Revenues - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,435	$ 1,214	$ 2,725	$ 2,356
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	684	500	1,242	940
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	751	714	1,483	1,416
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	938	739	1,732	1,409
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	664	478	1,183	888
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	274	261	549	521
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	497	475	993	947
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	20	22	59	52
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 477	$ 453	$ 934	$ 895