v3.26.1
Cover - shares
 3 Months Ended
Mar. 31, 2026
May 13, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Amendment Flag false  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Entity Information [Line Items]    
Entity Registrant Name Commercial Bancgroup, Inc.  
Entity Central Index Key 0001981546  
Entity File Number 001-42889  
Entity Tax Identification Number 62-1039469  
Entity Incorporation, State or Country Code TN  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Contact Personnel [Line Items]    
Entity Address, Address Line One 6710 Cumberland Gap Parkway  
Entity Address, City or Town Harrogate  
Entity Address, State or Province TN  
Entity Address, Postal Zip Code 37752  
Entity Phone Fax Numbers [Line Items]    
City Area Code (423)  
Local Phone Number 869-5151  
Entity Listings [Line Items]    
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol CBK  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding   13,701,269