The description of non-current assets or disposal groups that have been either classified as held for sale or sold. [Refer: Non-current assets or disposal groups classified as held for sale; Disposal groups classified as held for sale [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2020-01-01
-Paragraph 41
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2020-en-r&anchor=para_41_a&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_DescriptionOfNoncurrentAssetOrDisposalGroupHeldForSaleWhichWereSoldOrReclassified
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of non-current assets or disposal groups classified as held for sale. [Refer: Disposal groups classified as held for sale [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2020-01-01
-Paragraph 38
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2020-en-r&anchor=para_38&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSale
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash inflow from sales of interests in associates. [Refer: Associates [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_16&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ProceedsFromSalesOfInterestsInAssociates
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Assets held for sale.

+ References

No definition available.

+ Details

Name:	ntz_AssetsHeldForSaleLineItems
Namespace Prefix:	ntz_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash consideration from disposal of non current assets classified as held for sale and discontinued operations.

+ References

No definition available.

+ Details

Name:	ntz_CashConsiderationFromDisposalOfNonCurrentAssetsClassifiedAsHeldForSaleAndDiscontinuedOperations
Namespace Prefix:	ntz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Disposal group assets held for sale, consideration agreed.

+ References

No definition available.

+ Details

Name:	ntz_DisposalGroupAssetsHeldForSaleConsiderationAgreed
Namespace Prefix:	ntz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Disposal group assets held for sale, cumulative income (expense) included in OCI.

+ References

No definition available.

+ Details

Name:	ntz_DisposalGroupAssetsHeldForSaleCumulativeIncomeExpenseIncludedInOCI
Namespace Prefix:	ntz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Disposal group assets held for sale, ownership percentage upon closing of sale transaction.

+ References

No definition available.

+ Details

Name:	ntz_DisposalGroupAssetsHeldForSaleOwnershipPercentageUponClosingOfSaleTransaction
Namespace Prefix:	ntz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Disposal group assets held for sale, purchase price adjustments.

+ References

No definition available.

+ Details

Name:	ntz_DisposalGroupAssetsHeldForSalePurchasePriceAdjustments
Namespace Prefix:	ntz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of noncurrent assets held for sale.

+ References

No definition available.

+ Details

Name:	ntz_NumberOfNoncurrentAssetsHeldForSale
Namespace Prefix:	ntz_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_AssetsAndLiabilitiesClassifiedAsHeldForSaleAxis=ifrs-full_NoncurrentAssetsHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ntz_IndustrialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=ifrs-full_ClassificationOfAssetsAsHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ntz_IndustrialRealEstateComplexViaDellAvenaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ntz_IndustrialRealEstateComplexFornelloMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CounterpartiesAxis=ntz_VitaGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfContractsAxis=ntz_ShareSellAndPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_AssetsAndLiabilitiesClassifiedAsHeldForSaleAxis=ifrs-full_DisposalGroupsClassifiedAsHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=ntz_IMPESPAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Assets Held for Sale - Additional Information (Detail)		1 Months Ended		12 Months Ended
Assets Held for Sale - Additional Information (Detail)	Jan. 08, 2021 EUR (€)	Mar. 31, 2021 EUR (€)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 EUR (€) Asset	Mar. 01, 2021
Non-current Assets Held For Sale [member] \| Industrial Real Estate Complex [member]
Assets Held For Sale [Line Items]
Cash consideration on disposal of non-current assets held for sale			€ 1,300,000	€ 1,300,000
Non-current Assets Held For Sale [member] \| Classification of Assets as Held For Sale [member] \| Industrial Real Estate Complex Via Dell Avena [member]
Assets Held For Sale [Line Items]
Description of non-current asset or disposal group held for sale which were sold or reclassified				Parent signed the preliminary agreement with a third party for the disposal of the idle industrial real estate complex “Via Dell’Avena” located in the city of Altamura (Bari), just a few miles away from its headquarters
Cash consideration on disposal of non-current assets held for sale			1,300,000	€ 1,300,000
Non-current assets or disposal groups classified as held for sale			820,000	€ 820,000
Non-current Assets Held For Sale [member] \| Classification of Assets as Held For Sale [member] \| Industrial Real Estate Complex Fornello [member]
Assets Held For Sale [Line Items]
Description of non-current asset or disposal group held for sale which were sold or reclassified				Parent signed the sale contract with a third party for the disposal of the idle industrial real estate complex “Fornello” located in the city of Altamura (Bari), just a few miles away from its headquarters
Cash consideration on disposal of non-current assets held for sale		€ 1,250,000
Non-current assets or disposal groups classified as held for sale			€ 884,000	€ 884,000
Non-current Assets Held For Sale [member] \| Classification of Assets as Held For Sale [member] \| Industrial Real Estate Complex [member]
Assets Held For Sale [Line Items]
Description of non-current asset or disposal group held for sale which were sold or reclassified		Parent signed the sale contract with a third party for the disposal of the idle industrial real estate complex “Fornello” located in the city of Altamura (Bari), just a few miles away from its headquarters.	Parent signed the preliminary agreement with a third party for the disposal of the idle industrial real estate complex “Via Dell’Avena” located in the city of Altamura (Bari), just a few miles away from its headquarters	Parent signed the sale contract with a third party for the disposal of the idle industrial real estate complex “Fornello”, located in the city of Altamura (Bari), just a few miles away from its headquarters.
Cash consideration on disposal of non-current assets held for sale		€ 1,250,000	€ 1,300,000	€ 1,300,000
Number of noncurrent assets held for sale \| Asset				2
Vita Group [member] \| Share Sell and Purchase Agreement [member] \| Disposal Groups Classified as Held For Sale [member] \| IMPE S.p.A. [member]
Assets Held For Sale [Line Items]
Disposal group assets held for sale, cumulative income (expense) included in OCI				€ 0
Vita Group [member] \| Share Sell and Purchase Agreement [member] \| Disposal Groups Classified as Held For Sale [member] \| IMPE S.p.A. [member] \| Classification of Assets as Held For Sale [member]
Assets Held For Sale [Line Items]
Disposal group assets held for sale, consideration agreed	€ 6,100,000
Disposal group assets held for sale purchase price adjustments	1,800,000
Disposal group assets held for sale, ownership percentage upon closing of sale transaction					100.00%
Disposal group assets held for sale cash consideration received	€ 4,900,000