Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Long-Term Debt Long-Term Debt, Unclassified [Abstract] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement Statistical Measurement [Domain] Short-term Debt, Type Short-Term Debt, Type [Axis] Title of 12(b) Security Title of 12(b) Security Equity Method Investments Equity Method Investments [Member] Carrying Value Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus Schedule of Warehouse Receivables Schedule Of Warehouse Receivables [Table Text Block] Schedule of warehouse receivables rollforward. Fair value, derivative liability Derivative Liability, Subject to Master Netting Arrangement, Asset Offset Adjustment to Compensation, Amount Adjustment to Compensation Amount Two Cross Currency Swaps Two Currency Swaps [Member] Two Currency Swaps Other non-cash decrease in financing lease right-of-use assets Other Noncash Increases (Decreases) In Finance Lease Right Of Use Assets Other noncash increases (decreases) in finance lease right-of-use assets. Financial Instrument Financial Instrument [Axis] Advisory sales Advisory Sales [Member] Advisory Sales. Segment Reporting [Abstract] Segment Reporting [Abstract] Class A common stock; $0.01 par value; 525,000,000 shares authorized; 289,848,678 and 295,731,478 shares issued and outstanding at June 30, 2026 and December 31, 2025, respectively Common Stock, Value, Issued Tradenames Trademarks [Member] Net change in fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) Leases Lessee, Finance Leases [Text Block] Proceeds from commercial paper, net Proceeds from (Repayments of) Commercial Paper Line of credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Contract assets Contract with Customer, Asset, after Allowance for Credit Loss Derivative Instrument [Axis] Derivative Instrument [Axis] Revision in estimates Accrual for Environmental Loss Contingencies, Revision in Estimates Schedule of Impact of the Outstanding Derivatives in Accumulated Other Comprehensive Loss Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] Revolving credit facility, maturity date January 31, 2024 Revolving Credit Facility, Maturity Date January 31, 2024 [Member] Revolving Credit Facility, Maturity Date January 31, 2024 Schedule of Excess Purchase Price Over Estimated Fair Value of Net Assets Acquired Business Combination, Goodwill, Reportable Segment Assignment [Table Text Block] Amendment Flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Consolidated Entities Consolidated Entities [Axis] Current Liabilities: Liabilities, Current [Abstract] Average price per share (in dollars per share) Shares Acquired, Average Cost Per Share Schedule of Fair Value of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Additional accordion option Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit Gerardo I. Lopez [Member] Gerardo I. Lopez Asset-backed securities Asset-Backed Securities [Member] Property, plant & equipment Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Advisory leasing Advisory Leasing [Member] Advisory Leasing. Depreciation and amortization Other Depreciation and Amortization Net non-cash mortgage servicing rights and premiums on loan sales Gain (Loss) on Disposition of Other Assets Loss Contingencies [Table] Loss Contingencies [Table] Amortization of other assets Amortization Origination of mortgage loans Origination of mortgage loans Payment for Origination, Loan, Mortgage, Held-for-Sale Leases [Abstract] Leases [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Total lease liabilities Operating And Financing Lease Liability Operating and financing lease liability. Consolidated Entities Consolidated Entities [Domain] Currency swaps mature on July 10, 2028 Currency Swaps Mature on July 10, 2028 [Member] Currency Swaps Mature on July 10, 2028 Estimated based on discounted forecasted cash flows Reorganization Value, Present Value of Discounted Cash Flows of Emerging Entity Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Fannie Mae Multifamily ASAP Program, Pricing Warehouse Line Of Credit Four [Member] Warehouse line of credit four. Entity Address, State or Province Entity Address, State or Province Other non-cash increases in operating lease right-of-use assets Other Noncash Increases Decreases In Operating Lease Right Of Use Assets Other noncash increases (decreases) in operating lease right-of-use assets. PEO Total Compensation Amount PEO Total Compensation Amount Foreign currency translation gain (loss) Foreign currency translation (loss) gain Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Class A common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Other intangible assets, net of accumulated amortization of $2,933 and $2,764 at June 30, 2026 and December 31, 2025, respectively Intangible Asset, Excluding Goodwill, after Accumulated Amortization Share Repurchase Program Share Repurchase Program [Domain] Gross notional amount Aggregate notional value Derivative, Notional Amount Weighted average shares outstanding for basic income per share (in shares) Weighted Average Number of Shares Outstanding, Basic Net results related to the wind-down of certain businesses Restructuring Costs Related To The Wind Down Of Certain Businesses Restructuring Costs Related To The Wind Down Of Certain Businesses. Contract assets Contract assets, current Contract with Customer, Asset, after Allowance for Credit Loss, Current Accumulated impairment losses Goodwill, Impaired, Accumulated Impairment Loss Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Number of reportable segments Number of Reportable Segments Investment management Investment Management Property Management Brokerage And Other Professional Services [Member] Investment management property management brokerage and other professional services. Total Current Liabilities Liabilities, Current Funded loans unpaid principal Funded Loan Principal Amount Outstanding Principal amount outstanding as of the balance-sheet date of loans funded as part of a loss sharing arrangement with a third party. Customer relationships Customer Relationships [Member] Short-term Debt, Type Short-Term Debt, Type [Domain] Entity Address, City or Town Entity Address, City or Town Net decrease in mortgage servicing rights included in warehouse receivables Net Increase (Decrease) In Mortgage Servicing Rights Included In Warehouse Receivables Net increase (decrease) in mortgage servicing rights included in warehouse receivables. Gains (losses) recognized in AOCL on cross-currency swaps related to changes included in the assessment of hedge effectiveness Derivative, Fair Value Hedge, Included in Effectiveness, Gain (Loss) Investments in unconsolidated subsidiaries Equity Method Investments, Fair Value Disclosure Class of Financing Receivable Class of Financing Receivable [Domain] Commercial paper program Commercial Paper Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Charges related to indirect tax audits and settlements Charges Related To Indirect Tax Settlement Charges Related To Indirect Tax Settlement Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Level 2 Fair Value, Inputs, Level 2 [Member] Other intangible assets, accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Maximum Facility Size Amounts available to borrow under credit agreement Line of Credit Facility, Maximum Borrowing Capacity Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Current maturities of long-term debt Less: current maturities of long-term debt Long-Term Debt, Current Maturities Real estate under development Real Estate Held for Development and Sale Development services Real Estate Development Services [Member] Real estate development services. Provision associated with Telford’s fire safety remediation efforts Environmental Remediation Expense, before Recovery United States UNITED STATES Sale of mortgage loans Proceeds from sale of mortgage loans Proceeds from Sale, Loan, Mortgage, Held-for-Sale Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Percentage of face value Debt Instrument, Principal Amount Issued, Percentage Of Face Value Debt Instrument, Principal Amount Issued, Percentage Of Face Value Recently Adopted Accounting Pronouncements Pending Adoption New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Summarized Financial Information by Segment Segment Reporting [Table Text Block] Non- controlling interests Noncontrolling Interest [Member] Use of Estimates Use of Estimates, Policy [Policy Text Block] Unsecured Debt Unsecured Debt [Member] Schedule of Reconciliation for Liabilities Measured at Fair Value Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Repayment of revolving credit facility Repayments of Lines of Credit Intangible assets Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Short-Term Borrowings Short-Term Debt [Abstract] Other current assets Variable Interest Entity Entity Maximum Loss Exposure Amount Other Current Assets Variable interest entity entity maximum loss exposure amount other current assets. Commitments to investment in future real estate investment Commitments To Investment In Future Real Estate Investment The reporting entity's aggregate commitments to fund future co-investments with its clients in certain real estate investments. Facilities management Facilities Management [Member] Facilities Management Current liabilities Business Combination, Recognized Liability Assumed, Liability, Current Document Period End Date Document Period End Date Changes in: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] 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] Unrecognized tax benefits Unrecognized Tax Benefits Aggregate principal amount Debt Instrument, Face Amount Basic income per share: Basic Income Per Share Earnings Per Share, Basic [Abstract] Contingent Consideration Contingent Consideration [Member] Contingent Consideration Costs and expenses: Costs and Expenses [Abstract] Security Exchange Name Security Exchange Name Debt agreement term Debt Instrument, Term Sale of mortgage loans Sale Of Mortgage Loans Held For Sale Sale of mortgage loans held for sale. Equity Method Investment, Nonconsolidated Investee Equity Method Investment, Nonconsolidated Investee [Axis] Warehouse receivables Financing Receivable, before Allowance for Credit Loss Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Accounts payable, accrued expenses and long-term deferred and contingent consideration Accounts Payable, Accrued Expenses and Long-term Deferred and Contingent Consideration [Member] Accounts Payable, Accrued Expenses and Long-term Deferred and Contingent Consideration Estimated fair value of investment Equity Method Investment, Other-than-Temporary Impairment Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Interest income Derivative Instrument Gain Loss Reclassified From AOCI To Interest Expense Net Of Interest Income Derivative Instrument Gain Loss Reclassified From AOCI To Interest Expense Net Of Interest Income Operating lease liabilities Operating Operating Lease, Liability, Current Secured Overnight Financing Rate (SOFR) Adjustment Secured Overnight Financing Rate (SOFR) Adjustment [Member] Secured Overnight Financing Rate (SOFR) Adjustment 2023 Credit Agreement 2023 Credit Agreement [Member] 2023 Credit Agreement Finance Finance Lease, Right-of-Use Asset, after Accumulated Amortization Mortgages Mortgages [Member] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Name Outstanding Recovery, Individual Name Right-of-use and other assets Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Right of Use And Other Assets Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Right of Use And Other Assets. Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Proceeds from sale of mortgage loans: Proceeds from Collection, Loan, Held-for-Sale [Abstract] Increase compared to prior year Accrual for Environmental Loss Contingencies, Period Increase (Decrease) Total liabilities Liabilities Trading Symbol Trading Symbol Discount Rate Measurement Input, Discount Rate [Member] Geographical Geographical [Domain] 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] Income taxes payable Accrued Income Taxes, Current Schedule of Aggregate Estimated Fair Values of Assets Acquired and Liabilities Assumed Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Company Selected Measure Name Company Selected Measure Name 2027 Credit agreement Revolving Credit Facility, Maturity Date March 31, 2027 [Member] Revolving Credit Facility, Maturity Date March 31, 2027 Industrious Industrious National Management Company LLC [Member] Industrious National Management Company LLC Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Business Combination, Contingent Consideration, Type [Axis] Business Combination, Contingent Consideration, Type [Axis] Investments in unconsolidated subsidiaries Variable Interest Entity Entity Maximum Loss Exposure Amount Investments In Affiliates Subsidiaries Associates And Joint Ventures Variable interest entity entity maximum loss exposure amount investments in affiliates subsidiaries associates and joint ventures. Non-cash investing and financing activities: Noncash Investing and Financing Items [Abstract] Diluted income per share: Diluted Income Per Share Earnings Per Share, Diluted [Abstract] Unamortized debt issuance costs Total long-term debt Long-Term Debt, Gross Capital investments Equity Securities, FV-NI, Cost Credit Facility Credit Facility [Domain] Asset Class [Domain] Asset Class [Domain] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Noncompete Agreements Noncompete Agreements [Member] Other Business Combination, Consideration Transferred, Tangible and Intangible Assets, Excluding Cash CASH FLOWS FROM OPERATING ACTIVITIES: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Equity interest percentage Business Combination, Voting Equity Interest Acquired, Percentage Weighted average shares outstanding for diluted income per share (in shares) Weighted average shares outstanding for diluted income per share (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] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Other, net of tax Other Comprehensive Income, Other, Net of Tax Deferred income taxes Deferred Income Taxes and Tax Credits Commercial paper Commercial Paper [Member] Derivatives and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] U.S. treasury securities US Treasury Securities [Member] Business and finance transformation Business and finance transformation Business and finance transformation Building Operations & Experience Building Operations & Experience Building Operations & Experience [Member] Building Operations & Experience Liabilities Lease Liabilities [Abstract] Lease liabilities. Goodwill deductible amount Business Combination, Goodwill, Expected Tax Deductible, Amount Total short-term borrowings Short-Term Debt Maximum exposure to loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Telford fire safety remediation Telford Fire Safety Remediation [Member] Telford Fire Safety Remediation Project Management Project Management Segment [Member] Project Management Segment Maximum leverage ratio of total debt less available cash to EBITDA expressed in percentage Maximum Leverage Ratio Of Debt To Earnings Before Interest Tax Depreciation And Amortization Expressed In Percentage This element represents the maximum ratio of debt less available cash to earnings before interest, taxes, depreciation and amortization (EBITDA) allowed in the reporting entity's credit agreement. Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Schedule of Reconciliation for Assets Measured at Fair Value Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Goodwill Goodwill [Text Block] Award Timing Predetermined Award Timing Predetermined [Flag] Intangible Asset, Goodwill and Other [Abstract] Letters of credit outstanding amount Letters of credit outstanding Letters of Credit Outstanding, Amount Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Compensation expense for equity awards APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Loan servicing Loan Servicing [Member] Loan servicing. Level 1 Fair Value, Inputs, Level 1 [Member] Advisory Services Advisory Services Advisory Services Segment [Member] Advisory Services Segment Effective tax rate Effective Income Tax Rate Reconciliation, Percent Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Total costs and expenses Cost And Expenses Excluding Gain On Disposition Of Real Estate Assets Cost and expenses excluding gain on disposition of real estate assets. Total leased assets Operating And Finance Lease Right Of Use Asset Operating and finance lease right of use asset. Warehouse receivables Beginning balance Ending balance Warehouse receivables Loan Receivable Mortgage Warehouse Lending Current Reflects the gross carrying amount of unpaid loans pertaining to a revolving line of credit used by mortgage bankers in which the mortgage banker originates and purchases mortgage loans due within one year or the normal operating cycle, if longer. All Executive Categories All Executive Categories [Member] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Repurchase of common stock Repurchase of common stock Stock Repurchased and Retired During Period, Value Class of Financing Receivable Class of Financing Receivable [Axis] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Funded loan subject to loss sharing arrangements Funded Loan Subject To Loss Sharing Arrangements [Member] Funded loan subject to loss sharing arrangements. Redeemable non-controlling interests in consolidated entities Redeemable Noncontrolling Interest, Equity, Carrying Amount Antidilutive Securities Antidilutive Securities [Axis] Alternative investment, measurement input percentage Alternative Investment, Measurement Input Operating lease assets Operating Operating Lease, Right-of-Use Asset SBL program Multifamily Small Balance Loan Program [Member] Multifamily small balance loan program. US Treasury (UST) Interest Rate US Treasury (UST) Interest Rate [Member] Scotia Bank Scotia Bank [Member] Scotia Bank Income taxes, net Increase (Decrease) in Income Taxes Receivable Derivative Liability, Statement of Financial Position [Extensible Enumeration] Derivative Liability, Statement of Financial Position [Extensible Enumeration] Schedule of Calculations of Basic and Diluted Income Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] 5.250% senior notes due 2036 Senior Notes, Five Point Two Five Zero Percent [Member] Senior Notes, Five Point Two Five Zero Percent Estimated Fair Value of Net Assets Acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name Debt Instrument, Name [Domain] Segments Segment Reporting [Text Block] Minimum Minimum [Member] Scotia Bank, Pricing Scotia Bank, Pricing [Member] Scotia Bank, Pricing Expiration Date Trading Arrangement Expiration Date Costs associated with efficiency and cost-reduction initiatives Restructuring Costs, Efficiency and Cost-Reduction Restructuring Costs, Efficiency and Cost-Reduction Hedging Relationship [Axis] Hedging Relationship [Axis] Schedule of Disaggregation of Revenue from Contracts with Customers Disaggregation of Revenue [Table Text Block] Variable Interest Entities (VIEs) Variable Interest Entity Disclosure [Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Total Equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest 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] Total liabilities at fair value Financial Liabilities Fair Value Disclosure Deferred consideration, discount Business Combination, Consideration Transferred, Liabilities Incurred, Discount Business Combination, Consideration Transferred, Liabilities Incurred, Discount Loss contingency, estimate of possible loss Loss Contingency, Estimate of Possible Loss Deferred and contingent consideration Deferred and contingent consideration Business Combination, Consideration Transferred, Liabilities Incurred Business Combination [Line Items] Business Combination [Line Items] Foreign currency translation gain Temporary Equity, Foreign Currency Translation Loss Gain Temporary Equity, Foreign Currency Translation Loss Gain Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Pass-through costs Revenue From Contract With Customer, Pass-Through Costs Recognized As Income Revenue From Contract With Customer, Pass-Through Costs Recognized As Income Other short-term borrowings Commercial Paper and Other Short-Term Borrowings Commercial Paper and Other Short-Term Borrowings Class A common stock, shares authorized (in shares) Common Stock, Shares Authorized Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Number of housing units Number of Units in Real Estate Property Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Exercise Price Award Exercise Price Schedule of Restructuring and Related Costs [Table] Restructuring Cost [Table] CASH FLOWS FROM INVESTING ACTIVITIES: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Segment Reporting [Line Items] Segment Reporting [Line Items] Authorized share repurchase amount Share Repurchase Program, Authorized, Amount Less: Estimated fair value of net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill, Less Noncontrolling Interest Document Quarterly Report Document Quarterly Report 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 Segments [Domain] Warehouse lines of credit (which fund loans that U.S. Government Sponsored Enterprises have committed to purchase) Carrying Value Warehouse lines of credit Warehouse Agreement Borrowings Lender Name Lender Name [Axis] Effect of currency exchange rate changes on cash and cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Long-Term Debt and Short-Term Borrowings Debt Disclosure [Text Block] Indirect tax liabilities primarily related to sales and use tax Commitments and Contingencies, Indirect Tax Liability Commitments and Contingencies, Indirect Tax Liability Non-current contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Critical infrastructure Critical Infrastructure [Member] Critical Infrastructure Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Investments in unconsolidated subsidiaries (with $425 and $421 at fair value at June 30, 2026 and December 31, 2025, respectively) Total investment in unconsolidated subsidiaries Equity Method Investments Business Combination [Table] Business Combination [Table] Equity Component Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Net change in fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Measurement Input Type [Domain] Measurement Input Type [Domain] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Performance guarantee Performance Guarantee [Member] Global Workplace Solutions Global Workplace Solutions Segment [Member] Global Workplace Solutions Segment Adoption Date Trading Arrangement Adoption Date Interest rate Debt Instrument, Interest Rate, Stated Percentage Total CBRE Group, Inc. Stockholders’ Equity Equity, Attributable to Parent Assets Lessee Assets [Abstract] Lessee assets. Write-off of financing costs on extinguished debt Deferred Debt Issuance Cost, Writeoff Restructuring Type [Axis] Restructuring Type [Axis] Equity securities Equity Securities, FV-NI, Current Telford Fire Safety Remediation Environmental Loss Contingency Disclosure [Text Block] 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 Losses were offset by foreign currency transaction gains on hedged loans Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Warehouse Receivables & Warehouse Lines of Credit Warehouse Receivables And Warehouse Lines Of Credit [Text Block] Warehouse receivables and warehouse lines of credit. Insider Trading Policies and Procedures [Line Items] Acquisitions Goodwill, Measurement Period Adjustment Non-current: Lease Liabilities Noncurrent [Abstract] Lease liabilities noncurrent. Other financing activities, net Proceeds from (Payment for) Other Financing Activity Receivables, less allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss, Current Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Schedule of Warehouse Lines of Credit in Place Schedule of Line of Credit Facilities [Table Text Block] Contingent Consideration Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Other Other Senior Notes [Member] Other Senior Notes TD Bank T D Bank [Member] TD bank. Type of Restructuring [Domain] Type of Restructuring [Domain] Business Combination Business Combination [Domain] Interest expense, net of interest income Interest Income (Expense), Nonoperating Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Number ​of ​operating​ segments Number of Operating Segments Shares excluded in computation of diluted income per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Changes in Goodwill by Segment Goodwill [Table Text Block] Goodwill, gross, beginning balance Goodwill, gross, ending balance Goodwill, Gross Entity Central Index Key Entity Central Index Key Property and equipment, accumulated depreciation and amortization Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Additional paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Corporate, other and eliminations Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Warehouse agreement borrowings Warehouse Agreement Borrowings [Member] Business Combination Business Combination [Axis] 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 used in operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Other Stockholders' Equity, Other Warehouse Receivables And Warehouse Lines Of Credit [Line Items] Warehouse Receivables And Warehouse Lines Of Credit [Line Items] Warehouse receivables and warehouse lines of credit. Income Statement [Abstract] Income Statement [Abstract] CBRE Group, Inc. Stockholders’ Equity: Equity, Attributable to Parent [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Axis] Investment, Name [Axis] Investment, Name [Axis] Compensation and employee benefits payable Other Employee-related Liabilities, Current Designated as hedging instrument Designated as Hedging Instrument [Member] Deferred tax assets, net Deferred Income Tax Assets, Net Finance Finance Lease, Liability, Noncurrent Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] JP Morgan (Bridge Loans) Warehouse Line Of Credit Three [Member] Warehouse Line Of Credit Three Corporate, other and eliminations Intersegment Eliminations [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of Supplemental Balance Sheet Information Related to Leases Schedule Of Supplemental Balance Sheet Information Related To Leases [Table Text Block] Schedule Of Supplemental Balance Sheet Information Related To Leases Percentage of maximum original principal amount loan loss Percentage Of Maximum Original Principal Amount Loan Loss Maximum original principal amount loan loss percentage. Variable rate (as a percent) Debt Instrument, Basis Spread on Variable Rate City Area Code City Area Code Variable Rate [Domain] Variable Rate [Domain] Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] 5.950% senior notes due 2034 Senior Notes, Five Point Nine Five Percent [Member] Senior Notes, Five Point Nine Five Percent All Individuals All Individuals [Member] Schedule of Geographic Information Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Name Forgone Recovery, Individual Name Investment in Unconsolidated Subsidiaries Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Volatility Measurement Input, Option Volatility [Member] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Commitments to investment in future real estate investment (as a percent) Real Estate Investments, Maximum Equity In Real Estate Investment, Percent Real Estate Investments, Maximum Equity In Real Estate Investment, Percent Commercial mortgage origination Commercial Mortgage Origination [Member] Commercial mortgage origination. Fair value of existing equity method investment in Industrious Business Combination, Consideration Transferred, Equity Interest Statement [Line Items] Statement [Line Items] Total assets Assets Secured overnight financing rate (SOFR) overnight index swap Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Chad J. Doellinger, Rule Trading Arrangement, Common Stock Vesting [Member] Chad J. Doellinger, Rule Trading Arrangement, Common Stock Vesting Entity [Domain] Entity [Domain] Estimated environmental liability Accrual for Environmental Loss Contingencies Variable interest entity, not primary beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Equity Method Investment, Nonconsolidated Investee Equity Method Investment, Nonconsolidated Investee [Domain] Contingent Earnout Payment Contingent Earnout Payment [Member] Contingent Earnout Payment Operating segments Operating Segments [Member] Fannie Mae ASAP Program Fannie Mae A S A P Program [Member] Fannie Mae ASAP program. Commitment to investment in consolidated projects Other Commitment, Capital Investment In Consolidated Projects Other Commitment, Capital Investment In Consolidated Projects JP Morgan J P Morgan [Member] JP Morgan. Total liabilities assumed Business Combination, Recognized Liability Assumed, Liability Total gains (losses) recognized in AOCL on cross-currency swaps Other Comprehensive Income (Loss), before Reclassifications, before Tax Operating lease and other liabilities Business Combination, Recognized Liability Assumed, Lease Obligation Accounts payable and accrued expenses Accounts Payable and Other Accrued Liabilities, Current PEO PEO [Member] Amortization related of MSRs Net non-cash mortgage servicing rights Amortization of Mortgage Servicing Rights (MSRs) Income Per Share and Stockholders’ Equity Earnings Per Share And Stockholders Equity [Text Block] Earnings per share and stockholder's equity. Warehouse receivable Warehouse Receivable [Member] Warehouse receivable. Repurchase of common stock (in shares) Stock Repurchased and Retired During Period, Shares Euro Term Loan Facility Euro Term Loan Facility [Member] Euro term loan facility. Fair value, derivative asset Derivative Asset, Subject to Master Netting Arrangement, Liability Offset Measurement Basis Measurement Basis [Axis] Other liabilities Other Liabilities, Noncurrent Investment in Unconsolidated Subsidiaries Investment in Unconsolidated Subsidiaries [Member] Investment in Unconsolidated Subsidiaries Goodwill Excess purchase price over estimated fair value of net assets acquired Goodwill All other countries All Other Countries [Member] All Other Countries [Member] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] 5.500% senior notes due 2029 Senior Notes, Five Point Five Percent [Member] Senior Notes, Five Point Five Percent Recognized revenue included in contract liability Recognized revenue included in contract liability Contract with Customer, Liability, Revenue Recognized Net gains recognized in income (amount excluded from effectiveness testing): Gain Loss Reclassified From AOCI To [Abstract] Gain Loss Reclassified From AOCI To [Abstract] Commitments to investment in unconsolidated real estate subsidiary Other Commitment, Capital Investment In Unconsolidated Entity Other Commitment, Capital Investment In Unconsolidated Entity Forgiveness of note receivable Business Combination Forgiveness of Note Receivable Business Combination Forgiveness of Note Receivable Accumulated earnings Retained Earnings [Member] Non-current operating lease liabilities Operating Operating Lease, Liability, Noncurrent Operating expenses and allocations Operating Expenses Revolving credit facility Revolving Credit Facility [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Class A common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Corporate debt securities Corporate Debt Securities [Member] Net income per share attributable to CBRE Group, Inc. (in dollars per share) Diluted income per share attributable to CBRE Group, Inc. stockholders (in dollars per share) Earnings Per Share, Diluted Other Other Equity Method Investments [Member] Other Equity Method Investments Entity Current Reporting Status Entity Current Reporting Status Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Monte Carlo Pricing Model Valuation Technique, Monte Carlo Pricing Model [Member] Total Shareholder Return Amount Total Shareholder Return Amount Units repurchased for payment of taxes on equity awards Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Project management Project Management [Member] Project Management Real Estate Investment Real Estate Investment [Member] Accrued compensation expenses Increase (Decrease) in Employee Related Liabilities Schedule of Business Combination Business Combination [Table Text Block] Schedule of Supplemental Cash Flow Information and Non-Cash Activity Related to Operating Leases Schedule Of Supplemental Cash Flow Information And Non Cash Activity Related To Operating Leases [Table Text Block] Schedule Of Supplemental Cash Flow Information And Non Cash Activity Related To Operating Leases Reconciliation of net income to net cash used in operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Total assets acquired Business Combination, Recognized Asset Acquired, Asset Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Topic 606 Revenue Revenue from Contract with Customer, Excluding Assessed Tax Reclassification from AOCL Reclassification from AOCI, Current Period, Tax CASH FLOWS FROM FINANCING ACTIVITIES: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property and equipment, net of accumulated depreciation and amortization of $2,280 and $2,137 at June 30, 2026 and December 31, 2025, respectively Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Revolving credit facilities Line of Credit, Current Capital contributions related to investments Payments to Acquire Interest in Joint Venture Financial Instruments Financial Instruments [Domain] Schedule of Condensed Financial Information of Equity Method Investments Equity Method Investments [Table Text Block] Derivative assets Derivative Asset 4.900% senior notes due 2033 Senior Notes, Four Point Nine Zero Percent [Member] Senior Notes, Four Point Nine Zero Percent Intangible Asset, Finite-Lived, Class Intangible Asset, Finite-Lived, Class [Axis] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Less: Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest 2019 Credit agreement Two Thousand Nineteen Credit Agreement [Member] Two thousand Nineteen credit agreement. Estimated Fair Value Estimate of Fair Value Measurement [Member] Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Prepaid expenses Prepaid Expense, Current Sales / Payments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other investing activities, net Payment for (Proceeds from) Other Investing Activity Turner & Townsend Turner & Townsend Partners [Member] Turner & Townsend Partners Segment Reporting [Table] Segment Reporting [Table] 5.500% senior notes due 2035 Senior Notes, Five Point Five Zero Percent [Member] Senior Notes, Five Point Five Zero Percent Warehouse lines of credit Increase Decrease In Warehouse Lines Of Credit Increase (decrease) in warehouse lines of credit. Integration and other costs related to acquisitions Other Nonrecurring (Income) Expense Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Contingent consideration, current Business Combination, Contingent Consideration, Liability, Current Acquisition and development of real estate assets Payments to Acquire and Develop Real Estate Other current assets Other Assets, Current Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating income Operating income Operating Income (Loss) Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Environmental Remediation Expense, before Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] Current Fiscal Year End Date Current Fiscal Year End Date Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Other portfolio services Other Portfolio Services [Member] Other Portfolio Services Acquisitions Business Combination [Text Block] 2023 Credit Agreement, Tranche A Euro Denominated Term Loan 2023 Credit Agreement, Tranche A Euro Denominated Term Loan [Member] 2023 Credit Agreement, Tranche A Euro Denominated Term Loan Cash paid during the period for: Cash Paid During Period For [Abstract] Cash paid during period for. 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] Chad J. Doellinger [Member] Chad J. Doellinger Warehouse Receivables And Warehouse Lines Of Credit [Table] Warehouse Receivables And Warehouse Lines Of Credit [Table] Warehouse receivables and warehouse lines of credit. Distributions to non-controlling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Asset impairments Asset, Impairment Loss Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Class A common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Investments in Unconsolidated Subsidiaries Equity Method Investments and Joint Ventures Disclosure [Text Block] Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Schedule of Maximum Exposure to Loss Schedule of Variable Interest Entities [Table Text Block] Investments at fair value using NAV Investments, Unconsolidated Subsidiaries, Fair Value Investments, Unconsolidated Subsidiaries, Fair Value Outstanding balance of loans Loans Payable Current assets Business Combination, Recognized Asset Acquired, Asset, Current Gains (losses) recognized in AOCL on cross-currency swaps related to changes excluded from the assessment of hedge effectiveness Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net Equity Components Equity Components [Axis] Dilutive effect of contingently issuable shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares Product and Service Product and Service [Domain] Income tax payments, net Income Tax Paid, after Refund Received Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity Interactive Data Current Entity Interactive Data Current Finance Finance Lease, Liability, Current Variable Rate [Axis] Variable Rate [Axis] Less: Net income attributable to non-controlling interests Net income attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Assets available for recourse Assets Available For Recourse Assets available for recourse under the Fannie Mae DUS lender program. Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Deferred tax liabilities, net Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Gain on disposition of real estate Gain on sale of real estate assets Gain on disposition of real estate Gains (Losses) on Sales of Investment Real Estate U.S. Dollar Term Loan U.S. Dollar Term Loan [Member] U.S. Dollar Term Loan Entity Small Business Entity Small Business Comprehensive income attributable to CBRE Group, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Less: unamortized discount Debt Instrument, Unamortized Discount Termination Date Trading Arrangement Termination Date Mezzanine Equity: Redeemable Noncontrolling Interest, Equity, Carrying Amount [Abstract] Amortization Period Intangible Asset, Finite-Lived, Acquired, Weighted-Average Amortization Period Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Co-investment commitments Variable Interest Entity Entity Maximum Loss Exposure Amount Commitments To Investment In Future Real Estate Investment Variable interest entity entity maximum loss exposure amount commitments to investment in future real estate investment. Increase (decrease) in income taxes Increase (Decrease) in Income Taxes Finite lived intangible assets, amount assigned at acquisition date 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] Interest expense, net of interest income Interest Income (Expense), Operating MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other current liabilities Other Liabilities, Current Non-current tax liabilities Liability for Uncertainty in Income Taxes, Noncurrent Other assets Other Assets, Noncurrent Line of Credit Facility, Lender Line of Credit Facility, Lender [Domain] Document Type Document Type 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] Settlement of long-term debt Gain (Loss) on Extinguishment of Debt Fair Value as of Grant Date Award Grant Date Fair Value Redemption price percentage Debt Instrument, Redemption Price, Percentage Schedule of Goodwill [Table] Goodwill [Table] Deferred and/or contingent consideration Deferred Purchase Consideration Deferred Purchase Consideration Redeemable Non-controlling interests Increase (Decrease) in Temporary Equity [Roll Forward] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Capacity remaining under current stock repurchase programs Share Repurchase Program, Remaining Authorized, Amount Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Reallocation Goodwill Reallocation Goodwill Reallocation Pearce Services, LLC Pearce Services, LLC [Member] Pearce Services, LLC Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Net Investment Hedge Net Investment Hedging [Member] Income before provision for 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] Revenue Total Revenue Revenues Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Antidilutive Securities, Name Antidilutive Securities, Name [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Equity income (loss) from unconsolidated subsidiaries Equity loss from investments Equity (loss) income from unconsolidated subsidiaries Equity income (loss) from unconsolidated subsidiaries Income (Loss) from Equity Method Investments Accounts payable, accrued liabilities and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Property management Property Management [Member] Property Management Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Impact of fair value non-cash adjustments related to unconsolidated equity investments Impact Of Fair Value Adjustments Related to Unconsolidated Equity Impact Of Fair Value Adjustments Related to Unconsolidated Equity Executive Category: Executive Category [Axis] Goodwill [Roll Forward] Goodwill [Roll Forward] LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Corporate, other and eliminations Corporate And Reconciling Items [Member] Corporate And Reconciling Items Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Schedule of Fair Value of Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Fair Value Measurements Fair Value Disclosures [Text Block] Acquisition of non-controlling interests Temporary Equity, Acquisition of Non Controlling Interests Temporary Equity, Acquisition of Non Controlling Interests Level 3 Fair Value, Inputs, Level 3 [Member] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] PEO Name PEO Name Geographical Geographical [Axis] Contract liabilities Contract with Customer, Liability Other Other Short-Term Borrowings Fair Value Measured at Net Asset Value Fair Value Measured at Net Asset Value Per Share [Member] Schedule of Short-term Debt [Table] Short-Term Debt [Table] Other segment adjustments Segment Reporting, Other Segment Item, Amount Repayment of long-term debt Repayments of Secured Debt Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Legal Entity [Axis] Legal Entity [Axis] Assets Acquired: Business Combination, Recognized Asset Acquired, Asset [Abstract] CASH, CASH EQUIVALENTS AND RESTRICTED CASH, AT BEGINNING OF PERIOD CASH, CASH EQUIVALENTS AND RESTRICTED CASH, AT END OF PERIOD Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cost of revenue, excluding pass-through costs Cost Of Revenue Excluding Pass Through Costs Cost Of Revenue Excluding Pass Through Costs New 364-Day Revolving credit agreement Revolving Credit Facility, Maturity Date June 22, 2027 [Member] Revolving Credit Facility, Maturity Date June 22, 2027 Indefinite lived intangible assets, amount assigned at acquisition date Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Indefinite-Lived 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] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Restricted cash 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] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument Debt Instrument [Axis] Cash consideration Payments to Acquire Businesses, Gross Equity method investments in unconsolidated subsidiaries, variations in ownership percentage Equity Method Investment, Ownership Percentage Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Schedule of Long-Term Debt Schedule of Debt [Table Text Block] Investment, Name [Domain] Investment, Name [Domain] Leases Lessee, Operating Leases [Text Block] Long-term Debt, Type Long-Term Debt, Type [Domain] Net income per share attributable to CBRE Group, Inc. (in dollars per share) Basic income per share attributable to CBRE Group, Inc. stockholders (in dollars per share) Earnings Per Share, Basic Measurement Input Type [Axis] Measurement Input Type [Axis] Repurchase of common stock Payments for Repurchase of Common Stock Contract liabilities Contract with Customer, Liability, Current Total Current Assets Assets, Current Statistical Measurement Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Gains (premiums on loan sales) Gain (Loss) on Sales of Mortgage-Backed Securities (MBS) Long-term debt, net of current maturities Long-Term Debt, Excluding Current Maturities Funded loan not subject to loss sharing arrangements Funded Loan Not Subject To Loss Sharing Arrangements [Member] Funded loan not subject to loss sharing arrangements. Cost of revenue Cost of Revenue Award Type Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Receivables, less allowance for doubtful accounts of $136 and $125 at June 30, 2026 and December 31, 2025, respectively Accounts Receivable, after Allowance for Credit Loss, Current Accumulated earnings Retained Earnings (Accumulated Deficit) Stock repurchase program additional authorized amount Stock Repurchase Program Additional Authorized Amount Stock repurchase program additional authorized amount. Restructuring and Related Activities [Abstract] Restructuring and Related Activities [Abstract] Product and Service Product and Service [Axis] 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] Operating income Equity Method Investment Summarized Financial Information Operating Profit Loss This item represents the disclosure of summarized financial information for unconsolidated subsidiaries and 50 percent-or-less owned entities accounted for using the equity method of accounting. If investments in common stock of corporate joint ventures or other investments accounted for under the equity method are, in the aggregate, material in relation to the financial position or results of operations of an investor, it may be necessary to present summarized information as to assets of the investee, or group of investments for which combined disclosure is appropriate, either by individual financial statement caption or in groups, as appropriate. Such summarized financial information may, at a minimum, include operating profit/loss. Beginning balance Ending balance Temporary Equity, Including Noncontrolling Interest Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Warehouse Receivables And Warehouse Lines Of Credit [Line Items] Short-Term Debt [Line Items] Class A common stock Common Stock [Member] Proceeds from long-term debt Proceeds from Issuance of Secured Debt Available for sale debt securities Debt Securities, Available-for-Sale Fair Value Measurement Fair Value Measurement [Domain] Contingent consideration Business Combination, Contingent Consideration, Liability Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Revolving credit agreements Revolving Credit Facility, Maturity Date June 24, 2030 [Member] Revolving Credit Facility, Maturity Date June 24, 2030 Cover [Abstract] Cover [Abstract] United Kingdom UNITED KINGDOM Equity method investment, nonconsolidated investee or group of investees Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Derivative Contract [Domain] Derivative Contract [Domain] Units repurchased for payment of taxes on equity awards APIC, Share-Based Payment Arrangement, Recognition and Exercise Foreign exchange movement Goodwill, Foreign Currency Translation, Gain (Loss) Equity Awards Adjustments Equity Awards Adjustments [Member] Operating, administrative and other Operating Administrative And Other Expenses Operating, administrative and other expenses. Hedging Relationship [Domain] Hedging Relationship [Domain] Total Liabilities and Equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Chad J. Doellinger, Rule Trading Arrangement, Common Stock [Member] Chad J. Doellinger, Rule Trading Arrangement, Common Stock Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Non-controlling interests Equity, Attributable to Noncontrolling Interest Segments Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Tabular List, Table Tabular List [Table Text Block] JP Morgan (Business Lending Activity) Warehouse Line Of Credit Two [Member] Warehouse line of credit two. Other income Other income (loss) Other Nonoperating Income (Expense) Non-current income taxes receivable Income Taxes Receivable, Noncurrent Outstanding balance of loans, current Loans Payable, Current Income taxes receivable Income Taxes Receivable, Current Name Awards Close in Time to MNPI Disclosures, Individual Name 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] BofA, pricing Warehouse Line Of Credit Seven [Member] Warehouse line of credit seven. Acquisition of non-controlling interests Noncontrolling Interest, Increase (Decrease) From Business Combination Noncontrolling Interest, Increase (Decrease) From Business Combination Real Estate Investments Real Estate Investments Real Estate Investments Segment [Member] Real Estate Investments Segment Business Combination, Contingent Consideration, Type [Domain] Business Combination, Contingent Consideration, Type [Domain] Swingline loans Swingline Loans [Member] Swingline Loans JP Morgan Chase Bank, N.A. (JP Morgan), Pricing Warehouse Line Of Credit One [Member] Warehouse line of credit one. Cash collections of premiums on loan sales Proceeds from Collection, Loan, Mortgage, Held-for-Sale Accrued bonus and profit sharing Accrued Bonuses, Current Adjustment to Compensation: Adjustment to Compensation [Axis] Schedule of Trademarks Acquired as Part of Business Combination Business Combination, Intangible Asset, Acquired, Finite-Lived [Table Text Block] Net income Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Share Repurchase Program Share Repurchase Program [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Bank of America (BofA) Bank Of America [Member] Bank of America. 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 Derivative instruments designated as net investment hedges: Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Investments in unconsolidated subsidiaries, fair value Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Planned Sale, Investments Not Identified, Value Interest Interest Paid, Excluding Capitalized Interest, Operating Activity Capital expenditures Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Carried interest incentive compensation (reversal) expense to align with the timing of associated revenue Carried Interest Incentive Compensation Expense Reversal Carried interest incentive compensation expense (reversal). Sales / Payments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales Hedging Designation [Axis] Hedging Designation [Axis] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Excluding Redeemable Noncontrolling Interest Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Excluding Redeemable Noncontrolling Interest Other adjustments to segment operating profit (loss): Adjustments to increase (decrease) net income: Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Abstract] Maximum leverage ratio during first four quarter that qualified acquisition is consummated Maximum Leverage Ratio During First Four Quarter That Qualified Acquisition Is Consummated Maximum leverage ratio during first four quarter that qualified acquisition is consummated. Credit Facility Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total assets at fair value Assets, Fair Value Disclosure Turner & Townsend Turner & Townsend Holdings Limited [Member] Turner & Townsend Holdings Limited 2.500% senior notes due 2031 Senior Notes, Two Point Five Percent [Member] Senior Notes, Two Point Five Percent Lines of credit principal outstanding Short-Term Debt, Maximum Amount Outstanding During Period Name Measure Name Warehouse Receivables And Warehouse Lines Of Credit [Abstract] Warehouse Receivables And Warehouse Lines Of Credit [Abstract] Warehouse receivables and warehouse lines of credit. Income Taxes Income Tax Disclosure [Text Block] Pay vs Performance Disclosure [Line Items] Guarantees total Guarantor Obligations Maximum Exposure Undiscounted Maximum potential amount of future payments (undiscounted) the reporting entity could be required to make excluding (1) those for which the reporting entity has an outstanding liability already accrued on its consolidated statement of financial position and (2) completion and budget guarantees relating to the reporting entity's Development Services segment. Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Domain] Other non-cash adjustments Other Noncash Income (Expense) Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Total consideration Purchase price Business Combination, Consideration Transferred Additional paid-in capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Payments for business acquired, net of cash acquired Payments to Acquire Business Two, Net of Cash Acquired Non-Marketable Equity Investments Non-Marketable Equity Investments [Member] Non-Marketable Equity Investments November 2024 repurchase program November 2024 Repurchase Program [Member] November 2024 Repurchase Program Europe Interbank Offered Rate (EURIBOR) Europe Interbank Offered Rate (EURIBOR) [Member] Europe Interbank Offered Rate (EURIBOR) Total Out of Scope of Topic 606 Revenue Revenue Not from Contract with Customer Name Trading Arrangement, Individual Name Cross currency swaps Currency Swap [Member] Cash and cash equivalents Cash and Cash Equivalent Basis of Presentation Basis of Accounting [Text Block] Company Selected Measure Amount Company Selected Measure Amount Schedule of Reconciliation of Segment Operating Profit to Net Income Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block] Senior Secured Term Loans Senior Secured Term Loan, Duel 2028 [Member] Senior Secured Term Loan, Duel 2028 Ownership percentage Ownership Percentage [Member] Ownership Percentage Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] 2023 Credit Agreement, Tranche A, US Dollar Denominated Term Loan 2023 Credit Agreement, Tranche A, US Dollar Denominated Term Loan [Member] 2023 Credit Agreement, Tranche A, US Dollar Denominated Term Loan Entity Address, Address Line Two Entity Address, Address Line Two Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Right-of-use assets obtained in exchange for new finance lease liabilities Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Other Temporary Equity, Other Changes Current Assets: Assets, Current [Abstract] Proceeds from disposition of real estate assets Proceeds from Sale, Real Estate, Held-for-Investment Accrued loan loss Loan Loss Sharing Reserve The reporting entity's estimate of loss sharing reserves on loans originated that are subject to a loss sharing arrangement with a third party. Derivative liabilities Derivative Liability Non-PEO NEO Non-PEO NEO [Member] Senior notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Right-of-use assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability TD Bank, Pricing Warehouse Line Of Credit Five [Member] Warehouse line of credit five. Line of credit facility outstanding Line of Credit Facility, Fair Value of Amount Outstanding Provision for income taxes Income Tax Expense (Benefit) Real estate investments Real Estate Investments [Member] Real Estate Investments . Foreign currency transaction gains and losses resulting in a net gain (loss) Gain (Loss), Foreign Currency Transaction, before Tax 4.800% senior notes due 2030 Senior Notes, Four Point Eight Percent [Member] Senior Notes, Four Point Eight Percent Fair Value Hedge Fair Value Hedging [Member] Award Timing Method Award Timing Method [Text Block] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] NET CHANGE IN CASH, 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] Valuation Valuation [Member] Valuation. Deferred Consideration Deferred Consideration [Member] Deferred Consideration Deferred tax and other liabilities Business Combination, Recognized Liability Assumed, Deferred Tax Liability New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Net income attributable to CBRE Group, Inc. Net income attributable to CBRE Group, Inc. stockholders Net income attributable to CBRE Group, Inc. Net Income (Loss) Attributable to Parent Long-term Debt, Type Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Less: unamortized debt issuance costs Unamortized Debt Issuance Expense Location, Statement of Financial Position, Balance [Axis] Location, Statement of Financial Position, Balance [Axis] Statement [Table] Statement [Table] Receivables, prepaid expenses and other assets Increase Decrease In Receivables Prepaid Expenses And Other Assets Including Contract Assets Increase decrease in receivables, prepaid expenses and other assets (including contract assets). Restatement Determination Date: Restatement Determination Date [Axis] Liabilities Assumed: Business Combination, Recognized Liability Assumed, Liability [Abstract] Management agreements Management Agreements [Member] Management Agreements Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Fed funds effective rate overnight index swap rate Fed Funds Effective Rate Overnight Index Swap Rate [Member] Contingently Issuable Shares Share-Based Payment Arrangement [Member] Earnings Per Share And Stockholders Equity [Abstract] Earnings Per Share And Stockholders Equity [Abstract] Earnings per share and stockholders' equity. Bank of America, Pricing Warehouse Line Of Credit Six [Member] Warehouse line of credit six. Current: Lease Liabilities Current [Abstract] Lease liabilities current. Investments in unconsolidated subsidiaries Investments in Affiliates, Subsidiaries, Associates, and Joint Ventures, Fair Value Disclosure Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Semi-annual basis adjustment (basis points) Debt Instrument, Redemption Price, Semi-Annual Basis Adjustment, Percent Debt Instrument, Redemption Price, Semi-Annual Basis Adjustment, Percent Derivative Instruments and Hedging Activities Disclosure [Abstract]