Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Feb. 25, 2019
Jun. 30, 2018
Document Information [Line Items]      
Entity Registrant Name ServisFirst Bancshares, Inc.    
Entity Central Index Key 0001430723    
Trading Symbol sfbs    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer Yes    
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Common Stock, Shares Outstanding (in shares)   53,475,208  
Entity Public Float     $ 1,882,356
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Shell Company false