Goodwill And Other Acquired Intangible Assets - Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 2,510	$ 1,824
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	2,108	1,623
Accumulated amortization	(360)	(313)
Acquired intangible assets, net	1,748	1,310
Software/product technology
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	654	441
Accumulated amortization	(203)	(177)
Acquired intangible assets, net	451	264
Database
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	180	144
Accumulated amortization	(42)	(29)
Acquired intangible assets, net	138	115
Trade names
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	207	161
Accumulated amortization	(44)	(38)
Acquired intangible assets, net	163	123
Other
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	54	55
Accumulated amortization	(44)	(43)
Acquired intangible assets, net	$ 10	$ 12