Imparied Loan Information by Portfolio (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Impaired loans by loan portfolio
Related Allowance	$ 2,416	$ 3,774	$ 3,420
Recorded Investment	58,035	72,055	66,659
Unpaid Principal Balance	61,887	75,817	70,649
Average Recorded Investment	62,202	76,523	70,595
Interest Income Recognized	3,242	3,968	4,011
With No Related Allowance Recorded [Member]
Impaired loans by loan portfolio
Recorded Investment	26,936	29,685	27,297
Unpaid Principal Balance	28,535	32,186	29,689
Average Recorded Investment	29,464	32,896	29,831
Interest Income Recognized	1,665	1,915	1,808
With No Related Allowance Recorded [Member] \| Commercial and Industrial [Member]
Impaired loans by loan portfolio
Recorded Investment	3,005	7,147	5,849
Unpaid Principal Balance	3,278	7,288	7,343
Average Recorded Investment	4,557	7,338	6,993
Interest Income Recognized	258	338	391
With No Related Allowance Recorded [Member] \| Commercial Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	15,982	14,283	12,999
Unpaid Principal Balance	17,164	15,891	13,698
Average Recorded Investment	16,703	15,728	13,984
Interest Income Recognized	1,025	1,075	952
With No Related Allowance Recorded [Member] \| Commercial Construction [Member]
Impaired loans by loan portfolio
Recorded Investment	311	100
Unpaid Principal Balance	311	408
Average Recorded Investment	311	1,105
Interest Income Recognized	13	43
With No Related Allowance Recorded [Member] \| Small Business [Member]
Impaired loans by loan portfolio
Recorded Investment	692	1,474	1,085
Unpaid Principal Balance	718	1,805	1,147
Average Recorded Investment	772	1,854	1,217
Interest Income Recognized	45	121	80
With No Related Allowance Recorded [Member] \| Residential Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	2,439	1,972	2,545
Unpaid Principal Balance	2,502	2,026	2,630
Average Recorded Investment	2,493	2,021	2,589
Interest Income Recognized	102	95	118
With No Related Allowance Recorded [Member] \| Home Equity [Member]
Impaired loans by loan portfolio
Recorded Investment	4,169	4,263	4,119
Unpaid Principal Balance	4,221	4,322	4,166
Average Recorded Investment	4,264	4,335	4,190
Interest Income Recognized	198	202	195
With No Related Allowance Recorded [Member] \| Consumer - Other [Member]
Impaired loans by loan portfolio
Recorded Investment	338	446	700
Unpaid Principal Balance	341	446	705
Average Recorded Investment	364	515	858
Interest Income Recognized	24	41	72
With Allowance Recorded [Member]
Impaired loans by loan portfolio
Recorded Investment	31,099	42,370	39,362
Unpaid Principal Balance	33,352	43,631	40,960
Related Allowance	2,416	3,774	3,420
Average Recorded Investment	32,738	43,627	40,764
Interest Income Recognized	1,577	2,053	2,203
With Allowance Recorded [Member] \| Commercial and Industrial [Member]
Impaired loans by loan portfolio
Recorded Investment	1,649	2,001	2,726
Unpaid Principal Balance	1,859	2,045	2,851
Related Allowance	412	1,150	1,084
Average Recorded Investment	2,032	2,572	2,883
Interest Income Recognized	98	125	143
With Allowance Recorded [Member] \| Commercial Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	14,747	25,233	20,869
Unpaid Principal Balance	15,514	25,377	21,438
Related Allowance	197	765	516
Average Recorded Investment	15,650	25,595	21,678
Interest Income Recognized	842	1,326	1,340
With Allowance Recorded [Member] \| Small Business [Member]
Impaired loans by loan portfolio
Recorded Investment	396	429	1,194
Unpaid Principal Balance	458	462	1,228
Related Allowance	7	109	353
Average Recorded Investment	456	459	1,255
Interest Income Recognized	32	28	77
With Allowance Recorded [Member] \| Residential Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	12,616	13,228	12,828
Unpaid Principal Balance	13,727	14,197	13,601
Related Allowance	1,500	1,564	1,302
Average Recorded Investment	12,817	13,405	13,014
Interest Income Recognized	537	515	560
With Allowance Recorded [Member] \| Home Equity [Member]
Impaired loans by loan portfolio
Recorded Investment	1,161	627	316
Unpaid Principal Balance	1,264	694	389
Related Allowance	262	116	35
Average Recorded Investment	1,203	642	324
Interest Income Recognized	46	26	23
With Allowance Recorded [Member] \| Consumer - Other [Member]
Impaired loans by loan portfolio
Recorded Investment	530	852	1,429
Unpaid Principal Balance	530	856	1,453
Related Allowance	38	70	130
Average Recorded Investment	580	954	1,610
Interest Income Recognized	$ 22	$ 33	$ 60

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5258-111524

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