XML 58 R47.htm IDEA: XBRL DOCUMENT
v3.22.2

FAIR VALUE - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021 | Dec. 31, 2021
Financial Assets: |  |  |  |  |
Total | $ 692,995 |  | $ 692,995 |  | $ 792,026
Other real estate owned: |  |  |  |  |
Net gains (losses) on sales of OREO | 46 | $ 0 | 46 | $ (18) |
Recurring |  |  |  |  |
Financial Assets: |  |  |  |  |
U.S. Treasury notes and bonds | 56,304 |  | 56,304 |  | 60,431
Mortgage-backed securities, residential | 483,276 |  | 483,276 |  | 577,361
Obligations of states and political subdivisions | 38,966 |  | 38,966 |  | 42,303
Corporate bonds and notes | 24,933 |  | 24,933 |  | 22,848
SBA loan pools | 89,516 |  | 89,516 |  | 89,083
Total | 692,995 |  | 692,995 |  | 792,026
Equity investments, at fair value | 2,190 |  | 2,190 |  | 2,404
Derivative assets | 17,616 |  | 17,616 |  | 9,498
Financial Liabilities: |  |  |  |  |
Derivative Liabilities | 17,673 |  | 17,673 |  | 9,726
Non-recurring | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 137 |  | 137 |  | 143
Net gains (losses) on sales of OREO |  |  | 0 |  | 0
Non-recurring | Residential Mortgages | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 83 |  | 83 |  | 143
Net gains (losses) on sales of OREO |  |  | 0 |  | 0
Non-recurring | Consumer Loans | Other real estate owned: | Home equity lines and loans |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 54 |  | 54 |  |
Net gains (losses) on sales of OREO |  |  | 0 |  |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring |  |  |  |  |
Financial Assets: |  |  |  |  |
U.S. Treasury notes and bonds | 56,304 |  | 56,304 |  | 60,431
Mortgage-backed securities, residential | 0 |  | 0 |  | 0
Obligations of states and political subdivisions | 0 |  | 0 |  | 0
Corporate bonds and notes | 0 |  | 0 |  | 0
SBA loan pools | 0 |  | 0 |  | 0
Total | 56,304 |  | 56,304 |  | 60,431
Equity investments, at fair value | 2,190 |  | 2,190 |  | 2,404
Derivative assets | 0 |  | 0 |  | 0
Financial Liabilities: |  |  |  |  |
Derivative Liabilities | 0 |  | 0 |  | 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-recurring | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  | 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-recurring | Residential Mortgages | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  | 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-recurring | Consumer Loans | Other real estate owned: | Home equity lines and loans |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  |
Significant Other Observable Inputs (Level 2) | Recurring |  |  |  |  |
Financial Assets: |  |  |  |  |
U.S. Treasury notes and bonds | 0 |  | 0 |  | 0
Mortgage-backed securities, residential | 483,276 |  | 483,276 |  | 577,361
Obligations of states and political subdivisions | 38,966 |  | 38,966 |  | 42,303
Corporate bonds and notes | 24,933 |  | 24,933 |  | 22,848
SBA loan pools | 89,516 |  | 89,516 |  | 89,083
Total | 636,691 |  | 636,691 |  | 731,595
Equity investments, at fair value | 0 |  | 0 |  | 0
Derivative assets | 17,616 |  | 17,616 |  | 9,498
Financial Liabilities: |  |  |  |  |
Derivative Liabilities | 17,673 |  | 17,673 |  | 9,726
Significant Other Observable Inputs (Level 2) | Non-recurring | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  | 0
Significant Other Observable Inputs (Level 2) | Non-recurring | Residential Mortgages | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  | 0
Significant Other Observable Inputs (Level 2) | Non-recurring | Consumer Loans | Other real estate owned: | Home equity lines and loans |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 0 |  | 0 |  |
Significant Unobservable Inputs (Level 3) | Recurring |  |  |  |  |
Financial Assets: |  |  |  |  |
U.S. Treasury notes and bonds | 0 |  | 0 |  | 0
Mortgage-backed securities, residential | 0 |  | 0 |  | 0
Obligations of states and political subdivisions | 0 |  | 0 |  | 0
Corporate bonds and notes | 0 |  | 0 |  | 0
SBA loan pools | 0 |  | 0 |  | 0
Total | 0 |  | 0 |  | 0
Equity investments, at fair value | 0 |  | 0 |  | 0
Derivative assets | 0 |  | 0 |  | 0
Financial Liabilities: |  |  |  |  |
Derivative Liabilities | 0 |  | 0 |  | 0
Significant Unobservable Inputs (Level 3) | Non-recurring | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 137 |  | 137 |  | 143
Significant Unobservable Inputs (Level 3) | Non-recurring | Residential Mortgages | Other real estate owned: |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | 83 |  | 83 |  | $ 143
Significant Unobservable Inputs (Level 3) | Non-recurring | Consumer Loans | Other real estate owned: | Home equity lines and loans |  |  |  |  |
Other real estate owned: |  |  |  |  |
Total other real estate owned, net | $ 54 |  | $ 54 |  |

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents corporate bonds and notes as of the balance sheet date which have been categorized as available-for-sale. + References No definition available. + Details
Name: | chmg_CorporateBondsAndNotesFairValueDisclosure
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents obligations of states and political subdivisions as of the balance sheet date which have been categorized as available-for-sale. + References No definition available. + Details
Name: | chmg_ObligationsOfStatesAndPoliticalSubdivisionsFairValueDisclosure
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents small business administration pool loans as of the balance sheet date which have been categorized as available-for-sale. + References No definition available. + Details
Name: | chmg_SmallBusinessAdministrationPoolLoansFairValueDisclosure
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition US Treasury Notes and Bonds Fair Value Disclosure + References No definition available. + Details
Name: | chmg_USTreasuryNotesAndBondsFairValueDisclosure
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 22 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 22 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14(d)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_GainsLossesOnSalesOfOtherRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(4)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 + Details
Name: | us-gaap_OtherRealEstateAndForeclosedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_OtherRealEstateAndForeclosedAssetsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.4) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_TradingSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |