Loans, Allowance for Loan Losses and Credit Quality (Int Inc. Recognized on Impaired Loans by Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest income recognized on impaired loans
Average Recorded Investment	$ 58,474	$ 66,057	$ 59,804	$ 67,865
Interest Income Recognized	529	672	1,731	2,080
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	25,077	29,655	25,908	30,715
Interest Income Recognized	194	293	661	904
WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	33,397	36,402	33,896	37,150
Interest Income Recognized	335	379	1,070	1,176
Commercial and Industrial [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	2,080	4,411	2,204	4,743
Interest Income Recognized	11	47	41	155
Commercial and Industrial [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	3,687	3,889	3,894	4,285
Interest Income Recognized	10	24	57	98
Commercial Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	13,876	16,517	14,433	17,098
Interest Income Recognized	89	154	337	492
Commercial Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	15,830	17,509	15,993	17,674
Interest Income Recognized	204	233	609	700
Construction Loans [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	307		309
Interest Income Recognized	0
Small Business [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	465	840	484	889
Interest Income Recognized	4	8	14	25
Small Business [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	540	427	564	452
Interest Income Recognized	7	7	22	22
Residential Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	3,566	2,806	3,601	2,836
Interest Income Recognized	42	34	123	71
Residential Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	11,698	12,841	11,764	12,959
Interest Income Recognized	106	106	358	324
Consumer - Home Equity [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	4,585	4,405	4,670	4,456
Interest Income Recognized	44	45	134	136
Consumer - Home Equity [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	1,221	1,111	1,238	1,124
Interest Income Recognized	4	4	13	15
Consumer - Other [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	198	365	207	382
Interest Income Recognized	4	5	12	19
Consumer - Other [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	421	625	443	656
Interest Income Recognized	$ 4	$ 5	$ 11	$ 17