v3.26.1
Document and Entity Information Document
May 28, 2026
Document and Entity Information [Abstract]  
Entity Emerging Growth Company false
Title of 12(b) Security Common Stock
Entity File Number 1-38681
Document Type 8-K
Document Period End Date May 28, 2026
Entity Registrant Name NORTHWEST NATURAL HOLDING COMPANY
Entity Incorporation, State or Country Code OR
Entity Tax Identification Number 82-4710680
Entity Address, Address Line One 250 S.W. Taylor Street
Entity Address, City or Town Portland
Entity Address, State or Province OR
Entity Address, Postal Zip Code 97204
City Area Code (503)
Local Phone Number 226-4211
Trading Symbol NWN
Security Exchange Name NYSE
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Central Index Key 0001733998
Amendment Flag false