Debt instrument maturity year.

No definition available.

Name:	nlsnnv_DebtInstrumentMaturityYear
Namespace Prefix:	nlsnnv_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorSecuredTermLoanDueTwoThousandAndTwentyThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=nlsnnv_LIBORBasedVariableRateOfThreePointFourSixPercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=nlsnnv_LIBORBasedVariableRateOfThreePointSevenOnePercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=nlsnnv_EuroLIBORBasedVariableRateOfTwoPointFiveZeroPercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorSecuredRevolvingCreditFacilityDueTwoThousandAndTwentyThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=nlsnnv_EuroLIBOROrLIBORBasedVariableRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorDebentureLoanDueTwoThousandAndTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorDebentureLoanDueTwoThousandAndTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorDebentureLoanDueTwoThousandAndTwentyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlsnnv_SeniorDebentureLoanDueTwoThousandAndTwentyFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-term Debt and Other Financing Arrangements - Summary of Long-Term Debt (Parenthetical) (Detail) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2018 EUR (€)
Senior Secured Term Loan Facility Due 2023 \| Libor Based Variable Rate of 3.46%
Debt Instrument [Line Items]
Debt instrument face value	$ 1,125	$ 1,125
Debt instrument, variable rate	3.46%	3.46%
Debt instrument, maturity year	2023	2023
Senior Secured Term Loan Facility Due 2023 \| Libor Based Variable Rate of 3.71%
Debt Instrument [Line Items]
Debt instrument face value	$ 2,303	$ 2,303
Debt instrument, variable rate	3.71%	3.71%
Debt instrument, maturity year	2023	2023
Senior Secured Term Loan Facility Due 2023 \| Euro Libor Based Variable Rate of 2.50%
Debt Instrument [Line Items]
Debt instrument face value \| €			€ 545	€ 545
Debt instrument, variable rate	2.50%	2.50%
Debt instrument, maturity year	2023	2023
Senior Secured Revolving Credit Facility Due 2023 \| Euro Libor or Libor based variable rate
Debt Instrument [Line Items]
Debt instrument face value	$ 850	$ 850
Debt instrument, maturity year	2023	2023
Senior Debenture Loan Due 2020
Debt Instrument [Line Items]
Debt instrument face value	$ 800	$ 800
Debt instrument, maturity year	2020	2020
Debt instrument interest rate stated percentage	4.50%	4.50%	4.50%	4.50%
Senior debenture loan due 2021
Debt Instrument [Line Items]
Debt instrument face value	$ 625	$ 625
Debt instrument, maturity year	2021	2021
Debt instrument interest rate stated percentage	5.50%	5.50%	5.50%	5.50%
Senior Debenture Loan Due 2022
Debt Instrument [Line Items]
Debt instrument face value	$ 2,300	$ 2,300
Debt instrument, maturity year	2022	2022
Debt instrument interest rate stated percentage	5.00%	5.00%	5.00%	5.00%
Senior Debenture Loan Due 2025
Debt Instrument [Line Items]
Debt instrument face value	$ 500	$ 500
Debt instrument, maturity year	2025	2025
Debt instrument interest rate stated percentage	5.00%	5.00%	5.00%	5.00%