Maximum leverage ratio during first four quarter that qualified acquisition is consummated.

No definition available.

Name:	cbre_MaximumLeverageRatioDuringFirstFourQuarterThatQualifiedAcquisitionIsConsummated
Namespace Prefix:	cbre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

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Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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Balance Type:	credit
Period Type:	instant

- Details

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- Details

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Long-Term Debt and Short-Term Borrowings - Revolving Credit Facility Narrative (Details) - USD ($) $ in Millions	Jun. 24, 2025	Sep. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Letters of credit outstanding amount		$ 347
Revolving Credit Agreements \| Senior Notes
Debt Instrument [Line Items]
Maximum leverage ratio of total debt less available cash to EBITDA expressed in percentage	4.25%
Maximum leverage ratio during first four quarter that qualified acquisition is consummated	4.75%
364-Day Revolving Credit Agreement \| Senior Notes
Debt Instrument [Line Items]
Maximum leverage ratio of total debt less available cash to EBITDA expressed in percentage	4.25%
Maximum leverage ratio during first four quarter that qualified acquisition is consummated	4.75%
Revolving credit facilities \| Revolving Credit Agreements
Debt Instrument [Line Items]
Debt agreement term	5 years
Amounts available to borrow under credit agreement	$ 3,500
Revolving credit facilities \| Revolving Credit Agreements \| Line of Credit
Debt Instrument [Line Items]
Letters of credit outstanding amount	300
Revolving credit facilities \| Revolving Credit Agreements \| Swingline Loans
Debt Instrument [Line Items]
Letters of credit outstanding amount	$ 300
Revolving credit facilities \| Revolving Credit Agreements \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap
Debt Instrument [Line Items]
Variable rate (as a percent)	1.00%
Revolving credit facilities \| Revolving Credit Agreements \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap \| Minimum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.63%
Revolving credit facilities \| Revolving Credit Agreements \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap \| Maximum
Debt Instrument [Line Items]
Variable rate (as a percent)	1.10%
Revolving credit facilities \| Revolving Credit Agreements \| Base Rate \| Minimum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.00%
Revolving credit facilities \| Revolving Credit Agreements \| Base Rate \| Maximum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.10%
Revolving credit facilities \| Revolving Credit Agreements \| Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Variable rate (as a percent)	0.50%
Revolving credit facilities \| 2019 Credit Agreement
Debt Instrument [Line Items]
Line of credit facility outstanding		0	$ 132
Revolving credit facilities \| 2019 Credit Agreement \| Line of Credit
Debt Instrument [Line Items]
Letters of credit outstanding amount		61	$ 0
Revolving credit facilities \| 364-Day Revolving Credit Agreement
Debt Instrument [Line Items]
Debt agreement term	364 days
Amounts available to borrow under credit agreement	$ 1,000
Line of credit facility outstanding		$ 0
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap
Debt Instrument [Line Items]
Variable rate (as a percent)	1.00%
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap \| Minimum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.645%
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap \| Maximum
Debt Instrument [Line Items]
Variable rate (as a percent)	1.125%
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Base Rate \| Minimum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.00%
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Base Rate \| Maximum
Debt Instrument [Line Items]
Variable rate (as a percent)	0.10%
Revolving credit facilities \| 364-Day Revolving Credit Agreement \| Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Variable rate (as a percent)	0.50%