Revenues - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 5,916	$ 5,468	$ 6,218
Operating Segments
Segment Reporting Information [Line Items]
Revenue	5,916	5,468	6,218
MA
Segment Reporting Information [Line Items]
Revenue	3,056	2,769	2,406
MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	3,069	2,777	2,413
MIS
Segment Reporting Information [Line Items]
Revenue	2,860	2,699	3,812
MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	3,046	2,873	3,977
U.S.
Segment Reporting Information [Line Items]
Revenue	3,098	2,873	3,383
U.S. | MA
Segment Reporting Information [Line Items]
Revenue	1,348	1,239	1,039
U.S. | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,348	1,239	1,039
U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	1,750	1,634	2,344
U.S. | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,750	1,634	2,344
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	2,818	2,595	2,835
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	1,708	1,530	1,367
Non-U.S. | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,708	1,530	1,367
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	1,110	1,065	1,468
Non-U.S. | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,110	1,065	1,468
EMEA
Segment Reporting Information [Line Items]
Revenue	1,848	1,682	1,885
EMEA | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	1,169	1,034	955
EMEA | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	679	648	930
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	577	556	603
Asia-Pacific | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	306	285	246
Asia-Pacific | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	271	271	357
Americas
Segment Reporting Information [Line Items]
Revenue	393	357	347
Americas | MA | Operating Segments
Segment Reporting Information [Line Items]
Revenue	233	211	166
Americas | MIS | Operating Segments
Segment Reporting Information [Line Items]
Revenue	$ 160	$ 146	$ 181