Allowance for Credit Losses on Loans (Allowance for Loan Losses Rollforward Analysis) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	$ 42,378	$ 39,343	$ 41,057	$ 38,027	$ 38,027
Charge-offs	(59)	(44)	(182)	(157)	(577)
Recoveries	11	14	55	43
Provision	300	900	1,700	2,300
Allowance, Ending Balance	42,630	40,213	42,630	40,213	41,057
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	25,766	22,026	24,144	18,435	18,435
Charge-offs	0	0	0	0	(373)
Recoveries	0	0	0	0
Provision	(8)	1,659	1,614	5,250
Allowance, Ending Balance	25,758	23,685	25,758	23,685	24,144
Commercial & industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	7,097	9,428	8,088	10,356	10,356
Charge-offs	(4)	(5)	(24)	(25)	(37)
Recoveries	2	1	19	10
Provision	308	(1,002)	(680)	(1,919)
Allowance, Ending Balance	7,403	8,422	7,403	8,422	8,088
Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	32,863	31,454	32,232	28,791	28,791
Charge-offs	(4)	(5)	(24)	(25)
Recoveries	2	1	19	10
Provision	300	657	934	3,331
Allowance, Ending Balance	33,161	32,107	33,161	32,107	32,232
Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	8,102	6,442	7,403	7,740	7,740
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0
Provision	(39)	276	660	(1,022)
Allowance, Ending Balance	8,063	6,718	8,063	6,718	7,403
Home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	1,080	1,039	1,048	1,115	1,115
Charge-offs	0	0	0	0	0
Recoveries	1	7	8	10
Provision	5	(54)	30	(133)
Allowance, Ending Balance	1,086	992	1,086	992	1,048
Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	333	408	374	381	381
Charge-offs	(55)	(39)	(158)	(132)	(167)
Recoveries	8	6	28	23
Provision	34	21	76	124
Allowance, Ending Balance	320	396	320	396	374
Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance, Beginning Balance	1,413	1,447	1,422	1,496	1,496
Charge-offs	(55)	(39)	(158)	(132)
Recoveries	9	13	36	33
Provision	39	(33)	106	(9)
Allowance, Ending Balance	$ 1,406	$ 1,388	$ 1,406	$ 1,388	$ 1,422