XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.7.0.1

LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2017 USD ($) loan | Mar. 31, 2017 USD ($) loan | Jun. 30, 2016 USD ($) loan | Mar. 31, 2016 USD ($) loan | Jun. 30, 2017 USD ($) loan | Jun. 30, 2016 USD ($) loan | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | $ 25,691,000 |  |  |  | $ 25,691,000 |  | $ 20,713,000 |
Other industry exposures |  |  |  |  | 0 |  |  |
Interest lost on nonaccrual loans | $ 277,000 |  | $ 240,000 |  | $ 486,000 | $ 424,000 |  |
Number of TDRs | loan | 1 |  | 0 | 0 | 2 | 0 |  |
Commitments to lend |  |  |  |  |  |  | 0 |
Loans modified | loan |  | 0 |  | 0 | 0 | 0 |  |
Financing Receivable, Individually Evaluated for Impairment | $ 20,080,000 |  | $ 11,237,000 |  | $ 20,080,000 | $ 11,237,000 |  |
Proceeds from the sale of mortgage loans |  |  |  |  | 93,557,000 | 97,375,000 |  |
Gain on sale of mortgage loans |  |  |  |  | 2,656,000 | 2,166,000 |  |
Loans held for sale, at fair value | 10,784,000 |  |  |  | 10,784,000 |  | 14,836,000 |
Financing Receivable, Allowance for Credit Losses | 24,394,000 | $ 23,721,000 | 23,717,000 | $ 21,339,000 | 24,394,000 | 23,717,000 | 23,116,000 | $ 21,166,000
FHLB advances, general debt obligations, pledged collateral | 1,100,000,000 |  |  |  | 1,100,000,000 |  | 1,100,000,000 |
Derivative, Fair Value, Net | 297,000 |  |  |  | 297,000 |  | 278,000 |
Unrealized Gain (Loss) on Derivatives | 235,000 |  | 92,000 |  | 223,000 | 384,000 |  |
Loans |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Loans restructured due to credit difficulties that are now performing | 4,800,000 |  |  |  | 4,800,000 |  | 4,300,000 |
Financing receivables impaired TDR non-performing | 1,300,000 |  |  |  | 1,300,000 |  | 1,400,000 |
Residential Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 4,890,000 |  |  |  | 4,890,000 |  | 3,945,000 |
Financing Receivable, Individually Evaluated for Impairment | 4,451,000 |  | 4,926,000 |  | 4,451,000 | 4,926,000 | 4,348,000 |
Mortgage Loans in Process of Foreclosure, Amount | 2,100,000 |  |  |  | 2,100,000 |  | 1,400,000 |
Financing Receivable, Allowance for Credit Losses | 4,481,000 | 4,271,000 | 4,431,000 | 4,516,000 | 4,481,000 | 4,431,000 | 4,160,000 | 4,545,000
Commercial Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 16,291,000 |  |  |  | 16,291,000 |  | 12,849,000 |
Financing Receivable, Individually Evaluated for Impairment | 13,116,000 |  | 2,340,000 |  | 13,116,000 | 2,340,000 | 13,317,000 |
Financing Receivable, Allowance for Credit Losses | 12,848,000 | 12,726,000 | 11,559,000 | 10,380,000 | 12,848,000 | 11,559,000 | 12,154,000 | 10,432,000
Commercial |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 2,056,000 |  |  |  | 2,056,000 |  | 2,088,000 |
Financing Receivable, Individually Evaluated for Impairment | 2,067,000 |  | 3,461,000 |  | 2,067,000 | 3,461,000 | 2,028,000 |
Financing Receivable, Allowance for Credit Losses | 4,275,000 | 3,815,000 | 4,558,000 | 3,298,000 | 4,275,000 | 4,558,000 | 3,755,000 | 3,241,000
Home Equity |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 1,371,000 |  |  |  | 1,371,000 |  | 1,620,000 |
Financing Receivable, Individually Evaluated for Impairment | 446,000 |  | 503,000 |  | 446,000 | 503,000 | 457,000 |
Financing Receivable, Allowance for Credit Losses | 2,094,000 | 2,107,000 | 2,946,000 | 2,622,000 | 2,094,000 | 2,946,000 | 2,194,000 | 2,731,000
Consumer |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 0 |  |  |  | 0 |  | 4,000 |
Financing Receivable, Individually Evaluated for Impairment | 0 |  | 7,000 |  | 0 | 7,000 | 7,000 |
Financing Receivable, Allowance for Credit Losses | 182,000 | 175,000 | 193,000 | 182,000 | 182,000 | 193,000 | 181,000 | 193,000
HPFC Portfolio Segment |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Non-Accrual Loans | 1,083,000 |  |  |  | 1,083,000 |  | 207,000 |
Financing Receivable, Individually Evaluated for Impairment | 0 |  | 0 |  | 0 | 0 | 97,000 |
Financing Receivable, Allowance for Credit Losses | 514,000 | $ 627,000 | 30,000 | $ 341,000 | 514,000 | 30,000 | 672,000 | 24,000
Unallocated |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  |  |  | 20,254,000 |
Financing Receivable, Allowance for Credit Losses |  |  |  |  |  |  | 23,116,000 | $ 21,166,000
Fixed Rate Residential Mortgage |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Proceeds from the sale of mortgage loans | 47,900,000 |  | 56,300,000 |  | 90,900,000 | 95,200,000 |  |
Gain on sale of mortgage loans | 1,400,000 |  | 1,300,000 |  | 2,700,000 | 2,200,000 |  |
Loans held for sale, at fair value | 10,900,000 |  |  |  | 10,900,000 |  | 15,100,000 |
Nonoperating Income (Expense) | Fixed Rate Residential Mortgage |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Gain on sale of mortgage loans | $ (63,000) |  | 147,000 |  | 191,000 | 153,000 |  |
Unrealized gain (loss) on loans held for sale |  |  |  |  | $ 98,000 | 289,000 |  |
Minimum |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  |  |  | 250,000 |
Number of Months | 18 |  |  |  | 18 |  |  |
Minimum | HPFC Portfolio Segment |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Term to maturity | 7 years |  |  |  |  |  |  |
Maximum |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Number of Months | 24 |  |  |  | 24 |  |  |
Maximum | HPFC Portfolio Segment |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Term to maturity | 10 years |  |  |  |  |  |  |
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Total Loan Portfolio |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Concentration risk (percentage) |  |  |  |  | 12.00% |  |  |
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Commercial Real Estate |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Concentration risk (percentage) |  |  |  |  | 28.00% |  |  |
Substandard (Grade 8) | Minimum |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Financing Receivable, Individually Evaluated for Impairment | $ 500,000 |  |  |  | $ 500,000 |  |  |
Forward Contracts [Member] |  |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |  |
Derivative, Fair Value, Net | 297,000 |  |  |  | 297,000 |  | $ 278,000 |
Unrealized Gain (Loss) on Derivatives | $ 137,000 |  | $ 0 |  | $ 19,000 | $ 0 |  |

X
- Definition Financing Receivables Impaired Troubled Debt Restructuring Non-Performing + References No definition available. + Details
Name: | cac_FinancingReceivablesImpairedTroubledDebtRestructuringNonPerforming
Namespace Prefix: | cac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivables, Impaired, Troubled Debt Restructuring, Performing + References No definition available. + Details
Name: | cac_FinancingReceivablesImpairedTroubledDebtRestructuringPerforming
Namespace Prefix: | cac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of months to resolve foreclosure + References No definition available. + Details
Name: | cac_NumberofMonths
Namespace Prefix: | cac_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Portfolio Concentration Industries + References No definition available. + Details
Name: | cac_NumberofPortfolioConcentrationIndustries
Namespace Prefix: | cac_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition term to maturity + References No definition available. + Details
Name: | cac_Termtomaturity
Namespace Prefix: | cac_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrealized gain (loss) on loans held for sale + References No definition available. + Details
Name: | cac_Unrealizedgainlossonloansheldforsale
Namespace Prefix: | cac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13495-108611 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the collateral pledged in support of federal home loan bank advances outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition A valuation allowance for financing receivables that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The balance of financing receivables that were individually evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Recorded Investment -URI http://asc.fasb.org/extlink&oid=65880944 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnSaleOfMortgageLoans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The face amount of loans that will be sold to other entities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522 + Details
Name: | us-gaap_LoansReceivableHeldForSaleAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL49126937-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Recorded Investment -URI http://asc.fasb.org/extlink&oid=65880944 + Details
Name: | us-gaap_MortgageLoansInProcessOfForeclosureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3536-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 21 -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3461-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

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

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_FixedRateResidentialMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_NonoperatingIncomeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=cac_NonResidentialBuildingOperatorsIndustrySectorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=cac_LoanConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=cac_TotalLoanPortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |