Revenue Recognition - Summary of Revenue Disaggregated by Segment by Major Product Offerings and Timing of Revenue Recognition (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	$ 1,616	$ 1,600	$ 4,807	$ 4,857
Operating Segments | Products Transferred at a Point in Time
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	138	140	409	420
Operating Segments | Products and Services Transferred Over Time
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	1,478	1,460	4,398	4,437
Connect | Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	746	763	2,255	2,349
Connect | Operating Segments | Measure
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	530	545	1,615	1,668
Connect | Operating Segments | Predict/Activate
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	216	218	640	681
Media | Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	870	837	2,552	2,508
Media | Operating Segments | Audience Measurement
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	621	596	1,848	1,793
Media | Operating Segments | Plan/Optimize
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	$ 249	$ 241	$ 704	$ 715