v3.22.4
Document And Entity Information
Jan. 30, 2023
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jan. 30, 2023
Entity Registrant Name Financial Institutions, Inc.
Entity Central Index Key 0000862831
Entity Emerging Growth Company false
Securities Act File Number 0-26481
Entity Incorporation, State or Country Code NY
Entity Tax Identification Number 16-0816610
Entity Address, Address Line One 220 Liberty Street
Entity Address, City or Town Warsaw
Entity Address, State or Province NY
Entity Address, Postal Zip Code 14569
City Area Code 585
Local Phone Number 786-1100
Entity Information, Former Legal or Registered Name Not Applicable
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common stock, par value $0.01 per share
Trading Symbol FISI
Security Exchange Name NASDAQ