<SEC-DOCUMENT>0001564590-20-041209-index.html : 20200825
<SEC-HEADER>0001564590-20-041209.hdr.sgml : 20200825
<ACCEPTANCE-DATETIME>20200825165940
ACCESSION NUMBER:		0001564590-20-041209
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		14
CONFORMED PERIOD OF REPORT:	20200825
ITEM INFORMATION:		Regulation FD Disclosure
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20200825
DATE AS OF CHANGE:		20200825

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FINANCIAL INSTITUTIONS INC
		CENTRAL INDEX KEY:			0000862831
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				160816610
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26481
		FILM NUMBER:		201133014

	BUSINESS ADDRESS:	
		STREET 1:		220 LIBERTY STREET
		CITY:			WARSAW
		STATE:			NY
		ZIP:			14569
		BUSINESS PHONE:		5857861100

	MAIL ADDRESS:	
		STREET 1:		220 LIBERTY STREET
		CITY:			WARSAW
		STATE:			NY
		ZIP:			14569
</SEC-HEADER>
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<TYPE>8-K
<SEQUENCE>1
<FILENAME>fisi-8k_20200825.htm
<DESCRIPTION>8-K
<TEXT>
Document 1 - file: fisi-8k_20200825.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>fisi-ex991_6.htm
<DESCRIPTION>EX-99.1
<TEXT>
Document 2 - file: fisi-ex991_6.htm

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<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>guiissrzumw2000001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: guiissrzumw2000001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-101.SCH
<SEQUENCE>4
<FILENAME>fisi-20200825.xsd
<DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
<TEXT>
Document 4 - file: fisi-20200825.xsd

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-101.LAB
<SEQUENCE>5
<FILENAME>fisi-20200825_lab.xml
<DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE
<TEXT>
Document 5 - file: fisi-20200825_lab.xml

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<DOCUMENT>
<TYPE>EX-101.PRE
<SEQUENCE>6
<FILENAME>fisi-20200825_pre.xml
<DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE
<TEXT>
Document 6 - file: fisi-20200825_pre.xml

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<TYPE>XML
<SEQUENCE>7
<FILENAME>fisi-8k_20200825_htm.xml
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 7 - file: fisi-8k_20200825_htm.html

Document 7 - RAW XML: fisi-8k_20200825_htm.xml

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<DOCUMENT>
<TYPE>XML
<SEQUENCE>8
<FILENAME>R1.htm
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<TEXT>
Document 8 - file: R1.htm

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<DOCUMENT>
<TYPE>EXCEL
<SEQUENCE>9
<FILENAME>Financial_Report.xlsx
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 9 - file: Financial_Report.xlsx

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>10
<FILENAME>Show.js
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 10 - file: Show.js

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<DOCUMENT>
<TYPE>XML
<SEQUENCE>11
<FILENAME>report.css
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<TEXT>
Document 11 - file: report.css

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<DOCUMENT>
<TYPE>XML
<SEQUENCE>12
<FILENAME>FilingSummary.xml
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<TEXT>
Document 12 - file: FilingSummary.html

Document 12 - RAW XML: FilingSummary.xml

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<DOCUMENT>
<TYPE>JSON
<SEQUENCE>15
<FILENAME>MetaLinks.json
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 15 - file: MetaLinks.json

</DOCUMENT>
<DOCUMENT>
<TYPE>ZIP
<SEQUENCE>16
<FILENAME>0001564590-20-041209-xbrl.zip
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 16 - file: 0001564590-20-041209-xbrl.zip

</DOCUMENT>
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