Allowance for Loan Losses (Allowance for Loan Losses Rollforward Analysis) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		$ 25,864	$ 26,446	$ 26,488	$ 26,004
Charge-offs		(103)	(642)	(793)	(721)
Recoveries		13	158	79	279
Provision		400	700	400	1,100
Allowance, Ending Balance		26,174	26,662	26,174	26,662
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance	[1]	11,819	12,366	12,729	11,166
Charge-offs	[1]	0	(400)	(627)	(400)
Recoveries	[1]	0	82	25	82
Provision	[1]	624	(113)	316	1,087
Allowance, Ending Balance	[1]	12,443	11,935	12,443	11,935
Commercial & Industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance	[2]	5,871	6,297	5,580	6,992
Charge-offs	[2]	(1)	(162)	(7)	(164)
Recoveries	[2]	4	47	33	154
Provision	[2]	768	885	1,036	85
Allowance, Ending Balance	[2]	6,642	7,067	6,642	7,067
Total Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		17,690	18,663	18,309	18,158
Charge-offs		(1)	(562)	(634)	(564)
Recoveries		4	129	58	236
Provision		1,392	772	1,352	1,172
Allowance, Ending Balance		19,085	19,002	19,085	19,002
Residential Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		5,494	5,359	5,427	5,252
Charge-offs		(5)	(32)	(5)	(32)
Recoveries		0	24	0	28
Provision		(175)	18	(108)	121
Allowance, Ending Balance		5,314	5,369	5,314	5,369
Home Equity
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		2,192	1,740	2,412	1,889
Charge-offs		(76)	(16)	(111)	(61)
Recoveries		3	4	10	6
Provision		(744)	199	(936)	93
Allowance, Ending Balance		1,375	1,927	1,375	1,927
Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		488	684	340	705
Charge-offs		(21)	(32)	(43)	(64)
Recoveries		6	1	11	9
Provision		(73)	(289)	92	(286)
Allowance, Ending Balance		400	364	400	364
Total Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		2,680	2,424	2,752	2,594
Charge-offs		(97)	(48)	(154)	(125)
Recoveries		9	5	21	15
Provision		(817)	(90)	(844)	(193)
Allowance, Ending Balance		$ 1,775	$ 2,291	$ 1,775	$ 2,291

[1] Commercial real estate loans.

[2] Commercial & industrial loans.