Loans and Leases, Changes in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 61,007	$ 58,862
Provision / (recapture) for credit losses	0	1,250
Charge-offs	(9)	(8)
Recoveries	34	71
Net (charge-offs) / recoveries	25	63
Balance at end of period	61,032	60,175
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	38,149	36,312
Provision / (recapture) for credit losses	552	1,802
Charge-offs	0	0
Recoveries	0	0
Net (charge-offs) / recoveries	0	0
Balance at end of period	32,511	38,114
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	(6,190)
Construction [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,456	1,643
Provision / (recapture) for credit losses	466	4
Charge-offs	0	0
Recoveries	0	0
Net (charge-offs) / recoveries	0	0
Balance at end of period	3,777	1,647
Construction [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,855
Residential & Home Equity [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	2,847	2,984
Provision / (recapture) for credit losses	866	(135)
Charge-offs	0	0
Recoveries	14	32
Net (charge-offs) / recoveries	14	32
Balance at end of period	6,759	2,881
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	3,032
Commercial & Agricultural [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	16,954	14,775
Provision / (recapture) for credit losses	(1,700)	(584)
Charge-offs	0	0
Recoveries	18	32
Net (charge-offs) / recoveries	18	32
Balance at end of period	16,098	14,223
Commercial & Agricultural [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	826
Commercial Leases [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	938	1,731
Provision / (recapture) for credit losses	(101)	(57)
Charge-offs	0	0
Recoveries	0	0
Net (charge-offs) / recoveries	0	0
Balance at end of period	1,466	1,674
Commercial Leases [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASC 326 [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	629
Consumer and Other [Member]
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	663	1,417
Provision / (recapture) for credit losses	(83)	220
Charge-offs	(9)	(8)
Recoveries	2	7
Net (charge-offs) / recoveries	(7)	(1)
Balance at end of period	421	$ 1,636
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	$ (152)