Securities Available For Sale (Narrative) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) security shares	Dec. 31, 2015 USD ($)
Schedule of Available for sale Securities [Line Items]
Unrealized losses on securities	$ 8,896	$ 3,041
US Government-Sponsored Enterprises [Member]
Schedule of Available for sale Securities [Line Items]
Unrealized losses on securities	$ 4,865	$ 2,155
Aggregate unrealized losses represented by percentage of securities in unrealized loss positions	1.50%	0.70%
US Government Agencies [Member]
Schedule of Available for sale Securities [Line Items]
Unrealized losses on securities	$ 613	$ 547
Aggregate unrealized losses represented by percentage of securities in unrealized loss positions	0.80%	0.70%
Private Label [Member]
Schedule of Available for sale Securities [Line Items]
Number of private label MBS securities held \| security	4
Unrealized gain, net of tax	$ 130	$ 462
Unrealized losses on securities	$ 11	$ 11
Aggregate unrealized losses represented by percentage of securities in unrealized loss positions	1.20%	0.40%
Obligations Of States And Political Subdivisions Thereof [Member]
Schedule of Available for sale Securities [Line Items]
Unrealized losses on securities	$ 3,407	$ 328
Aggregate unrealized losses represented by percentage of securities in unrealized loss positions	2.80%	0.30%
Accumulated Other-than-Temporary Impairment Attributable to Parent [Member] \| Private Label [Member]
Schedule of Available for sale Securities [Line Items]
Amortized cost included OTTI losses	$ 42
Bar Harbor Bank & Trust [Member] \| Visa Class B [Member]
Schedule of Available for sale Securities [Line Items]
Number of Visa Class shares owned \| shares	11,623
Bar Harbor Bank & Trust [Member] \| Visa Class A [Member]
Schedule of Available for sale Securities [Line Items]
Number of Visa Class shares owned \| shares	19,158
Conversion ratio, Visa Class	1.648

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Investment Owned Shares Conversion Ratio

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Number Of Private Label MBS Securities Held

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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The change in unrealized holding gain (loss), net of tax, on available-for-sale securities included in a separate component of shareholders' equity during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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- Definition

Balance held at close of period in number of shares.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
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The amount of other than temporary impairment losses on investments in debt securities categorized as Held-to-maturity which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) of investments in debt securities due to credit losses and other than temporary impairments due to other than credit losses when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

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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.

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