Loans, Allowance for Loan Losses and Credit Quality (ALLL - by category) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Summary of changes in allowance for loan losses
Beginning Balance	$ 54,995	$ 54,538	$ 55,100	$ 53,239
Charge-offs	(1,165)	(1,906)	(3,788)	(8,622)
Recoveries	575	472	2,893	1,735
Provision for loan losses	800	1,901	1,000	8,653
Ending Balance	55,205	55,005	55,205	55,005
Ending Balance: Individually Evaluated for Impairment	2,090	2,699	2,090	2,699	$ 2,416
Ending Balance: Collectively Evaluated for Impairment	53,115	52,306	53,115	52,306
Commercial and Industrial [Member]
Summary of changes in allowance for loan losses
Beginning Balance	15,279	15,929	15,573	15,622
Charge-offs	(497)	(504)	(1,531)	(1,757)
Recoveries	22	6	903	213
Provision for loan losses	(518)	91	(659)	1,444
Ending Balance	14,286	15,522	14,286	15,522
Ending Balance: Individually Evaluated for Impairment	252	541	252	541	412
Ending Balance: Collectively Evaluated for Impairment	14,034	14,981	14,034	14,981
Commercial Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	26,359	25,095	25,873	24,541
Charge-offs	(28)	(691)	(236)	(4,273)
Recoveries	152	57	1,006	322
Provision for loan losses	582	1,248	422	5,119
Ending Balance	27,065	25,709	27,065	25,709
Ending Balance: Individually Evaluated for Impairment	225	315	225	315	197
Ending Balance: Collectively Evaluated for Impairment	26,840	25,394	26,840	25,394
Construction Loans [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,071	3,757	3,945	3,371
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for loan losses	422	356	548	742
Ending Balance	4,493	4,113	4,493	4,113
Ending Balance: Individually Evaluated for Impairment	0	0	0	0
Ending Balance: Collectively Evaluated for Impairment	4,493	4,113	4,493	4,113
Small Business [Member]
Summary of changes in allowance for loan losses
Beginning Balance	1,248	1,154	1,171	1,215
Charge-offs	(2)	(73)	(198)	(469)
Recoveries	57	29	189	168
Provision for loan losses	(20)	45	121	241
Ending Balance	1,283	1,155	1,283	1,155
Ending Balance: Individually Evaluated for Impairment	28	10	28	10	7
Ending Balance: Collectively Evaluated for Impairment	1,255	1,145	1,255	1,145
Residential Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	2,551	2,879	2,834	2,760
Charge-offs	(40)	(199)	(242)	(653)
Recoveries	6	178	52	368
Provision for loan losses	75	(36)	(52)	347
Ending Balance	2,592	2,822	2,592	2,822
Ending Balance: Individually Evaluated for Impairment	1,313	1,521	1,313	1,521	1,500
Ending Balance: Collectively Evaluated for Impairment	1,279	1,301	1,279	1,301
Consumer Home Equity [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,871	4,969	4,956	5,036
Charge-offs	(249)	(160)	(659)	(562)
Recoveries	130	67	234	215
Provision for loan losses	128	71	349	258
Ending Balance	4,880	4,947	4,880	4,947
Ending Balance: Individually Evaluated for Impairment	245	269	245	269	262
Ending Balance: Collectively Evaluated for Impairment	4,635	4,678	4,635	4,678
Consumer Other [Member]
Summary of changes in allowance for loan losses
Beginning Balance	616	755	748	694
Charge-offs	(349)	(279)	(922)	(908)
Recoveries	208	135	509	449
Provision for loan losses	131	126	271	502
Ending Balance	606	737	606	737
Ending Balance: Individually Evaluated for Impairment	27	43	27	43	$ 38
Ending Balance: Collectively Evaluated for Impairment	$ 579	$ 694	$ 579	$ 694