v3.25.1
Document And Entity Information
Jun. 03, 2025
Document Information [Line Items]  
Entity, Registrant Name NORTHWEST PIPE COMPANY
Document, Type 8-K
Document, Period End Date Jun. 03, 2025
Entity, Incorporation, State or Country Code OR
Entity, File Number 0-27140
Entity, Tax Identification Number 93-0557988
Entity, Address, Address Line One 201 NE Park Plaza Drive, Suite 100
Entity, Address, City or Town Vancouver
Entity, Address, State or Province WA
Entity, Address, Postal Zip Code 98684
City Area Code 360
Local Phone Number 397-6250
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock
Trading Symbol NWPX
Security Exchange Name NASDAQ
Entity, Emerging Growth Company false
Amendment Flag false
Entity, Central Index Key 0001001385