CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Pension liability adjustments, income tax expense (benefit)	$ 1.1	$ (0.7)	$ (5.2)
Income tax expense	$ (2.8)	$ 3.6	$ 0.6

Tax effect of the change in minimum pension liability.

No definition available.

Name:	cbre_OtherComprehensiveIncomeDefinedBenefitPlansTaxes
Namespace Prefix:	cbre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration