XML 76 R63.htm IDEA: XBRL DOCUMENT v3.8.0.1

Loans Held For Sale And Loan Servicing Rights (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans Held For Sale And Loan Servicing Rights [Abstract]
Loans held for sale	$ 2,718	$ 1,050
Residential real estate mortgages serviced for others	163,300	173,700
Escrow and other custodial funds	$ 3,700	$ 4,000

X

- Definition

Loans Held For Sale And Loan Servicing Rights [Abstract]

+ References

No definition available.

+ Details

Name:	fisi_LoansHeldForSaleAndLoanServicingRightsAbstract
Namespace Prefix:	fisi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Residential Real Estate Mortgages Serviced For Others

+ References

No definition available.

+ Details

Name:	fisi_ResidentialRealEstateMortgagesServicedForOthers
Namespace Prefix:	fisi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

X

- Definition

Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

+ 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=82891408&loc=d3e4428-111522

+ Details

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