Debt Instrument, Principal Amount Issued, Percentage Of Face Value

No definition available.

Name:	cbre_DebtInstrumentPrincipalAmountIssuedPercentageOfFaceValue
Namespace Prefix:	cbre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Maximum Borrowing Capacity Increase (Decrease)

+ References

No definition available.

+ Details

Name:	cbre_LineOfCreditFacilityMaximumBorrowingCapacityIncreaseDecrease
Namespace Prefix:	cbre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long term debt percentage spread over daily interest rate.

+ References

No definition available.

+ Details

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

- Definition

Long term debt percentage spread over fixed interest rate.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

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

- Definition

This element represents the minimum ratio of earnings before interest, taxes, depreciation and amortization (EBITDA) to total interest expense required in the reporting entity's credit agreement.

+ References

No definition available.

+ Details

Name:	cbre_MinimumCoverageRatioOfEarningsBeforeInterestTaxDepreciationAndAmortizationToInterestExpenseExpressedInPercentage
Namespace Prefix:	cbre_
Data Type:	dtr-types:percentItemType
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

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI https://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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 carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

Name:	us-gaap_LineOfCredit
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

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=cbre_TwoThousandTwentyOneCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=cbre_TwoPointFivePercentSeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=cbre_FourPointEightSevenFiveSeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=cbre_TwoThousandNineteenCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=cbre_RevolvingCreditFacilityMaturityDateAugust52027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=cbre_EuroTermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=cbre_EuropeInterbankOfferedRateEURIBORMember
Namespace Prefix:
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Long-Term Debt and Short-Term Borrowings - Long-Term Debt - Narrative (Details)			3 Months Ended
	Aug. 05, 2022 USD ($)	Aug. 13, 2015 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 EUR (€)	Jul. 09, 2021 USD ($)	May 21, 2021 USD ($)	Mar. 18, 2021 USD ($)
2021 Credit Agreement
Debt Instrument [Line Items]
Minimum coverage ratio of EBITDA to total interest expense expressed in percentage			2.00%
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%
2.500% Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount							$ 500,000,000
Interest rate			2.50%	2.50%			2.50%
Percentage of face value							98.451%
4.875% Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 600,000,000
Interest rate		4.875%	4.875%	4.875%
Redemption price percentage		99.24%
Revolving credit facility \| 2019 Credit Agreement
Debt Instrument [Line Items]
Aggregate principal amount					$ 350,000,000
Revolving credit facility \| 2021 Credit Agreement
Debt Instrument [Line Items]
Debt agreement term	5 years
Amounts available to borrow under credit agreement						$ 3,150,000,000
Revolving credit facility \| 2021 Credit Agreement \| Minimum
Debt Instrument [Line Items]
Credit agreement applicable fixed rate spread			0.68%
Credit agreement applicable daily rate spread			0.00%
Revolving credit facility \| 2021 Credit Agreement \| Maximum
Debt Instrument [Line Items]
Credit agreement applicable fixed rate spread			1.075%
Credit agreement applicable daily rate spread			0.075%
Revolving credit facility \| Revolving Credit Agreement
Debt Instrument [Line Items]
Debt agreement term	5 years
Amounts available to borrow under credit agreement	$ 3,500,000,000
Interest rate	1000.00%
Euro term loan facility \| 2021 Credit Agreement
Debt Instrument [Line Items]
Aggregate principal amount \| €				€ 400,000,000
Borrowings outstanding			$ 433,400,000
Euro term loan facility \| 2021 Credit Agreement \| Senior Notes \| Minimum \| Europe Interbank Offered Rate (EURIBOR)
Debt Instrument [Line Items]
Variable rate (as a percent)			0.75%