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v2.4.1.9

RELATED PARTY TRANSACTIONS (Details) (USD $) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013
Loans to Related Parties [Roll Forward] |  |
Balance at beginning of year | $ 26,408,000 us-gaap_NotesReceivableRelatedParties | $ 25,390,000 us-gaap_NotesReceivableRelatedParties
New loans or additional advances | 33,282,000 us-gaap_LoansAndLeasesReceivableRelatedPartiesAdditions | 30,056,000 us-gaap_LoansAndLeasesReceivableRelatedPartiesAdditions
Repayments | (21,888,000)us-gaap_LoansAndLeasesReceivableRelatedPartiesCollections | (29,038,000)us-gaap_LoansAndLeasesReceivableRelatedPartiesCollections
Balance at end of year | 37,802,000 us-gaap_NotesReceivableRelatedParties | 26,408,000 us-gaap_NotesReceivableRelatedParties
Deposit Liabilities | $ 12,000,000 us-gaap_RelatedPartyDepositLiabilities | $ 9,800,000 us-gaap_RelatedPartyDepositLiabilities
Minimum [Member] |  |
Related Party Transactions [Line Items] |  |
Related party principal ownership threshold (in hundredths) | 10.00%chmg_RelatedPartyPrincipalOwnershipThreshold / us-gaap_RangeAxis = us-gaap_MinimumMember |

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- Definition For a designation as a related party, the threshold percentage of principal ownership in an entity, above which the party is considered a related party.. + References No definition available. + Details
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- Definition Reflects the amount of new advances made to related parties in the form of loan and lease receivables. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(e)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph e -Article 9 + Details
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Period Type: | duration

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- Definition Reflects the amount of collections received from related parties to reduce the carrying amounts of loans and leases receivable due from them. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(e)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph e -Article 9 + Details
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- Details
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- Definition For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.3) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Related Parties -URI http://asc.fasb.org/extlink&oid=16382449 + Details
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- Definition Amount of deposits held by the entity for a related party (entity, shareholder, employee). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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- Details
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