Loans, Allowance for Loan Losses and Credit Quality (Int Inc. Recognized on Impaired Loans by Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest income recognized on impaired loans
Average Recorded Investment	$ 45,858	$ 59,053	$ 46,216	$ 59,834
Interest Income Recognized	392	764	785	1,582
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	24,221	27,252	24,473	27,843
Interest Income Recognized	223	373	447	764
WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	21,637	31,801	21,743	31,991
Interest Income Recognized	169	391	338	818
Commercial and Industrial [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	2,349	2,842	2,415	2,927
Interest Income Recognized	15	40	30	81
Commercial and Industrial [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	2,458	2,712	2,487	2,749
Interest Income Recognized	6	31	12	62
Commercial Real Estate [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	12,205	14,467	12,327	15,044
Interest Income Recognized	103	227	207	471
Commercial Real Estate [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	6,716	15,231	6,744	15,292
Interest Income Recognized	51	204	102	406
Construction Loans [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment		310		311
Interest Income Recognized		3		7
Small Business [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	677	459	691	471
Interest Income Recognized	5	6	11	13
Small Business [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	401	442	410	453
Interest Income Recognized	6	7	13	15
Residential Real Estate [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	4,315	3,385	4,331	3,403
Interest Income Recognized	51	40	101	79
Residential Real Estate [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	10,394	11,608	10,424	11,662
Interest Income Recognized	91	128	184	295
Consumer - Home Equity [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	4,537	4,585	4,567	4,613
Interest Income Recognized	46	51	93	102
Consumer - Home Equity [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	1,311	1,336	1,316	1,345
Interest Income Recognized	13	16	23	31
Consumer - Other [Member] \| WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	138	1,204	142	1,074
Interest Income Recognized	3	6	5	11
Consumer - Other [Member] \| WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	357	472	362	490
Interest Income Recognized	$ 2	$ 5	$ 4	$ 9

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=66008989&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=66008989&loc=d3e5258-111524

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+ References

Reference 1: 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=66008989&loc=d3e5258-111524

Reference 2: 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=66008989&loc=d3e5212-111524

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