Document and Entity Information
12 Months Ended
Dec. 31, 2014
Document And Entity Information [Abstract]  
Document Type S-1/A
Amendment Flag false
Document Period End Date Dec. 31, 2014
Document Fiscal Year Focus 2014
Document Fiscal Period Focus FY
Entity Registrant Name NATIONAL COMMERCE CORPORATION
Entity Central Index Key 0001609951
Current Fiscal Year End Date --12-31
Entity Filer Category Smaller Reporting Company