XML 51 R39.htm IDEA: XBRL DOCUMENT
v3.21.1

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowances (Details) - USD ($) $ in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2021 | Dec. 31, 2020
Allowance for loan losses, by portfolio segment [Roll Forward] |  |  |  |
Beginning balance | $ 20,924 | $ 23,478 |  |
Charge-offs | (190) | (433) |  |
Recoveries | 434 | 140 |  |
Net recoveries (charge-offs) | 244 | (293) |  |
Provision | (259) | 3,050 |  |
Ending balance | 20,909 | 26,235 |  |
Ending allowance balance attributable to loans: |  |  |  |
Individually evaluated for impairment |  |  | $ 1,579 | $ 1,527
Collectively evaluated for impairment |  |  | 19,330 | 19,397
Total ending allowance balance | 20,924 | 26,235 | 20,909 | 20,924
Loans: |  |  |  |
Loans individually evaluated for impairment |  |  | 9,922 | 10,589
Loans collectively evaluated for impairment |  |  | 1,576,062 | 1,530,909
Total ending loans balance |  |  | 1,585,984 | 1,541,498
Commercial and Agricultural |  |  |  |
Allowance for loan losses, by portfolio segment [Roll Forward] |  |  |  |
Beginning balance | 4,493 | 10,227 |  |
Charge-offs | 0 | (30) |  |
Recoveries | 296 | 4 |  |
Net recoveries (charge-offs) | 296 | (26) |  |
Provision | (452) | 990 |  |
Ending balance | 4,337 | 11,191 |  |
Ending allowance balance attributable to loans: |  |  |  |
Individually evaluated for impairment |  |  | 1,430 | 1,401
Collectively evaluated for impairment |  |  | 2,907 | 3,092
Total ending allowance balance | 4,337 | 11,191 | 4,337 | 4,493
Loans: |  |  |  |
Loans individually evaluated for impairment |  |  | 3,378 | 3,400
Loans collectively evaluated for impairment |  |  | 397,341 | 366,852
Total ending loans balance |  |  | 400,719 | 370,252
Commercial mortgages: |  |  |  |
Allowance for loan losses, by portfolio segment [Roll Forward] |  |  |  |
Beginning balance | 11,496 | 8,869 |  |
Charge-offs | 0 | 0 |  |
Recoveries | 0 | 1 |  |
Net recoveries (charge-offs) | 0 | 1 |  |
Provision | 290 | 1,603 |  |
Ending balance | 11,786 | 10,473 |  |
Ending allowance balance attributable to loans: |  |  |  |
Individually evaluated for impairment |  |  | 107 | 74
Collectively evaluated for impairment |  |  | 11,679 | 11,422
Total ending allowance balance | 11,496 | 10,473 | 11,786 | 11,496
Loans: |  |  |  |
Loans individually evaluated for impairment |  |  | 5,223 | 5,117
Loans collectively evaluated for impairment |  |  | 726,215 | 714,028
Total ending loans balance |  |  | 731,438 | 719,145
Residential mortgages |  |  |  |
Allowance for loan losses, by portfolio segment [Roll Forward] |  |  |  |
Beginning balance | 2,079 | 1,252 |  |
Charge-offs | (26) | 0 |  |
Recoveries | 0 | 0 |  |
Net recoveries (charge-offs) | (26) | 0 |  |
Provision | 62 | 169 |  |
Ending balance | 2,115 | 1,421 |  |
Ending allowance balance attributable to loans: |  |  |  |
Individually evaluated for impairment |  |  | 0 | 0
Collectively evaluated for impairment |  |  | 2,115 | 2,079
Total ending allowance balance | 2,079 | 1,421 | 2,115 | 2,079
Loans: |  |  |  |
Loans individually evaluated for impairment |  |  | 964 | 1,271
Loans collectively evaluated for impairment |  |  | 244,879 | 238,742
Total ending loans balance |  |  | 245,843 | 240,013
Consumer loans: |  |  |  |
Allowance for loan losses, by portfolio segment [Roll Forward] |  |  |  |
Beginning balance | 2,856 | 3,130 |  |
Charge-offs | (164) | (403) |  |
Recoveries | 138 | 135 |  |
Net recoveries (charge-offs) | (26) | (268) |  |
Provision | (159) | 288 |  |
Ending balance | 2,671 | 3,150 |  |
Ending allowance balance attributable to loans: |  |  |  |
Individually evaluated for impairment |  |  | 42 | 52
Collectively evaluated for impairment |  |  | 2,629 | 2,804
Total ending allowance balance | $ 2,671 | $ 3,150 | 2,671 | 2,856
Loans: |  |  |  |
Loans individually evaluated for impairment |  |  | 357 | 801
Loans collectively evaluated for impairment |  |  | 207,627 | 211,287
Total ending loans balance |  |  | $ 207,984 | $ 212,088

X
- Definition Financing Receivable, after Interest Receivable on Loans, before Allowance on Credit Loss + References No definition available. + Details
Name: | chmg_FinancingReceivableAfterInterestReceivableOnLoansBeforeAllowanceOnCreditLoss
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount of recovery of (write-downs of) financing receivables doubtful of collection. + References No definition available. + Details
Name: | chmg_FinancingReceivableAllowanceForCreditLossesNetChargeOff
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

X
- Definition Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118955202&loc=SL82895884-210446 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 Reference 4: 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(7)(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of recovery of financing receivables doubtful of collection that were previously charged off. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=118955255&loc=SL82922352-210448 Reference 2: 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(7)(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of writeoff of financing receivable, charged against allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=118955255&loc=SL82922352-210448 Reference 4: 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(7)(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The balance of financing receivables that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 + Details
Name: | us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
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: |