Revenues - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,553	$ 1,435	$ 3,153	$ 2,725
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	706	684	1,480	1,242
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	847	751	1,673	1,483
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	980	938	2,016	1,732
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	686	664	1,431	1,183
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	294	274	585	549
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	573	497	1,137	993
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	20	20	49	59
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 553	$ 477	$ 1,088	$ 934