Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	$ 2,571	$ 2,764	$ 5,075	$ 5,270
Employee benefit and retirement-related accounts	2,467	2,471	4,939	5,031
Investment management and investment advisory agency accounts	3,273	3,143	6,435	6,403
Other	505	481	982	952
Non-sufficient funds (NSF) fees	860	1,519	1,921	2,936
Demand deposit account (DDA) charges	1,069	913	2,107	1,429
Other	112	131	254	272
Credit card	730	715	1,413	1,357
HELOC	108	105	197	194
Installment	35	45	84	88
Real estate	1,510	3,274	2,965	6,993
Commercial	256	801	677	1,127
Debit card fee income	6,830	6,731	13,287	12,857
Bank owned life insurance income	1,332	2,374	2,517	3,549
ATM Fees	553	583	1,086	1,115
Gains (Losses) on Sales of Other Real Estate	12	4	3	4
Real Estate Owned, Valuation Allowance, Valuation Increase	0	0	15	30
Loss (gain) on equity securities, net	25	709	(380)	3,062
Other components of net periodic benefit income	1,893	3,027	3,786	6,054
Other	874	1,403	2,039	4,126
Total other income	25,015	31,193	49,402	62,849
Bank Servicing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,639	4,940	5,336	9,759
Within Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,300	1,700	2,700	3,000
Out of Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,300	3,200	2,600	6,800
PNB [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	2,571	2,764	5,075	5,270
Employee benefit and retirement-related accounts	2,467	2,471	4,939	5,031
Investment management and investment advisory agency accounts	3,273	3,143	6,435	6,403
Other	505	481	982	952
Non-sufficient funds (NSF) fees	860	1,519	1,921	2,936
Demand deposit account (DDA) charges	1,069	913	2,107	1,429
Other	112	131	254	272
Credit card	730	715	1,413	1,357
HELOC	108	105	197	194
Installment	35	45	84	88
Real estate	1,510	3,274	2,965	6,993
Commercial	256	301	542	655
Debit card fee income	6,830	6,731	13,287	12,857
Bank owned life insurance income	1,279	1,130	2,413	2,223
ATM Fees	553	583	1,086	1,115
Gains (Losses) on Sales of Other Real Estate	12	4	3	4
Real Estate Owned, Valuation Allowance, Valuation Increase	0	0	15	30
Loss (gain) on equity securities, net	189	41	(118)	2,260
Other components of net periodic benefit income	1,857	2,954	3,714	5,909
Other	875	1,950	2,039	4,524
Total other income	25,091	29,255	49,353	60,502
All Other [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	0	0	0	0
Employee benefit and retirement-related accounts	0	0	0	0
Investment management and investment advisory agency accounts	0	0	0	0
Other	0	0	0	0
Non-sufficient funds (NSF) fees	0	0	0	0
Demand deposit account (DDA) charges	0	0	0	0
Other	0	0	0	0
Credit card	0	0	0	0
HELOC	0	0	0	0
Installment	0	0	0	0
Real estate	0	0	0	0
Commercial	0	500	135	472
Debit card fee income	0	0	0	0
Bank owned life insurance income	53	1,244	104	1,326
ATM Fees	0	0	0	0
Gains (Losses) on Sales of Other Real Estate	0	0	0	0
Real Estate Owned, Valuation Allowance, Valuation Increase	0	0	0	0
Loss (gain) on equity securities, net	(164)	668	(262)	802
Other components of net periodic benefit income	36	73	72	145
Other	(1)	(547)	0	(398)
Total other income	$ (76)	$ 1,938	$ 49	$ 2,347