XML 68 R1.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Jun. 30, 2019
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Entity Registrant Name AMERISERV FINANCIAL INC /PA/    
Entity Central Index Key 0000707605    
Current Fiscal Year End Date --12-31    
Entity Filer Category Non-accelerated Filer    
Entity Current Reporting Status Yes    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Interactive Data Current Yes    
Entity Common Stock, Shares Outstanding   17,057,871  
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Public Float     $ 65,717,632
Trading Symbol ASRV