v3.22.2.2
Document and Entity Information
Sep. 17, 2022
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0000887343
Document Type 8-K
Document Period End Date Sep. 17, 2022
Entity Registrant Name COLUMBIA BANKING SYSTEM, INC.
Entity Incorporation State Country Code WA
Entity File Number 000-20288
Entity Tax Identification Number 91-1422237
Entity Address, Address Line One 1301 A Street
Entity Address, City or Town Tacoma
Entity Address, State or Province WA
Entity Address, Postal Zip Code 98402-2156
City Area Code (253)
Local Phone Number 305-1900
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, No Par Value
Trading Symbol COLB
Security Exchange Name NASDAQ
Entity Emerging Growth Company false