Revenues - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Revenue	$ 1,817	$ 1,494	$ 3,603	$ 2,964
MA
Segment Reporting Information [Line Items]
Revenue	802	747	1,601	1,484
MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	806	751	1,608	1,491
MIS
Segment Reporting Information [Line Items]
Revenue	1,015	747	2,002	1,480
MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,064	793	2,098	1,571
United States
Segment Reporting Information [Line Items]
Revenue	974	775	1,943	1,538
United States | MA
Segment Reporting Information [Line Items]
Revenue	338	320	675	637
United States | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	338	320	675	637
United States | MIS
Segment Reporting Information [Line Items]
Revenue	636	455	1,268	901
United States | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	636	455	1,268	901
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	843	719	1,660	1,426
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	464	427	926	847
Non-U.S. | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	464	427	926	847
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	379	292	734	579
Non-U.S. | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	379	292	734	579
EMEA
Segment Reporting Information [Line Items]
Revenue	566	479	1,108	939
EMEA | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	319	298	635	585
EMEA | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	247	181	473	354
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	164	145	319	294
Asia-Pacific | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	82	70	167	148
Asia-Pacific | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	82	75	152	146
Americas
Segment Reporting Information [Line Items]
Revenue	113	95	233	193
Americas | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	63	59	124	114
Americas | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	$ 50	$ 36	$ 109	$ 79