Segments - Business Segment Information (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting [Abstract]
Revenues		$ 863	$ 842
Operating income		253	177
Depreciation and amortization		127	136
Restructuring charges			3
Share-based compensation expense		7	10
Dis-synergy costs	[1]		(17)
Other items	[2]	1	17
Business segment income	[3]	388	$ 326
Assets:
Total assets		$ 11,884		$ 11,146

[1] Costs to stand-up Nielsen as a standalone company including incremental real estate, IT/infrastructure, Transition Services Agreements and commercial arrangements.

[2] Other items primarily consist of business optimization costs and transaction related costs for the three months ended March 31, 2021 and 2020, respectively.

[3] The CODM uses business segment income/(loss) to measure performance from period to period.