v3.26.1
Document and Entity Information Document
Jul. 16, 2026
Cover [Abstract]  
Document Type 8-K/A
Document Period End Date Jul. 16, 2026
Entity Registrant Name Commerce Bancshares, Inc.
Entity Incorporation, State or Country Code MO
Entity File Number 001-36502
Entity Tax Identification Number 43-0889454
Entity Address, Address Line One 1000 Walnut,
Entity Address, City or Town Kansas City,
Entity Address, State or Province MO
Entity Address, Postal Zip Code 64106
City Area Code 816
Local Phone Number 234-2000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security $5 Par Value Common Stock
Trading Symbol CBSH
Security Exchange Name NASDAQ
Entity Emerging Growth Company false
Amendment Flag true
Entity Central Index Key 0000022356
Amendment Description Subsequent to the issuance of the earnings release and furnishing with the original Form 8-K on July 16, 2026, the Company identified that the growth in assets under administration had been incorrectly described as growth over the same period in the prior year rather than growth over the prior quarter. Therefore, the Company has prepared and furnished as Exhibit 99.1 to this Current Report on Form 8-K/A a corrected earnings release for investors and analysts that highlights the Company's Second Quarter 2026 earnings. The amended earnings release corrects the description of growth in the Company’s assets under administration on the second page of the earnings release. The statement as corrected reads as follows: “Assets under administration grew $3.1 billion, or 3.4%, over the prior quarter.” Apart from the correction of this typographical error, there were no changes to the information provided in the original press release and slide presentation.