilities [Member] Income taxes payable Accrued Income Taxes, Current Schedule of Allocation of Purchase Price Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Company Selected Measure Name Company Selected Measure Name Reclassification from other comprehensive loss into net income, net of tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Schedule of Reconciliation of Restricted Cash and Restricted Cash - Asbestos Restrictions on Cash and Cash Equivalents [Table Text Block] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Other movements Asbestos Liability Other Changes Other movements in the asbestos liability, either increasing or decreasing the liability. Derivative, fixed interest rate Derivative, Fixed Interest Rate Schedule of Indefinite-Lived Intangible Assets [Table] Intangible Asset, Indefinite-Lived [Table] Non-Cash Investing and Financing Activities Noncash Investing and Financing Items [Abstract] Long-term debt, gross Long-Term Debt, Gross Credit Facility [Domain] Credit Facility [Domain] Schedule of Remaining Time Deposits Cash, Cash Equivalent, and Investment [Table Text Block] Compensation Amount Outstanding Recovery Compensation Amount Schedule of Indefinite-Lived Assets, Including Goodwill [Table] Schedule of Indefinite-Lived Assets, Including Goodwill [Table] Schedule of Indefinite-Lived Assets, Including Goodwill [Table] Individual: Individual [Axis] Indefinite-lived Intangible Assets [Line Items] Intangible Asset, Indefinite-Lived [Line Items] Insurance receivable — Asbestos Increase (Decrease) In Insurance Receivable Asbestos Increase decrease in insurance receivable asbestos. Diluted (in shares) Diluted common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Underlying Security Market Price Change Underlying Security Market Price Change, Percent Siding & Trim Siding & Trim Segment [Member] Siding & Trim Segment Deferred income taxes Deferred Income Taxes and Tax Credits Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Tax loss carry-forwards Operating Loss Carryforwards Asbestos adjustments Asbestos adjustments Asbestos Adjustments Comprised of changes in actuarial estimates received as of March 31 each year and the effect of foreign exchange movements in the asbestos related assets and liabilities which are denominated in Australian dollars. Income Tax Payable Income Tax Payable [Member] Income Tax Payable [Member] Interest rate swap, other current liabilities Derivative Liability, Subject to Master Netting Arrangement, before Offset Current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Senior Unsecured Notes Senior Unsecured Notes [Member] Senior Unsecured Notes Gross profit Gross Profit Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Other Other Intangible Assets [Member] Restricted Cash and Cash Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] 5.875% Senior notes due 2031 5.875% Senior Secured Notes Due 2031 [Member] 5.875% Senior Secured Notes Due 2031 Other accrued liabilities and interest Increase (Decrease) In Other Accrued Liabilities And Interest Increase (Decrease) In Other Accrued Liabilities And Interest Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Award Timing Predetermined Award Timing Predetermined [Flag] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Liability Awards Liability Awards [Member] Liability Awards [Member] Repayments of term loans Repayments of Unsecured Debt Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Credit Facilities Credit Facilities [Member] Credit Facilities Schedule Of Asbestos Claims [Line Items] Schedule Of Asbestos Claims [Line Items] Schedule Of Asbestos Claims [Line Items] 5.000% Senior notes due 2028 5.000% Senior Unsecured Notes Due 2028 [Member] 5.000% Senior Unsecured Notes Due 2028 Indefinite-lived Intangible Assets, Major Class Name [Domain] Intangible Asset, Indefinite-Lived, Class [Domain] Asbestos [Abstract] Asbestos Dilutive effect of stock awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Share-based compensation Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture All Executive Categories All Executive Categories [Member] Europe Europe Segment [Member] Europe Segment Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Repayments of revolving facility Repayments of Long-Term Lines of Credit Depreciation expense Depreciation Australia & New Zealand Australia & New Zealand Segment [Member] Australia & New Zealand Segment Antidilutive Securities [Axis] Antidilutive Securities [Axis] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Insurance Receivables Insurance Receivables [Member] Insurance Receivables [Member] Cash flow hedge gain (loss) to be reclassified during next 12 months, before tax Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Total consideration transferred Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Segment Information Segment Reporting [Text Block] Amount drawn under line of credit Long-Term Line of Credit Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Expiration Date Trading Arrangement Expiration Date Asbestos, net liability, beginning balance Asbestos net liability, ending balance Asbestos Net Liability Asbestos net liability in accordance with the Amended and Restated Final Funding Agreement. Net Unfunded AFFA Liability Net Unfunded AFFA Liability [Member] Net Unfunded AFFA Liability [Member] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Effects of exchange rate changes on cash and cash equivalents, restricted cash and restricted cash — Asbestos Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Time Deposits, January 27, 2027 Maturity Date Time Deposits, January 27, 2027 Maturity Date [Member] Time Deposits, January 27, 2027 Maturity Date Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Buildings Building [Member] Business Combination [Line Items] Business Combination [Line Items] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Asbestos Asbestos [Text Block] Represents disclosure of asbestos provision and related assets and liabilities. Letter of Credit and Bank Guarantees Letter of Credit and Bank Guarantees [Member] Letter of Credit and Bank Guarantees Common stock, shares authorized (in shares) Common Stock, Shares Authorized AICF operating costs paid - non claims-handling Asbestos Injuries Compensation Fund Operating Cost Paid Non Claim Handling Asbestos Injuries Compensation Fund operating cost paid non claim handling. Lives in Years Intangible Asset, Finite-Lived, Useful Life Accounts and other receivables Business Combination, Recognized Asset Acquired, Receivable, Current Accounts and other receivables Increase (Decrease) in Accounts and Other Receivables Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Exercise Price Award Exercise Price Segment Reporting [Line Items] Segment Reporting [Line Items] Net income Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Claims and handling costs paid — Asbestos Asbestos Net Claim Paid Adjustment Including Handling Costs Incurred Paid Asbestos Net Claim Paid Adjustment Including Handling Costs Incurred Paid Unrecognized compensation cost related to share-based compensation cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Proceeds from restricted investments — Asbestos Proceeds from restricted investments Asbestos Proceeds from restricted investments Asbestos Document Quarterly Report Document Quarterly Report Operating lease assets and liabilities, net Increase (Decrease) Operating Lease Assets and Liabilities, Net Increase (Decrease) Operating Lease Assets and Liabilities, Net Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Interest rate swap Interest Rate Swap [Member] Unamortized debt issuance costs Debt Issuance Costs, Net Time Deposits, October 16, 2026 Maturity Date Time Deposits, October 16, 2026 Maturity Date [Member] Time Deposits, October 16, 2026 Maturity Date Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Business Combination [Table] Business Combination [Table] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Adoption Date Trading Arrangement Adoption Date Interest rate (as percent) Debt Instrument, Interest Rate, Stated Percentage Total shareholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Debt issuance cost, writeoff Deferred Debt Issuance Cost, Writeoff Other assets - non-current Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Assets Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount James Hardie Common Shares issued (in shares) Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Line of credit, issued but undrawn Line Of Credit, Issued But Undrawn Line Of Credit, Issued But Undrawn Insider Trading Policies and Procedures [Line Items] Adjustments to Acquisition of The AZEK Company Goodwill, Measurement Period Adjustment Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Selling, general and administrative expenses Selling, General and Administrative Expense Business Acquisition, Acquiree [Domain] Business Combination [Domain] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Potential diluted common shares outstanding (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Changes in the Carrying Value of Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Less accumulated depreciation Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Payment received in accordance with AFFA Payments Received In Accordance With Amended And Restated Final Funding Agreement Payments received in accordance with amended and restated final funding agreement. Additional paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Business Acquisition [Axis] Business Combination [Axis] Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Income Statement [Abstract] Income Statement [Abstract] Shareholders’ equity: Equity, Attributable to Parent [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Restricted cash and cash equivalents — Asbestos Restricted Cash And Cash Equivalents Asbestos The carrying amounts of cash and cash equivalent items which are restricted to the settlement of asbestos claims and payments of the operating costs of the Asbestos Injuries Compensation Fund. Amounts are classified as current as they are highly liquid. Finance lease liabilities Finance Lease, Liability, Noncurrent Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of Intangible Asset, Finite-Lived Intangible Asset, Finite-Lived [Table Text Block] City Area Code City Area Code Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Lease expense Operating Lease, Right-of-Use Asset, Periodic Reduction Fair value of senior notes Debt Instrument, Fair Value Disclosure Name Forgone Recovery, Individual Name Estimated weighted average amortization, period of recognition Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Statement [Line Items] Statement [Line Items] Total assets Assets Operating Segments Operating Segments [Member] Interest, net Interest, net Interest Expense, Nonoperating Schedule of Share-Based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Recognized tax deduction Asbestos Recognized Tax Deduction The tax deduction relating to the AICF contribution. Total liabilities assumed Business Combination, Recognized Liability Assumed, Liability Share-Based Compensation Share-Based Payment Arrangement [Text Block] Change in component, net of tax OCI, before Reclassifications, Net of Tax, Attributable to Parent PEO PEO [Member] Total share-based compensation expense Share-Based Payment Arrangement, Expense Other liabilities Other Liabilities, Noncurrent Goodwill Amount of goodwill recognized Balance, beginning Balance, ending Goodwill Inventories Business Combination, Recognized Asset Acquired, Inventory, Current Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Subsequent Event Type [Domain] Subsequent Event Type [Domain] Retained Earnings Retained Earnings [Member] Operating lease liabilities Operating Lease, Liability, Noncurrent Revolving Facility Revolving Credit Facility [Member] Cash and cash equivalents Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Pension Actuarial Gain Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Debt issuance costs paid Payments of Debt Issuance Costs Diluted (in dollars per share) Earnings Per Share, Diluted Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Net cash (used in) provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Term A-1 Facility, due 2028 Secured Debt A-1 [Member] Secured Debt A-1 Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Amortization Intangible Asset, Finite-Lived, Amortization Expense Intangible Asset, Finite-Lived [Line Items] Intangible Asset, Finite-Lived [Line Items] Schedule of Post Acquisition and Pro Forma Business Combination, Pro Forma Information [Table Text Block] Proceeds from revolving facility Proceeds from Long-Term Lines of Credit Research and development expenses Research and development costs Research and Development Expense Total assets acquired Business Combination, Recognized Asset Acquired, Asset Asbestos, income tax payable, beginning balance Asbestos, income tax payable, ending balance Income Tax Payable Asbestos Australian tax deduction available to be taken by the Company resulting from the Company's previous contributions to AICF. Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Share-Based Payment Arrangement [Abstract] Net sales Revenue Revenue from Contract with Customer, Excluding Assessed Tax Property, plant and equipment, net Property, plant and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Net Investment Income [Line Items] Net Investment Income [Line Items] 6.125% Senior notes due 2032 6.125% Senior Secured Notes Due 2032 [Member] 6.125% Senior Secured Notes Due 2032 Inventories Inventory Disclosure [Text Block] Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Exercise of vested stock options Stock Issued During Period, Value, Stock Options Exercised Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Goodwill and Other Intangible Assets Intangible Asset and Goodwill [Text Block] Underlying Securities Award Underlying Securities Amount Interest Rate Debt Securities, Held-to-Maturity, Restricted, Interest Rate Debt Securities, Held-to-Maturity, Restricted, Interest Rate Revenues Revenue from Contract with Customer [Text Block] Issuance of common stock, net of shares withheld for taxes Stock Issued During Period, Value, New Issues Construction in progress Construction in Progress [Member] Inventories Increase (Decrease) in Inventories Accrued product warranties Product Warranty Accrual, Current Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary of Significant Accounting Policies [Line Items] Segment Reporting [Table] Segment Reporting [Table] Cash Flows from Investing Activities Cash Provided by (Used in) Investing Activity, Continuing Operation [Abstract] Weighted average interest rate of total debt Long-Term Debt, Weighted Average Interest Rate, at Point in Time Cash Flows from Operating Activities Cash Provided by (Used in) Operating Activity, Continuing Operation [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating income Operating income (loss) Operating Income (Loss) Current Fiscal Year End Date Current Fiscal Year End Date Insurance recoveries Insurance Recoveries Asbestos Adjustment The amount recovered from insurance related to asbestos claims. Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Derivative [Line Items] Derivative [Line Items] Business Combination Business Combination [Text Block] 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] Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Restricted short-term investments — Asbestos Restricted Short-Term Investments Asbestos Restricted Short-Term Investments Asbestos Restricted Cash and Investments Restricted Cash and Investments [Member] Restricted Cash and Investments [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Cash flow hedge gain (loss) to be reclassified during next 12 months, after tax Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months, Net Of Tax Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months, Net Of Tax Common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Finished goods Inventory, Finished Goods, Gross Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Equity Components [Axis] Equity Components [Axis] Income tax paid Income Tax Paid, after Refund Received Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity Interactive Data Current Entity Interactive Data Current Finance lease liabilities Finance Lease, Liability, Current Deferred income taxes Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Cash flow hedge gain (loss) reclassified to earnings Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Entity Small Business Entity Small Business Deferred Tax Assets Deferred Tax Assets [Member] Deferred Tax Assets [Member] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Termination Date Trading Arrangement Termination Date Acquired finite-lived intangible assets, weighted average useful life Intangible Asset, Finite-Lived, Acquired, Weighted-Average Amortization Period Property, Plant, and Equipment [Line Items] Property, Plant, and Equipment [Line Items] Intangible assets Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived 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 liabilities Other Liabilities, Current Other assets Other Assets, Noncurrent Cash Flows from Financing Activities Cash Provided by (Used in) Financing Activity, Continuing Operation [Abstract] Document Type Document Type Repurchased face amount Debt Instrument, Repurchased Face Amount Non-cash restructuring expenses Non-Cash Restructuring Expenses Non-Cash Restructuring Expenses Fair Value as of Grant Date Award Grant Date Fair Value Contribution to AICF Payment To Fund Under the terms of the Amended and Restated Final Funding Agreement (AFFA), a wholly owned Australian subsidiary (the Performing Subsidiary) has an obligation to make payments to the AICF on an annual basis. The amount of these annual payments is dependent on several factors, including the Company's free cash flow (as defined by the AFFA), actuarial estimations, actual claims paid, operating expenses of the AICF and the annual cash flow cap. Schedule of Intangible Asset, Indefinite-Lived Intangible Asset, Indefinite-Lived [Table Text Block] Organization and Significant Accounting Policies Significant Accounting Policies [Text Block] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Work-in-process Inventory, Work in Process, Gross Consolidation Items [Axis] Consolidation Items [Axis] Time Deposits, April 7, 2027 Maturity Date Time Deposits, April 7, 2027 Maturity Date [Member] Time Deposits, April 7, 2027 Maturity Date Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Purchase of restricted investments — Asbestos Purchase of restricted investments Asbestos Purchase of restricted investments Asbestos Income before income 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] Commitments and contingencies (Note 11) Commitments and Contingencies Gross Carrying Amount Intangible Asset, Finite-Lived, before Accumulated Amortization Property, plant and equipment, at cost Property, Plant, and Equipment, before Accumulated Depreciation, Depletion, and Amortization Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Machinery and equipment Machinery and Equipment [Member] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Goodwill [Roll Forward] Goodwill [Roll Forward] Liabilities and Shareholders’ Equity Liabilities and Equity [Abstract] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Trade names Trade Names Trade Names [Member] Inventories Total Inventory, Net Award Type [Domain] Award Type [Domain] Restricted cash and cash equivalents Restricted Cash And Cash Equivalents Excluding Amounts For Asbestos Claims Restricted cash and cash equivalents excluding amounts for asbestos claims. Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Supplemental Disclosure of Cash Flow Activities Supplemental Cash Flow Information [Abstract] PEO Name PEO Name Asbestos claims paid Asbestos Net Claim Paid Adjustment Asbestos liability net claims paid. Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Other expenses Segment Reporting, Other Segment Item, Amount Long-Lived Asset, Class [Axis] Long-Lived Asset, Class [Axis] Schedule Of Asbestos Claims [Table] Schedule Of Asbestos Claims [Table] Schedule Of Asbestos Claims [Table] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Reconciliation to Consolidated Net Income [Abstract] Reconciliation to Consolidated Net Income [Abstract] Reconciliation to Consolidated Net Income Cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Liability Class [Axis] Liability Class [Axis] Cash and cash equivalents, restricted cash and restricted cash — Asbestos at beginning of period Cash and cash equivalents, restricted cash and restricted cash — Asbestos at end of period Total Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule of Finite-Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Time Deposits, July 24, 2026 Maturity Date Time Deposits, July 24, 2026 Maturity Date [Member] Time Deposits, July 24, 2026 Maturity Date Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Restricted cash and cash equivalents Restricted Cash and Cash Equivalent, Current 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] Debt Instrument [Axis] Debt Instrument [Axis] Other liabilities - non-current Business Combination, Recognized Liability Assumed, Other Liability, Noncurrent Share-based compensation Share-Based Payment Arrangement, Noncash Expense Capitalized interest Interest Paid, Capitalized, Investing Activity Equity Awards Equity Awards [Member] Equity Awards [Member] Asbestos Liability Asbestos Liability [Member] Asbestos Liability [Member] Schedule of Components of Inventories Schedule of Inventory, Current [Table Text Block] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Schedule of Fair Value of Interest Rate Swap Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Basic (in dollars per share) Earnings Per Share, Basic Total current assets Assets, Current Range [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Long-term debt Total Long-term debt Long-Term Debt, Excluding Current Maturities Cost of goods sold Cost of Revenue Award Type [Axis] Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) 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] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Reclassification Reclassification, Comparability Adjustment [Policy Text Block] Derivative Contract [Domain] Derivative Contract [Domain] Foreign exchange impact Goodwill, Foreign Currency Translation, Gain (Loss) Equity Awards Adjustments Equity Awards Adjustments [Member] Total liabilities and shareholders’ equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Proceeds from senior secured notes Proceeds from Issuance of Senior Long-Term Debt Restructuring expenses Restructuring expenses Restructuring Charges Deferred income taxes Deferred Income Tax Assets, Net, Excluding Asbestos Deferred Income Tax Assets, Net, Excluding Asbestos Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Tabular List, Table Tabular List [Table Text Block] Other (income) expense, net Other income (expense), net Other Nonoperating Income (Expense) Debt Long-Term Debt [Text Block] Repayment of senior unsecured notes Repayments of Senior Debt Name Awards Close in Time to MNPI Disclosures, Individual Name Entity Address, Country Entity Address, Country 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] Long-Lived Asset, Class [Domain] Long-Lived Asset, Class [Domain] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Raw materials and supplies Inventory, Raw Materials and Supplies, Gross Property, Plant, and Equipment [Table] Property, Plant, and Equipment [Table] Adjustment to Compensation: Adjustment to Compensation [Axis] Accounts payable and accrued liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Deck, Rail & Accessories Deck, Rail & Accessories Segment [Member] Deck, Rail & Accessories Segment Contingent Shares Not Expected To Vest Contingent Shares Not Expected To Vest [Member] Contingent Shares Not Expected To Vest [Member] Name Measure Name Income Taxes Income Tax Disclosure [Text Block] Pay vs Performance Disclosure [Line Items] Asbestos, deferred tax assets, beginning balance Asbestos, deferred tax assets, beginning balance Deferred Tax Assets Net Asbestos Noncurrent Non current portion of Australian tax benefits as of the balance sheet date that will be available to the Company in relation to the Company's contributions to the AICF. Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Indefinite-lived Intangible Assets [Axis] Intangible Asset, Indefinite-Lived, Class [Axis] Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent Company Selected Measure Amount Company Selected Measure Amount Schedule of Indefinite-Lived Assets, Including Goodwill [Line Items] Schedule of Indefinite-Lived Assets, Including Goodwill [Line Items] [Line Items] for Schedule of Indefinite-Lived Assets, Including Goodwill [Table] Depreciation and amortization Depreciation, Depletion and Amortization Accrued product warranties Product Warranty Accrual, Noncurrent Entity Address, Address Line Three Entity Address, Address Line Three Entity Address, Address Line Two Entity Address, Address Line Two Current assets: Assets, Current [Abstract] Revenue Business Combination, Pro Forma Information, Pro Forma Revenue 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 Income tax expense Income Tax Expense (Benefit) Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Noncash Item [Abstract] AZEK Company Inc. AZEK Company Inc. [Member] AZEK Company Inc. Award Timing Method Award Timing Method [Text Block] Variable Interest Entities Consolidation, Policy [Policy Text Block] Net (decrease) increase in cash and cash equivalents, restricted cash and restricted cash — Asbestos 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] Deferred tax liabilities, net Business Combination, Recognized Liability Assumed, Deferred Tax Liability AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] 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] AICF Fund, contribution paid AICF Fund, Contribution Paid AICF Fund, Contribution Paid Restatement Determination Date: Restatement Determination Date [Axis] Proceeds from exercise of vested stock options Proceeds from Stock Options Exercised Schedule of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Interest rate swap, other non-current assets Derivative Asset, Subject to Master Netting Arrangement, before Offset Number of new claims Loss Contingency, New Claims Filed, Number AICF claims-handling costs incurred (paid) Asbestos Injuries Compensation Fund Claims Handling Costs Incurred (Paid) Asbestos injuries compensation fund claims handling costs incurred or paid. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Prepaid expenses and other current assets Business Combination, Recognized Asset Acquired, Prepaid Expense and Other Asset, Current Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]