Restructuring Costs - Schedule of Accrued Restructuring Costs Activity (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Non-cash restructuring charges	$ 22.2	$ 10.3

Non-cash portion of amounts charged against earnings in the period for incurred and estimated costs associated with exits from business activities, disposals of assets, and restructurings pursuant to a program that is planned and controlled by management, and materially changes either the scope of a business undertaken by an entity or the manner in which that business is conducted.

No definition available.

Name:	nwl_NonCashPortionOfRestructuringChargesNet
Namespace Prefix:	nwl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration