Premises and Equipment (Equipment) (Details) (USD $)	12 Months Ended
Dec. 31, 2014 property	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 52,980,000us-gaap_PropertyPlantAndEquipmentGross	$ 52,583,000us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation and amortization	(29,094,000)	(26,856,000)
Premises and equipment, net	23,886,000us-gaap_PropertyPlantAndEquipmentNet	25,727,000us-gaap_PropertyPlantAndEquipmentNet
Gain (Loss) on Disposition of Property Plant Equipment	0	0	479,000
Number of properties	1cac_Numberofproperties
Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation, Depletion and Amortization	2,700,000	2,700,000	2,200,000
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,046,000	3,019,000
Buildings and leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	29,984,000	29,772,000
Furniture, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	19,950,000	19,792,000
Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	(3,000,000)	(2,700,000)
Depreciation, Depletion and Amortization	335,000	296,000	301,000
Capitalized Computer Software, Gross	$ 3,600,000	$ 3,200,000

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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- Definition

Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a)

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ 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=31042434&loc=d3e3602-108585

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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

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-Name Accounting Standards Codification

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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