Loans and Leases, Changes in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 71,112	$ 62,080	$ 66,885	$ 61,007
Provision / (recapture) for credit losses	3,000	1,499	7,000	2,606
Charge-offs	(15)	(68)	(47)	(362)
Recoveries	62	106	321	366
Net (charge-offs) / recoveries	47	38	274	4
Balance at end of period	74,159	63,617	74,159	63,617
Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Commercial & Agricultural R/E [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	34,695	34,716	32,551	38,149
Provision / (recapture) for credit losses	(730)	(1,616)	1,244	(5,049)
Charge-offs	0	0	0	0
Recoveries	0	0	170	0
Net (charge-offs) / recoveries	0	0	170	0
Balance at end of period	33,965	33,100	33,965	33,100
Commercial & Agricultural R/E [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Construction [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	3,195	2,876	3,026	1,456
Provision / (recapture) for credit losses	417	119	586	1,539
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net (charge-offs) / recoveries	0	0	0	0
Balance at end of period	3,612	2,995	3,612	2,995
Construction [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Residential & Home Equity [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	7,179	6,874	7,508	2,847
Provision / (recapture) for credit losses	268	(15)	(78)	3,893
Charge-offs	0	0	(14)	0
Recoveries	11	6	42	125
Net (charge-offs) / recoveries	11	6	28	125
Balance at end of period	7,458	6,865	7,458	6,865
Residential & Home Equity [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Commercial & Agricultural [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	24,194	15,808	21,705	16,954
Provision / (recapture) for credit losses	2,748	3,063	5,196	2,058
Charge-offs	0	(48)	0	(324)
Recoveries	43	92	84	227
Net (charge-offs) / recoveries	43	44	84	(97)
Balance at end of period	26,985	18,915	26,985	18,915
Commercial & Agricultural [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Commercial Leases [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,657	1,645	1,924	938
Provision / (recapture) for credit losses	310	(57)	43	650
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net (charge-offs) / recoveries	0	0	0	0
Balance at end of period	1,967	1,588	1,967	1,588
Commercial Leases [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				0
Consumer and Other [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	192	161	171	663
Provision / (recapture) for credit losses	(13)	5	9	(485)
Charge-offs	(15)	(20)	(33)	(38)
Recoveries	8	8	25	14
Net (charge-offs) / recoveries	(7)	(12)	(8)	(24)
Balance at end of period	$ 172	$ 154	$ 172	154
Consumer and Other [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period				$ 0