Allowance for Loan Losses Financing Receivable and Allowance Element by Class (Details) (USD $)	Sep. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 12,457,000	$ 12,670,000	$ 12,500,000	$ 14,739,000	$ 14,384,000	$ 13,000,000
Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,845,000		3,539,000	5,062,000
General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	4,234,000		4,304,000	4,349,000
Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	3,834,000		3,815,000	3,568,000
Unallocated Reserves [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,544,000		842,000	1,760,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	5,803,000	5,811,000	5,865,000	5,695,000	5,564,000	5,659,000
Commercial Real Estate Portfolio Segment [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,535,000		1,523,000	1,416,000
Commercial Real Estate Portfolio Segment [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,231,000		2,369,000	2,479,000
Commercial Real Estate Portfolio Segment [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,037,000		1,973,000	1,800,000
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	609,000	591,000	1,359,000	1,059,000	1,373,000	658,000
Commercial Construction [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	269,000		969,000	696,000
Commercial Construction [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	178,000		213,000	210,000
Commercial Construction [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	162,000		177,000	153,000
Commercial Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,269,000	2,572,000	2,050,000	2,632,000	2,476,000	2,063,000
Commercial Other [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	807,000		652,000	1,240,000
Commercial Other [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	764,000		763,000	807,000
Commercial Other [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	698,000		635,000	585,000
Municipal [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	16,000	18,000	18,000	18,000	19,000	19,000
Municipal [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses			0	0
Municipal [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses			0	0
Municipal [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	16,000		18,000	18,000
Residential Term [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	982,000	1,026,000	1,109,000	2,223,000	1,587,000	1,159,000
Residential Term [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	228,000		395,000	1,494,000
Residential Term [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	360,000		278,000	293,000
Residential Term [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	394,000		436,000	436,000
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	15,000	9,000	11,000	14,000	58,000	255,000
Residential Construction [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0		0	0
Residential Construction [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	7,000		4,000	5,000
Residential Construction [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	8,000		7,000	9,000
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	666,000	737,000	654,000	790,000	809,000	595,000
Home Equity [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	6,000		0	215,000
Home Equity [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	352,000		315,000	238,000
Home Equity [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	308,000		339,000	337,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	553,000	631,000	592,000	548,000	603,000	584,000
Consumer Portfolio Segment [Member] \| Specific Reserves Evaluated Individually for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0		0	1,000
Consumer Portfolio Segment [Member] \| General Reserves Based on Historical Loss Experience [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	342,000		362,000	317,000
Consumer Portfolio Segment [Member] \| Reserve for Qualitative Factors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	211,000		230,000	230,000
Unallocated Financing Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,544,000	1,275,000	842,000	1,760,000	1,895,000	2,008,000
Unallocated Financing Receivables [Member] \| Unallocated Reserves [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 1,544,000		$ 842,000	$ 1,760,000

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details