XML 37 R52.htm IDEA: XBRL DOCUMENT v3.2.0.727

Loans (Commercial Loan Portfolio Categorized By Internally Assigned Asset Classification) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,978,624	$ 1,881,071
Commercial Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	292,674	267,377
Commercial Business [Member] | Uncriticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	275,639	250,961
Commercial Business [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,078	5,530
Commercial Business [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 11,957	$ 10,886
Commercial Business [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans
Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 538,034	$ 476,407
Commercial Mortgage [Member] | Uncriticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	523,226	460,880
Commercial Mortgage [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	6,015	5,411
Commercial Mortgage [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 8,793	$ 10,116
Commercial Mortgage [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans

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=fisi_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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