Changes in and Reclassification out of Accumulated Other Comprehensive Income/(Loss) by Component - Summary of Changes in Accumulated Other Comprehensive Income/(Loss), Net of Tax by Component (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	$ 2,243	$ 2,388
Amounts reclassified from accumulated other comprehensive (income)/loss	381	4
Total other comprehensive income/(loss)	377	(133)
Balance	3,170	2,231
Currency Translation Adjustments
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	(821)	(776)
Other comprehensive income/(loss) before reclassifications	(5)	(104)
Amounts reclassified from accumulated other comprehensive (income)/loss	233
Total other comprehensive income/(loss)	228	(104)
Net current period other comprehensive income/(loss) attributable to noncontrolling interest	(2)	(8)
Net current period other comprehensive income/(loss) attributable to Nielsen shareholders	230	(96)
Balance	(591)	(872)
Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	(39)	(19)
Other comprehensive income/(loss) before reclassifications	1	(34)
Amounts reclassified from accumulated other comprehensive (income)/loss	4	1
Total other comprehensive income/(loss)	5	(33)
Net current period other comprehensive income/(loss) attributable to Nielsen shareholders	5	(33)
Balance	(34)	(52)
Post-Employment Benefits
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	(245)	(210)
Other comprehensive income/(loss) before reclassifications		1
Amounts reclassified from accumulated other comprehensive (income)/loss	144	3
Total other comprehensive income/(loss)	144	4
Net current period other comprehensive income/(loss) attributable to Nielsen shareholders	144	4
Balance	(101)	(206)
AOCI Including Portion Attributable to Noncontrolling Interest
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Balance	(1,105)	(1,005)
Other comprehensive income/(loss) before reclassifications	(4)	(137)
Amounts reclassified from accumulated other comprehensive (income)/loss	381	4
Total other comprehensive income/(loss)	377	(133)
Net current period other comprehensive income/(loss) attributable to noncontrolling interest	(2)	(8)
Net current period other comprehensive income/(loss) attributable to Nielsen shareholders	379	(125)
Balance	$ (726)	$ (1,130)