Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Dec. 31, 2019
Feb. 21, 2020
Jun. 30, 2019
Document Information [Line Items]      
Entity Central Index Key 0001430723    
Entity Registrant Name ServisFirst Bancshares, Inc.    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2019    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2019    
Document Transition Report false    
Entity File Number 001-36452    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 26-0734029    
Entity Address, Address Line One 2500 Woodcrest Place    
Entity Address, City or Town Birmingham    
Entity Address, State or Province AL    
Entity Address, Postal Zip Code 35209    
City Area Code 205    
Local Phone Number 949-0302    
Title of 12(b) Security Common stock, par value $.001 per share    
Trading Symbol SFBS    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 1,581,146,000
Entity Common Stock, Shares Outstanding   53,703,632