v3.25.3
Cover Page - shares
9 Months Ended
Sep. 30, 2025
Nov. 06, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2025  
Document Transition Report false  
Entity File Number 001-38671  
Entity Registrant Name CAPITAL BANCORP INC  
Entity Incorporation, State or Country Code MD  
Entity Tax Identification Number 52-2083046  
Entity Address, Address Line One 2275 Research Boulevard  
Entity Address, Address Line Two Suite 600  
Entity Address, City or Town Rockville  
Entity Address, State or Province MD  
Entity Address, Postal Zip Code 20850  
City Area Code 301  
Local Phone Number 468-8848  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol CBNK  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   16,520,863
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Entity Central Index Key 0001419536  
Current Fiscal Year End Date --12-31