XML 82 R69.htm IDEA: XBRL DOCUMENT v3.7.0.1

Loans (Retail Loan Portfolio Categorized By Payment Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 2,305,071	$ 2,052,600
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	421,476	376,023
Residential Real Estate Loans [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	420,240	374,175
Residential Real Estate Loans [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,236	1,848
Residential Real Estate Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	119,745	124,766
Residential Real Estate Lines [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	119,373	124,531
Residential Real Estate Lines [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	372	235
Consumer Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	725,754	652,494
Consumer Indirect [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	724,228	651,027
Consumer Indirect [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,526	1,467
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,465	18,361
Other Consumer [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,449	18,340
Other Consumer [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 16	$ 21

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fisi_ConsumerIndirectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: