Loans, Allowance for Loan Losses and Credit Quality (ALLL - by category) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Summary of changes in allowance for loan losses
Beginning Balance	$ 54,515	$ 53,629	$ 55,100	$ 53,239
Charge-offs	(1,099)	(2,150)	(2,624)	6,716
Recoveries	879	809	2,319	1,263
Provision for loan losses	700	2,250	200	6,752
Ending Balance	54,995	54,538	54,995	54,538
Ending Balance: Individually Evaluated for Impairment	2,132	2,730	2,132	2,730	$ 2,416
Ending Balance: Collectively Evaluated for Impairment	52,863	51,808	52,863	51,808
Commercial and Industrial [Member]
Summary of changes in allowance for loan losses
Beginning Balance	14,557	15,601	15,573	15,622
Charge-offs	(473)	(470)	(1,034)	1,253
Recoveries	502	128	881	207
Provision for loan losses	693	670	(141)	1,353
Ending Balance	15,279	15,929	15,279	15,929
Ending Balance: Individually Evaluated for Impairment	310	472	310	472	412
Ending Balance: Collectively Evaluated for Impairment	14,969	15,457	14,969	15,457
Commercial Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	26,285	24,917	25,873	24,541
Charge-offs	(67)	(660)	(208)	3,582
Recoveries	169	197	854	265
Provision for loan losses	(28)	641	(160)	3,871
Ending Balance	26,359	25,095	26,359	25,095
Ending Balance: Individually Evaluated for Impairment	201	292	201	292	197
Ending Balance: Collectively Evaluated for Impairment	26,158	24,803	26,158	24,803
Construction Loans [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,142	3,570	3,945	3,371
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for loan losses	(71)	187	126	386
Ending Balance	4,071	3,757	4,071	3,757
Ending Balance: Individually Evaluated for Impairment	0	0	0	0
Ending Balance: Collectively Evaluated for Impairment	4,071	3,757	4,071	3,757
Small Business [Member]
Summary of changes in allowance for loan losses
Beginning Balance	1,222	1,207	1,171	1,215
Charge-offs	(47)	(128)	(196)	396
Recoveries	66	92	132	139
Provision for loan losses	7	(17)	141	196
Ending Balance	1,248	1,154	1,248	1,154
Ending Balance: Individually Evaluated for Impairment	4	45	4	45	7
Ending Balance: Collectively Evaluated for Impairment	1,244	1,109	1,244	1,109
Residential Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	2,726	2,829	2,834	2,760
Charge-offs	(17)	(326)	(202)	454
Recoveries	1	190	46	190
Provision for loan losses	(159)	186	(127)	383
Ending Balance	2,551	2,879	2,551	2,879
Ending Balance: Individually Evaluated for Impairment	1,337	1,599	1,337	1,599	1,500
Ending Balance: Collectively Evaluated for Impairment	1,214	1,280	1,214	1,280
Consumer Home Equity [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,906	4,758	4,956	5,036
Charge-offs	(248)	(308)	(411)	402
Recoveries	31	55	105	148
Provision for loan losses	182	464	221	187
Ending Balance	4,871	4,969	4,871	4,969
Ending Balance: Individually Evaluated for Impairment	250	273	250	273	262
Ending Balance: Collectively Evaluated for Impairment	4,621	4,696	4,621	4,696
Consumer Other [Member]
Summary of changes in allowance for loan losses
Beginning Balance	677	747	748	694
Charge-offs	(247)	(258)	(573)	629
Recoveries	110	147	301	314
Provision for loan losses	76	119	140	376
Ending Balance	616	755	616	755
Ending Balance: Individually Evaluated for Impairment	30	49	30	49	$ 38
Ending Balance: Collectively Evaluated for Impairment	$ 586	$ 706	$ 586	$ 706