XML 21 R73.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Fair Value Measurements (Additional Quantitative Information About Assets Measured At Fair Value On A Recurring And Non-Recurring Basis) (Details) $ in Thousands | 9 Months Ended
--- | ---
Sep. 30, 2015 USD ($)
Collateral Dependent Impaired Loans [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Assets at fair value | $ 1,579 |
Loan Servicing Rights [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Assets at fair value | $ 1,241 |
Discount rate | 4.90% | [1]
Constant prepayment rate | 12.70% | [1]
Other Real Estate Owned [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Assets at fair value | $ 286 |
Minimum [Member] | Collateral Dependent Impaired Loans [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Appraisal adjustments | 0.00% |
Minimum [Member] | Other Real Estate Owned [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Appraisal adjustments | 20.00% |
Maximum [Member] | Collateral Dependent Impaired Loans [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Appraisal adjustments | 100.00% |
Maximum [Member] | Other Real Estate Owned [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Appraisal adjustments | 70.00% |
[1] | Weighted averages.

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FairValueInputsAssetsQuantitativeInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsComparabilityAdjustments
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsPrepaymentRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fisi_CollateralDependentImpairedFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fisi_LoanServicingRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fisi_OtherRealEstateOwnedOtherReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |