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Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Goodwill [Roll Forward]
Beginning balance, goodwill gross	$ 6,006	$ 5,968
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	5,994	5,956
Additions/ adjustments	135	209
Foreign currency translation adjustments	108	(171)
Ending balance, goodwill gross	6,249	6,006
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	6,237	5,994
MA
Goodwill [Roll Forward]
Beginning balance, goodwill gross	5,626	5,681
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	5,614	5,669
Additions/ adjustments	135	112
Foreign currency translation adjustments	111	(167)
Ending balance, goodwill gross	5,872	5,626
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	5,860	5,614
MIS
Goodwill [Roll Forward]
Beginning balance, goodwill gross	380	287
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	380	287
Additions/ adjustments	0	97
Foreign currency translation adjustments	(3)	(4)
Ending balance, goodwill gross	377	380
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	$ 377	$ 380

X

- 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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