Represents the number of equal quarterly installments in which debt instrument will be due.

No definition available.

Name:	np_DebtInstrumentDueNumberOfEqualQuarterlyInstallments
Namespace Prefix:	np_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=np_NewSeniorNotesDueMay2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=np_NeenahSecondGermanyProjectFinancing2.5PercentDueSeptember2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=np_GlobalRevolvingCreditFacilitiesDueDecember2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary of Significant Accounting Policies - Fair Value of Financial Instruments (Details) $ in Millions	Dec. 31, 2018 USD ($) installment	Sep. 30, 2018	Dec. 31, 2017 USD ($)	May 31, 2013
Marketable securities
Cost of marketable securities	$ 4.3
Senior notes \| 2021 Senior Notes (5.25% fixed rate) due May 2021
Fair Value of Financial Instruments
Fixed rate of interest (as a percent)	5.25%			5.25%
Secured debt \| Second German Loan Agreement (2.45% fixed rate) due in quarterly installments ending September 2022
Fair Value of Financial Instruments
Fixed rate of interest (as a percent)	2.45%
Number of quarterly installments \| installment	32
Secured debt \| Third German Loan Agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Fixed rate of interest (as a percent)	1.45%	1.45%
Number of quarterly installments \| installment	16
Carrying Value
Fair Value of Financial Instruments
Debt fair value	$ 242.6		$ 258.3
Carrying Value \| Senior notes \| 2021 Senior Notes (5.25% fixed rate) due May 2021
Fair Value of Financial Instruments
Debt fair value	175.0		175.0
Carrying Value \| Line of credit \| Global Revolving Credit Facilities (variable rates) due December 2023
Fair Value of Financial Instruments
Debt fair value	57.9		76.9
Carrying Value \| Secured debt \| Second German Loan Agreement (2.45% fixed rate) due in quarterly installments ending September 2022
Fair Value of Financial Instruments
Debt fair value	4.8		6.4
Carrying Value \| Secured debt \| Third German Loan Agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Debt fair value	4.9		0.0
Fair Value \| Level 1 \| Other assets
Marketable securities
Fair value of marketable securities	3.6
Fair Value \| Level 2
Fair Value of Financial Instruments
Debt fair value	238.4		253.5
Fair Value \| Level 2 \| Senior notes \| 2021 Senior Notes (5.25% fixed rate) due May 2021
Fair Value of Financial Instruments
Debt fair value	170.5		170.2
Fair Value \| Level 2 \| Line of credit \| Global Revolving Credit Facilities (variable rates) due December 2023
Fair Value of Financial Instruments
Debt fair value	57.9		76.9
Fair Value \| Level 2 \| Secured debt \| Second German Loan Agreement (2.45% fixed rate) due in quarterly installments ending September 2022
Fair Value of Financial Instruments
Debt fair value	5.1		6.4
Fair Value \| Level 2 \| Secured debt \| Third German Loan Agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Debt fair value	$ 4.9		$ 0.0