Condensed Consolidated Statements of Comprehensive Income/(Loss) (Unaudited) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income/(loss)		$ 103	$ 10	$ 757	$ (29)
Other comprehensive income/(loss), net of tax
Foreign currency translation adjustments	[1]	(20)		180	(90)
Changes in the fair value of cash flow hedges	[2]	5	6	14	(25)
Defined benefit pension plan adjustments	[3]	3	3	149	10
Total other comprehensive (loss)/income		(12)	9	343	(105)
Total comprehensive income/(loss)		91	19	1,100	(134)
Less: comprehensive income attributable to noncontrolling interests		1	5	6	7
Total comprehensive income/(loss) attributable to Nielsen shareholders		$ 90	$ 14	$ 1,094	$ (141)

[1] Net of tax of zero and $5 million for the three months ended September 30, 2021 and 2020, respectively, and $(1) million and $5 million for the nine months ended September 30, 2021 and 2020, respectively.

[2] Net of tax of $(1) million and $(2) million for the three months ended September 30, 2021 and 2020, respectively, and $(6) million and $10 million for the nine months ended September 30, 2021 and 2020, respectively.

[3] Net of tax of zero and $(1) million for the three months ended September 30, 2021 and 2020, respectively, and $(44) million and $(3) million for the nine months ended September 30, 2021 and 2020, respectively.