Derivatives - Schedule of Pretax Effects of Derivative Financial Instruments Designated as Effective Hedges (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	$ (38.9)	$ (69.8)	$ 10.0
Gain/(Loss) Reclassified from AOCI to Income	(8.3)	(12.0)	14.3
Interest Rate Swaps [Member] \| Interest Expense, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)		(88.1)	(3.1)
Gain/(Loss) Reclassified from AOCI to Income	(8.2)	(6.2)	(0.8)
Foreign Currency Contracts [Member] \| Sales and Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	(33.1)	31.3	15.8
Gain/(Loss) Reclassified from AOCI to Income	6.8	7.4	16.1
Cross-currency Swaps [Member] \| Other Income (Expense), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	(5.8)	(13.0)	(2.7)
Gain/(Loss) Reclassified from AOCI to Income	$ (6.9)	$ (13.2)	$ (1.0)

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.

No definition available.

+ Details

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

- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=nwl_CrossCurrencyInterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=nwl_OtherIncomeExpenseNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: