Allowance for Credit Losses, Related to Troubled Debt Restructured Loans

No definition available.

Name:	cac_AllowanceForCreditLossesRelatedToTroubledDebtRestructuredLoans
Namespace Prefix:	cac_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Gross commercial loans acquired in business acquisition.

+ References

No definition available.

+ Details

Name:	cac_BusinessAcquisitionCommercialLoansAcquiredGross
Namespace Prefix:	cac_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value mark recognized on commercial loans acquired in business acquisition.

+ References

No definition available.

+ Details

Name:	cac_BusinessAcquisitionFairValueMarkRecognizedOnCommercialLoansAcquired
Namespace Prefix:	cac_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lodging loans expressed as a percentage of the total commercial real estate loans.

+ References

No definition available.

+ Details

Name:	cac_CreditConcentrationRiskOfLodgingLoansExpressedAsPercentageOfTotalCommercialRealEstateLoans
Namespace Prefix:	cac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Non-residential building operator loans expressed as a percentage of the total commercial real estate loans.

+ References

No definition available.

+ Details

Name:	cac_CreditConcentrationRiskOfNonresidentialBuildingOperatorLoansExpressedAsPercentageOfTotalCommercialRealEstateLoans
Namespace Prefix:	cac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

- Details

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

- 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=7512638&loc=SL6953676-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of the outstanding recorded investment related to 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 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6951948&loc=d3e18845-111554

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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 Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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=6943989&loc=d3e3602-108585

+ Details

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

- Definition

The carrying amount of mortgage loans on real estate that were sold during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.6)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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

LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) (USD $)	6 Months Ended			3 Months Ended
	Jun. 30, 2013 loans	Jun. 30, 2012	Dec. 31, 2012 loans	Jun. 30, 2013 Fixed Rate Residential Mortgage	Jun. 30, 2012 Fixed Rate Residential Mortgage	Jun. 30, 2013 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans sold on secondary market				$ 19,800,000	$ 18,800,000
Gain (loss) on sale of mortgage loans	652,000	268,000		652,000,000	268,000,000
Gross performing commercial loans acquired in business acquisition			6,000,000
Fair value mark recognized on commercial loans acquired in business acquisition			317,000,000
Non-residential building operator loans expressed as a percentage of the total commercial real estate loans	29.00%
Lodging loans expressed as a percentage of the total commercial real estate loans	23.00%
Allowance for credit Losses related to troubled debt restructuring	552,000,000		494,000,000
Number of Contracts	38		30			7
Current Balance	6,667,000		5,868,000			872,000,000
Loans restructured due to credit difficulties that are now performing	$ 5,700,000		$ 4,700,000