Loans, Allowance for Loan Losses and Credit Quality (ALLL - by category) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Summary of changes in allowance for loan losses
Beginning Balance	$ 55,825	$ 55,100
Charge-offs	(537)	(1,525)
Recoveries	619	1,440
Provision (benefit) for loan losses	525	(500)
Ending Balance	56,432	54,515
Ending Balance: Individually Evaluated for Impairment	2,507	2,318	$ 1,930
Ending Balance: Collectively Evaluated for Impairment	53,925	52,197
Commercial and Industrial [Member]
Summary of changes in allowance for loan losses
Beginning Balance	13,802	15,573
Charge-offs	(2)	(561)
Recoveries	138	379
Provision (benefit) for loan losses	(453)	(834)
Ending Balance	13,485	14,557
Ending Balance: Individually Evaluated for Impairment	222	308	183
Ending Balance: Collectively Evaluated for Impairment	13,263	14,249
Commercial Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	27,327	25,873
Charge-offs	0	(141)
Recoveries	189	685
Provision (benefit) for loan losses	1,079	(132)
Ending Balance	28,595	26,285
Ending Balance: Individually Evaluated for Impairment	802	265	204
Ending Balance: Collectively Evaluated for Impairment	27,793	26,020
Construction Loans [Member]
Summary of changes in allowance for loan losses
Beginning Balance	5,366	3,945
Charge-offs	0	0
Recoveries	0	0
Provision (benefit) for loan losses	(266)	197
Ending Balance	5,100	4,142
Ending Balance: Individually Evaluated for Impairment	0	0
Ending Balance: Collectively Evaluated for Impairment	5,100	4,142
Small Business [Member]
Summary of changes in allowance for loan losses
Beginning Balance	1,264	1,171
Charge-offs	(63)	(150)
Recoveries	21	67
Provision (benefit) for loan losses	119	134
Ending Balance	1,341	1,222
Ending Balance: Individually Evaluated for Impairment	3	5	4
Ending Balance: Collectively Evaluated for Impairment	1,338	1,217
Residential Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	2,590	2,834
Charge-offs	(19)	(185)
Recoveries	0	45
Provision (benefit) for loan losses	(4)	32
Ending Balance	2,567	2,726
Ending Balance: Individually Evaluated for Impairment	1,223	1,453	1,278
Ending Balance: Collectively Evaluated for Impairment	1,344	1,273
Consumer Home Equity [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,889	4,956
Charge-offs	(147)	(161)
Recoveries	27	72
Provision (benefit) for loan losses	146	39
Ending Balance	4,915	4,906
Ending Balance: Individually Evaluated for Impairment	231	253	238
Ending Balance: Collectively Evaluated for Impairment	4,684	4,653
Consumer Other [Member]
Summary of changes in allowance for loan losses
Beginning Balance	587	748
Charge-offs	(306)	(327)
Recoveries	244	192
Provision (benefit) for loan losses	(96)	64
Ending Balance	429	677
Ending Balance: Individually Evaluated for Impairment	26	34	$ 23
Ending Balance: Collectively Evaluated for Impairment	$ 403	$ 643