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Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Concentration Risk Type [Axis] Concentration Risk Type [Axis] Revolving Loans and Letters of Credit Revolving Loans and Letters of Credit [Member] Revolving Loans and Letters of Credit Property and equipment, net Property, Plant and Equipment, Additions Restructuring and related costs Restructuring and related costs Restructuring Costs Amortization expense for 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Four Marketing Marketing Expense 2026 Finance Lease, Liability, to be Paid, Year One Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Operating leases Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Document Financial Statement Error Correction Document Financial Statement Error Correction [Flag] State income taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] Operating lease obligations Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] LoopNet LoopNet [Member] LoopNet Schedule of Components of Income Tax Expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Allowance for credit losses Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Accounts Receivable, Allowance for Credit Loss Plan Name [Axis] Plan Name [Axis] Operating lease costs: Operating Lease Cost [Abstract] Operating Lease Cost Property and Equipment, Net Property, Plant and Equipment, Policy [Policy Text Block] PEO PEO [Member] Proceeds from sale and settlement of investments and other assets Proceeds from Sale, Maturity and Collection of Investments UNITED STATES UNITED STATES Changes in operating assets and liabilities, net of acquisitions: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] DSU DSU [Member] DSU Increase (decrease) in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Property and equipment, net Deferred Tax Liabilities, Property, Plant and Equipment Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Michael Desmarais [Member] Michael Desmarais Retained Earnings Retained Earnings [Member] Income Tax Jurisdiction [Axis] Income Tax Jurisdiction [Axis] Cash, cash equivalents, and restricted cash at the beginning of period Cash, cash equivalents, and restricted cash at the end of period Total cash, cash equivalents, and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Acquired above-market leases Acquired above-market leases Above Market Leases [Member] Product and Service [Domain] Product and Service [Domain] Transaction costs Business Combination, Transaction Cost, Excluding Separately Recognized Transaction Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Parent Parent [Member] $77.57 - $91.98 Exercise Range 5 [Member] The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices. 2028 Lessor, Operating Lease, Payment to be Received, Year Three Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Business Combination [Table] Business Combination [Table] Aggregate notional amount Derivative, Notional Amount Organization, 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Revenue, remaining performance obligation, expected timing of satisfaction, period (in years) Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 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] $53.25 - $77.56 Exercise Range 4 [Member] The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices. Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Lease right-of-use assets ROU Assets Operating Lease, Right-of-Use Asset Income tax expense (percent) Effective Income Tax Rate Reconciliation, Percent Total operating lease costs Operating Lease, Cost Plan Name [Domain] Plan Name [Domain] Transaction cost, expense Business Combination, Acquisition-Related Cost, Expense Weighted-average-period expected to recognize the unrecognized compensation cost (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Exercise of stock options (in shares) Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Valuation allowance Deferred Tax Assets, Valuation Allowance Long-Lived Assets, Intangible Assets and Goodwill Goodwill and Intangible Assets, Policy [Policy Text Block] Buildings Buildings Building [Member] SEGMENT REPORTING Segment Reporting Disclosure [Text Block] Goodwill [Table] Goodwill [Table] Lease liabilities Increase (Decrease) In Lease Liability Increase (Decrease) In Lease Liability Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Federal Current Federal Tax Expense (Benefit) Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Consideration payable Business Combination, Contingent Consideration, Liability Accrued capital expenditures and non-cash landlord incentives Capital Expenditures Incurred but Not yet Paid and Noncash Landlord Incentives Capital Expenditures Incurred but Not yet Paid and Noncash Landlord Incentives Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Leases Lessee, Leases [Policy Text Block] Customer base amortization Amortization of Intangible Assets Indefinite-lived intangible assets, written off Indefinite-lived Intangible Assets, Written off Indefinite-lived Intangible Assets, Written off Deferred income taxes, net Deferred Income Tax Assets, Net Schedule of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Depreciation and amortization Depreciation, Depletion and Amortization Schedule of Property, Plant, and Equipment, Lessor Asset under Operating Lease Property, Plant, and Equipment, Lessor Asset under Operating Lease [Table Text Block] Statutory tax rate difference Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Present value of lease liabilities Finance Lease, Liability Arrangement Duration Trading Arrangement Duration Computer hardware and software Computer Equipment [Member] Segments [Axis] Segments [Axis] Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Accounts receivable Accounts Receivable, before Allowance for Credit Loss, Current Non-current portion Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Other operating activities, net Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item Thereafter Long-Term Debt, Maturity, after Year Five EMPLOYEE BENEFIT PLANS Share-Based Payment Arrangement [Text Block] Intangible assets Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Cash and cash equivalents Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent ASSETS Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Proceeds from exercise of stock options and employee stock purchase plan Proceeds From Exercise Of Stock Options and ESPP The cash inflow associated with the amount received from holders exercising their stock options and participants of employee stock purchase plans. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. 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Asset Acquisition [Line Items] Asset Acquisition [Line Items] Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Treasury stock, 7.1 million shares, cost basis at December 31, 2025 Treasury Stock, Value Nondeductible Compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Compensation, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, Compensation, Amount Defined Contribution Plan Disclosure [Line Items] Defined Contribution Plan Disclosure [Line Items] Foreign Foreign Tax Jurisdiction [Member] Auditor Firm ID Auditor Firm ID Segments [Domain] Segments [Domain] Less: Expenses [Abstract] Expenses Potential damages sought Loss Contingency, Damages Sought, Value Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis] Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Axis] Subscription-Based Contracts Subscription-Based Contracts [Member] Subscription-Based Contracts Losses from foreign sources Income (Loss) from Continuing Operations before Income Taxes, Foreign Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Business combination, provisional information, initial accounting incomplete, adjustment, assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Transaction Costs Effective Income Tax Rate Reconciliation, Nondeductible Expense, Transaction Costs Effective Income Tax Rate Reconciliation, Nondeductible Expense, Transaction Costs Furniture and office equipment Furniture And Office Equipment [Member] Furniture And Office Equipment Statement of Financial Position Location, Balance [Domain] Statement of Financial Position Location, Balance [Domain] Matterport Matterport [Member] Matterport 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outstanding as of December 31, 2024 Common Stock, Value, Issued ROU Assets Finance Lease, Right-of-Use Asset, after Accumulated Amortization Acquisition and integration related costs Acquisition and integration related costs Business Combination, Integration-Related Cost, Expense Business Combination [Axis] Business Combination [Axis] Weighted-average exercise price (in dollars per share) Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price Equity Attributable to NCI Noncontrolling Interest [Member] Thereafter Lessor, Operating Lease, Payment to be Received, after Year Five Building occupied (as a percent) Asset Acquisition, Owner Occupancy Percentage Asset Acquisition, Owner Occupancy Percentage Net deferred tax assets Deferred Tax Assets, Net PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Canceled or expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, 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Liabilities, Net Deferred revenue Increase (Decrease) in Contract with Customer, Liability Litigation accrual Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Litigation Accrual Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Litigation Accrual Long-term debt principal payments Long-Term Debt, Maturity, Interest Payments [Abstract] Long-Term Debt, Maturity, Interest Payments Stock repurchases under stock repurchase programs (in shares) Stock repurchases under stock repurchase programs (in shares) Treasury Stock, Shares, Acquired Thereafter Finance Lease, Liability, to be Paid, after Year Five Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Award Timing Disclosures [Line Items] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Schedule of Inventory Schedule of Inventory, Current [Table Text Block] Remeasurement gain Business Combination, Achieved in Stages, Preacquisition Equity Interest in Acquiree, Remeasurement, Gain Fair value of rollover awards Business Acquisition, Consideration, Replacement Equity Awards, Fair Value Business Acquisition, Consideration, Replacement Equity Awards, Fair Value Accrued expenses Business Combination, Recognized Liability Assumed, Accrued Expenses Business Combination, Recognized Liability Assumed, Accrued Expenses STOCKHOLDERS' EQUITY Equity [Text Block] State Deferred State and Local Income Tax Expense (Benefit) Dividends declared and paid (in AUD per share) Business Combination, Dividend Declared And Paid Per Share Business Combination, Dividend Declared And Paid Per Share Net income Net income Net Income (Loss) Attributable to Parent Consideration for the early termination of the lease Lessor, Lease Buyout Payment Receivable Lessor, Lease Buyout Payment Receivable Arlington, VA Arlington, VA [Member] Arlington, VA Lease liabilities Deferred Tax Assets, Lease Liabilities Deferred Tax Assets, Lease Liabilities Construction in progress Construction in Progress [Member] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Vesting period of options and restricted stock grants (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Other adjustments (percent) Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Preferred stock, shares authorized (in shares) Preferred stock authorized for issuance (in shares) Preferred Stock, Shares Authorized Stock repurchase Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Prepaid expenses Deferred Tax Liabilities, Prepaid Expenses Total contract assets Contract with Customer, Asset, after Allowance for Credit Loss Intangible assets, net Deferred Tax Liabilities, Goodwill and Intangible Assets Term of contract (in years) Lessee, Operating Lease, Term of Contract Customer relationships Customer Relationships [Member] Income (loss) from operations Operating Income (Loss) Retained earnings Retained Earnings (Accumulated Deficit) Non-current portion Deferred Income, Noncurrent Excess tax benefit Effective Income Tax Rate Reconciliation, Excess Tax Benefit, Amount Effective Income Tax Rate Reconciliation, Excess Tax Benefit, Amount Performance Based RSAs Without Market Condition Performance Based RSAs Without Market Condition [Member] Performance Based RSAs Without Market Condition [Member] 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] Residential Real Estate Residential Real Estate Segment [Member] Residential Real Estate Segment 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Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Expiration of the statute of limitation for assessment of taxes Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Variable Rate [Domain] Variable Rate [Domain] Total deferred revenue Beginning balance Ending balance Contract with Customer, Liability Long-term lease liabilities Finance Lease, Liability, Noncurrent Leasing Operations and Other Income, Expense Lessor, Leases [Policy Text Block] All Adjustments to Compensation All Adjustments to Compensation [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Amendment Flag Amendment Flag Tax benefit from stock-based compensation Share-Based Payment Arrangement, Expense, Tax Benefit Shares of common stock authorized for issuance under the plan (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Accrued interest Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss Schedule of Acquired Finite-Lived Intangible Assets by Major Class Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Software development Software development Software Development [Member] Termination Date Trading Arrangement Termination Date Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] 2.800% Senior Notes due July 15, 2030 2.800 Senior Notes [Member] 2.800 Senior Notes Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Foreign currency transaction gain (loss), realized 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by Share-Based Payment Award, Options, Exercisable, Number Exercise Price Range [Domain] Exercise Price Range [Domain] Land and building improvements Land, Buildings and Improvements [Member] Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Litigation accrual Estimated Litigation Liability, Current Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par or stated value per share (in dollars per share) Common Stock, Par or Stated Value Per Share Income taxes receivable Income Taxes Receivable, Current Use of Estimates Use of Estimates, Policy [Policy Text Block] Operating cash flows used in finance leases Finance Lease, Interest Payment on 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Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Acquired Customer Base Acquired customer base Customer Contracts [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member]