XML 73 R62.htm IDEA: XBRL DOCUMENT v3.22.1

REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Net gains (losses) on sales of OREO	$ 0	$ (18)
Changes in fair value of equity investments	(113)	86
Income from bank owned life insurance	11	15
Other non-interest income	5,663	5,621
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Other non-interest income	213	252
Overdraft fees
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	673	450
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	191	267
Interchange revenue from debit card transactions
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	1,130	1,123
WMG fee income
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	2,757	2,678
CFS fee and commission income
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	253	214
Net gains (losses) on sales of OREO
Disaggregation of Revenue [Line Items]
Net gains (losses) on sales of OREO	0	(18)
Net gains on sales of loans
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	74	300
Loan servicing fees
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	39	35
Income from bank-owned life insurance
Disaggregation of Revenue [Line Items]
Income from bank owned life insurance	11	15
Other
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	648	471
Core Banking | Operating Segments
Disaggregation of Revenue [Line Items]
Changes in fair value of equity investments	(114)	34
Other non-interest income	2,693	2,691
Core Banking | Overdraft fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	673	450
Core Banking | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	191	267
Core Banking | Interchange revenue from debit card transactions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	1,130	1,123
Core Banking | WMG fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Core Banking | CFS fee and commission income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Core Banking | Net gains (losses) on sales of OREO | Operating Segments
Disaggregation of Revenue [Line Items]
Net gains (losses) on sales of OREO	0	(18)
Core Banking | Net gains on sales of loans | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	74	300
Core Banking | Loan servicing fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	39	35
Core Banking | Income from bank-owned life insurance | Operating Segments
Disaggregation of Revenue [Line Items]
Income from bank owned life insurance	11	15
Core Banking | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	689	485
WMG | Operating Segments
Disaggregation of Revenue [Line Items]
Changes in fair value of equity investments	0	0
Other non-interest income	2,757	2,678
WMG | Overdraft fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
WMG | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
WMG | Interchange revenue from debit card transactions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
WMG | WMG fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	2,757	2,678
WMG | CFS fee and commission income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
WMG | Net gains (losses) on sales of OREO | Operating Segments
Disaggregation of Revenue [Line Items]
Net gains (losses) on sales of OREO	0	0
WMG | Net gains on sales of loans | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	0	0
WMG | Loan servicing fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	0	0
WMG | Income from bank-owned life insurance | Operating Segments
Disaggregation of Revenue [Line Items]
Income from bank owned life insurance	0	0
WMG | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	0	0
Holding Company, CFS, and CRM | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Changes in fair value of equity investments	1	52
Other non-interest income	213	252
Holding Company, CFS, and CRM | Overdraft fees | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Holding Company, CFS, and CRM | Other | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Holding Company, CFS, and CRM | Interchange revenue from debit card transactions | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Holding Company, CFS, and CRM | WMG fee income | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	0	0
Holding Company, CFS, and CRM | CFS fee and commission income | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenues from contracts with customer	253	214
Holding Company, CFS, and CRM | Net gains (losses) on sales of OREO | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net gains (losses) on sales of OREO	0	0
Holding Company, CFS, and CRM | Net gains on sales of loans | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	0	0
Holding Company, CFS, and CRM | Loan servicing fees | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	0	0
Holding Company, CFS, and CRM | Income from bank-owned life insurance | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Income from bank owned life insurance	0	0
Holding Company, CFS, and CRM | Other | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue not from contact with customer	$ (41)	$ (14)

X

- Definition

Earnings on or other increases in the value of the cash surrender value of bank owned life insurance policies.

+ 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 210.9-04.13)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

Name:	us-gaap_BankOwnedLifeInsuranceIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

X

- Definition

Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117546-209714

+ Details

Name:	us-gaap_EquitySecuritiesFvNiGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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 http://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

- Definition

The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

+ 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 210.9-04.13)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

Name:	us-gaap_NoninterestIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of revenue that is not accounted for under Topic 606.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

+ Details

Name:	us-gaap_RevenueNotFromContractWithCustomer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_OverdraftFeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_ServiceChargeonDepositsOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_InterchangeRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_WMGFeeIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_InvestmentBrokerageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_SaleofOREOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_SaleofLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_LoanServicingFeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_IncomeFromBankOwnedLifeInsuranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=chmg_ProductsAndServicesOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=chmg_CoreBankingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=chmg_WealthManagementGroupServicesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=chmg_HoldingCompanyCFSAndCRMMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: