v3.25.2
Document And Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Aug. 08, 2025
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-38999  
Entity Registrant Name BioCardia, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 23-2753988  
Entity Address, Address Line One 320 Soquel Way  
Entity Address, City or Town Sunnyvale  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94085  
City Area Code 650  
Local Phone Number 226-0120  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Title of 12(b) Security Common Stock, par value $0.001  
Trading Symbol BCDA  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding (in shares)   5,801,224
Entity Central Index Key 0000925741  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false