Allowance for Credit Losses on Loans (Allowance for Loan Losses Rollforward Analysis) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	$ 39,343	$ 36,317	$ 38,027	$ 39,088
Charge-offs	(44)	(63)	(157)	(122)
Recoveries	14	9	43	226
Provision	900	600	2,300	(2,329)
Allowance, Ending Balance	40,213	36,863	40,213	36,863
Commercial Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	22,026	17,197	18,435	18,933
Charge-offs	0	0	0	0
Recoveries	0	0	0	145
Provision	1,659	414	5,250	(1,467)
Allowance, Ending Balance	23,685	17,611	23,685	17,611
Commercial & Industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	9,428	10,332	10,356	10,832
Charge-offs	(5)	(10)	(25)	(19)
Recoveries	1	1	10	22
Provision	(1,002)	24	(1,919)	(488)
Allowance, Ending Balance	8,422	10,347	8,422	10,347
Total Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	31,454	27,529	28,791	29,765
Charge-offs	(5)	(10)	(25)	(19)
Recoveries	1	1	10	167
Provision	657	438	3,331	(1,955)
Allowance, Ending Balance	32,107	27,958	32,107	27,958
Residential Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	6,442	7,308	7,740	7,860
Charge-offs	0	0	0	0
Recoveries	0	0	0	21
Provision	276	139	(1,022)	(434)
Allowance, Ending Balance	6,718	7,447	6,718	7,447
Home Equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	1,039	1,040	1,115	1,069
Charge-offs	0	0	0	0
Recoveries	7	0	10	4
Provision	(54)	31	(133)	(2)
Allowance, Ending Balance	992	1,071	992	1,071
Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	408	440	381	394
Charge-offs	(39)	(53)	(132)	(103)
Recoveries	6	8	23	34
Provision	21	(8)	124	62
Allowance, Ending Balance	396	387	396	387
Total Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	1,447	1,480	1,496	1,463
Charge-offs	(39)	(53)	(132)	(103)
Recoveries	13	8	33	38
Provision	(33)	23	(9)	60
Allowance, Ending Balance	$ 1,388	$ 1,458	$ 1,388	$ 1,458