Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Beginning balance, goodwill gross	$ 5,968	$ 5,851
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	5,956	5,839
Additions/ adjustments	15	3
Foreign currency translation adjustments	(62)	114
Ending balance, goodwill gross	5,921	5,968
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	5,909	5,956
MA
Goodwill [Roll Forward]
Beginning balance, goodwill gross	5,681	5,474
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	5,669	5,462
Additions/ adjustments	13	90
Foreign currency translation adjustments	(61)	117
Ending balance, goodwill gross	5,633	5,681
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	5,621	5,669
MIS
Goodwill [Roll Forward]
Beginning balance, goodwill gross	287	377
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	287	377
Additions/ adjustments	2	(87)
Foreign currency translation adjustments	(1)	(3)
Ending balance, goodwill gross	288	287
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	$ 288	$ 287