Allowance for Credit Losses, Related to Troubled Debt Restructured Loans

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable Modifications Number Of Contracts Outstanding

+ References

No definition available.

+ Details

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Namespace Prefix:	cac_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- 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

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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=66008989&loc=SL6953676-111524

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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=25495931&loc=d3e18845-111554

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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- Details

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- Details

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Data Type:	na
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- Details

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LOANS AND ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring Loans) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) loan	Mar. 31, 2016 loan	Mar. 31, 2016	Dec. 31, 2016 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	36			35
Recorded Investment	$ 5,868			$ 5,747
Specific Reserve	$ 500			$ 483
Number of Contracts	1	0	0
Residential Real Estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	22			21
Recorded Investment	$ 3,354			$ 3,221
Specific Reserve	$ 485			$ 483
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	3			3
Recorded Investment	$ 1,003			$ 1,008
Specific Reserve	$ 15			$ 0
Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	10			10
Recorded Investment	$ 1,497			$ 1,502
Specific Reserve	$ 0			$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	1			1
Recorded Investment	$ 14			$ 16
Specific Reserve	$ 0			$ 0