XML 19 R42.htm IDEA: XBRL DOCUMENT
v2.4.0.8

ACCUMULATED OTHER COMPREHENSIVE INCOME OR LOSS (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward] |  |  |  |  |  |  |  |
Balance at beginning of period | $ 787 |  | $ (2,623) |  | $ 155 |  | $ (2,807) |
Other comprehensive income before Reclassification | 696 |  | (2) |  | 1,240 |  | (2,035) |
Amounts reclassified from accumulated other comprehensive income | (233) |  | 240 |  | (145) |  | 467 |
Net current period other comprehensive income | 463 |  | (1,752) |  | 1,095 |  | (1,568) |
Balance at end of period | 1,250 |  | (4,375) |  | 1,250 |  | (4,375) |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Net gain on securities transactions | 522 |  | 1 |  | 522 |  | 1 |
Pension and other employee benefits | 1,479 |  | 1,365 |  | 2,838 |  | 2,789 |
Income tax expense | 869 |  | 1,306 |  | 1,820 |  | 2,478 |
Net of tax | 1,930 |  | 2,655 |  | 3,994 |  | 5,066 |
Reclassification out of Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |  |  |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Net of tax | 233 |  | (239) |  | 145 |  | (466) |
Unrealized Gains and Losses on Securities Available for Sale [Member] |  |  |  |  |  |  |  |
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward] |  |  |  |  |  |  |  |
Balance at beginning of period | 6,587 |  | 7,980 |  | 6,043 |  | 8,023 |
Other comprehensive income before Reclassification | 696 |  | (1,992) |  | 1,240 |  | (2,035) |
Amounts reclassified from accumulated other comprehensive income | (321) |  | 0 |  | (321) |  | 0 |
Net current period other comprehensive income | 375 |  | (1,992) |  | 919 |  | (2,035) |
Balance at end of period | 6,962 |  | 5,988 |  | 6,962 |  | 5,988 |
Unrealized Gains and Losses on Securities Available for Sale [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |  |  |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Total impairment losses | 0 |  | 0 |  | 0 |  | 0 |
Net gain on securities transactions | 522 |  | 1 |  | 522 |  | 1 |
Income tax expense | 201 |  | 0 |  | 201 |  | 0 |
Net of tax | 321 |  | 1 |  | 321 |  | 1 |
Defined Benefit and Other Benefit Plans [Member] |  |  |  |  |  |  |  |
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward] |  |  |  |  |  |  |  |
Balance at beginning of period | (5,800) |  | (10,603) |  | (5,888) |  | (10,830) |
Other comprehensive income before Reclassification | 0 |  | 0 |  | 0 |  | 0 |
Amounts reclassified from accumulated other comprehensive income | 88 |  | 240 |  | 176 |  | 467 |
Net current period other comprehensive income | 88 |  | 240 |  | 176 |  | 467 |
Balance at end of period | (5,712) |  | (10,363) |  | (5,712) |  | (10,363) |
Defined Benefit and Other Benefit Plans [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |  |  |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Income tax expense | 55 |  | 140 |  | 110 |  | 293 |
Net of tax | (88) |  | (240) |  | (176) |  | (467) |
Prior Service Costs [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |  |  |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Pension and other employee benefits | 22 | [1] | 21 | [1] | 44 | [1] | 41 | [1]
Actuarial Losses [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |  |  |
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items] |  |  |  |  |  |  |  |
Pension and other employee benefits | $ (165) | [1] | $ (401) | [1] | $ (330) | [1] | $ (801) | [1]
[1] | These accumulated other comprehensive income components are included in the computation of net periodic pension and other benefit plan costs (see Note 9 for additional information).

X
- Definition Amount of payroll tax expense, compensation, postemployment and benefit-related expenses not elsewhere specified in the taxonomy (such as health plan, profit sharing, incentives, tuition reimbursement, other fringe benefits and perquisites) incurred in the period. + References No definition available. + Details
Name: | chmg_PensionAndOtherEmployeeBenefitExpense
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total other-than-temporary impairment ('OTTI') losses. + References No definition available. + Details
Name: | chmg_TotalOtherThanTemporaryImpairmentOiitLosses
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 + Details
Name: | us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The net gain (loss) realized from the sale, exchange, redemption, or retirement of securities, not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13(h)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 13 -Subparagraph h -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.3) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 3 -Article 7 + Details
Name: | us-gaap_GainLossOnSaleOfSecuritiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + 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.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Income Tax Expense (or Benefit) -URI http://asc.fasb.org/extlink&oid=6515339 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=6519514 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=6518256 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.19) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.18) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.22) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 20 -Article 9 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax, before reclassification adjustments of other comprehensive income (loss). + References No definition available. + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669619-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after tax of reclassification adjustments of other comprehensive income (loss). + References No definition available. + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration