Allowance for Loan Losses (Allowance for Loan Losses Rollforward Analysis) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		$ 26,488	$ 26,004
Charge-offs		(690)	(79)
Recoveries		66	121
Provision		0	400
Allowance, Ending Balance		25,864	26,446
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance	[1]	12,729	11,166
Charge-offs	[1]	(627)	0
Recoveries	[1]	25	0
Provision	[1]	(308)	1,200
Allowance, Ending Balance	[1]	11,819	12,366
Commercial & Industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance	[2]	5,580	6,992
Charge-offs	[2]	(6)	(2)
Recoveries	[2]	29	107
Provision	[2]	268	(800)
Allowance, Ending Balance	[2]	5,871	6,297
Total Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		18,309	18,158
Charge-offs		(633)	(2)
Recoveries		54	107
Provision		(40)	400
Allowance, Ending Balance		17,690	18,663
Residential Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		5,427	5,252
Charge-offs		0	0
Recoveries		0	4
Provision		67	103
Allowance, Ending Balance		5,494	5,359
Home Equity
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		2,412	1,889
Charge-offs		(35)	(45)
Recoveries		7	2
Provision		(192)	(106)
Allowance, Ending Balance		2,192	1,740
Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		340	705
Charge-offs		(22)	(32)
Recoveries		5	8
Provision		165	3
Allowance, Ending Balance		488	684
Total Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance, Beginning Balance		2,752	2,594
Charge-offs		(57)	(77)
Recoveries		12	10
Provision		(27)	(103)
Allowance, Ending Balance		$ 2,680	$ 2,424

[1] Commercial real estate loans.

[2] Commercial & industrial loans.