Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2026	Dec. 31, 2025
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 7,051
Reallocation	0
Acquisitions	7
Foreign exchange movement	(66)
Goodwill, gross, ending balance	6,992
Advisory Services
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	2,401
Reallocation	0
Acquisitions	(4)
Foreign exchange movement	(11)
Goodwill, gross, ending balance	2,386
Accumulated impairment losses		$ (673)
Building Operations & Experience
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	2,850
Reallocation	27
Acquisitions	5
Foreign exchange movement	(29)
Goodwill, gross, ending balance	2,853
Accumulated impairment losses		(175)
Project Management
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,378
Reallocation	(27)
Acquisitions	6
Foreign exchange movement	(21)
Goodwill, gross, ending balance	1,336
Accumulated impairment losses		(89)
Real Estate Investments
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	422
Reallocation	0
Acquisitions	0
Foreign exchange movement	(5)
Goodwill, gross, ending balance	$ 417
Accumulated impairment losses		$ (183)

Goodwill Reallocation

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) asset representing future economic benefit from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

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- Definition

Amount, before accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Includes amount, before amortization expense and impairment loss, of goodwill for private company.

+ References

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- Definition

Amount of accumulated impairment loss for asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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- Definition

Amount of increase (decrease) from measurement period adjustment of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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