Loans, Allowance for Loan Losses and Credit Quality (ALLL - by category) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Summary of changes in allowance for loan losses
Beginning Balance	$ 54,538	$ 52,976	$ 53,239	$ 51,834
Charge-offs	(1,906)	(2,370)	(8,622)	(6,421)
Recoveries	472	306	1,735	1,099
Provision for loan losses	1,901	2,650	8,653	7,050
Ending Balance	55,005	53,562	55,005	53,562
Ending Balance: Individually Evaluated for Impairment	2,699	5,281	2,699	5,281
Ending Balance: Collectively Evaluated for Impairment	52,306	48,281	52,306	48,281
Commercial and Industrial [Member]
Summary of changes in allowance for loan losses
Beginning Balance	15,929	14,325	15,622	13,461
Charge-offs	(504)	(866)	(1,757)	(2,591)
Recoveries	6	24	213	263
Provision for loan losses	91	1,531	1,444	3,881
Ending Balance	15,522	15,014	15,522	15,014
Ending Balance: Individually Evaluated for Impairment	541	1,174	541	1,174
Ending Balance: Collectively Evaluated for Impairment	14,981	13,840	14,981	13,840
Commercial Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	25,095	23,029	24,541	22,598
Charge-offs	(691)	(209)	(4,273)	(812)
Recoveries	57	89	322	97
Provision for loan losses	1,248	2,069	5,119	3,095
Ending Balance	25,709	24,978	25,709	24,978
Ending Balance: Individually Evaluated for Impairment	315	2,150	315	2,150
Ending Balance: Collectively Evaluated for Impairment	25,394	22,828	25,394	22,828
Commercial Construction [Member]
Summary of changes in allowance for loan losses
Beginning Balance	3,757	3,422	3,371	2,811
Charge-offs		(308)		(308)
Recoveries
Provision for loan losses	356	387	742	998
Ending Balance	4,113	3,501	4,113	3,501
Ending Balance: Individually Evaluated for Impairment	0	0	0	0
Ending Balance: Collectively Evaluated for Impairment	4,113	3,501	4,113	3,501
Small Business [Member]
Summary of changes in allowance for loan losses
Beginning Balance	1,154	1,295	1,215	1,524
Charge-offs	(73)	(84)	(469)	(505)
Recoveries	29	47	168	123
Provision for loan losses	45	(43)	241	73
Ending Balance	1,155	1,215	1,155	1,215
Ending Balance: Individually Evaluated for Impairment	10	111	10	111
Ending Balance: Collectively Evaluated for Impairment	1,145	1,104	1,145	1,104
Residential Real Estate [Member]
Summary of changes in allowance for loan losses
Beginning Balance	2,879	2,959	2,760	2,930
Charge-offs	(199)	(210)	(653)	(457)
Recoveries	178	5	368	91
Provision for loan losses	(36)	141	347	331
Ending Balance	2,822	2,895	2,822	2,895
Ending Balance: Individually Evaluated for Impairment	1,521	1,651	1,521	1,651
Ending Balance: Collectively Evaluated for Impairment	1,301	1,244	1,301	1,244
Consumer Home Equity [Member]
Summary of changes in allowance for loan losses
Beginning Balance	4,969	7,267	5,036	7,703
Charge-offs	(160)	(420)	(562)	(954)
Recoveries	67	22	215	73
Provision for loan losses	71	(1,555)	258	(1,508)
Ending Balance	4,947	5,314	4,947	5,314
Ending Balance: Individually Evaluated for Impairment	269	112	269	112
Ending Balance: Collectively Evaluated for Impairment	4,678	5,202	4,678	5,202
Consumer Other [Member]
Summary of changes in allowance for loan losses
Beginning Balance	755	679	694	807
Charge-offs	(279)	(273)	(908)	(794)
Recoveries	135	119	449	452
Provision for loan losses	126	120	502	180
Ending Balance	737	645	737	645
Ending Balance: Individually Evaluated for Impairment	43	83	43	83
Ending Balance: Collectively Evaluated for Impairment	$ 694	$ 562	$ 694	$ 562