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Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Beginning balance, goodwill gross		$ 5,851
Beginning balance, Accumulated impairment charge		(12)
Beginning balance, goodwill net		5,839
Additions/ adjustments	$ 137	3
Foreign currency translation adjustments	55	114
Ending balance, goodwill gross	6,160	5,968
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	6,148	5,956
MA
Goodwill [Roll Forward]
Beginning balance, goodwill gross		5,474
Beginning balance, Accumulated impairment charge		(12)
Beginning balance, goodwill net		5,462
Additions/ adjustments	39	90
Foreign currency translation adjustments	54	117
Ending balance, goodwill gross	5,774	5,681
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	5,762	5,669
MIS
Goodwill [Roll Forward]
Beginning balance, goodwill gross		377
Beginning balance, Accumulated impairment charge		0
Beginning balance, goodwill net		377
Additions/ adjustments	98	(87)
Foreign currency translation adjustments	1	(3)
Ending balance, goodwill gross	386	287
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	$ 386	$ 287

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- Definition

Goodwill additions and adjustments during the period, including the reallocation of goodwill pursuant to a realignment of certain components of the Company's ESG business in 2023.

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Amount, after 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.

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