Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	$ 2,593	$ 2,411	$ 7,668	$ 7,681
Employee benefit and retirement-related accounts	2,568	2,353	7,507	7,384
Investment management and investment advisory agency accounts	3,407	3,000	9,842	9,403
Other	532	452	1,514	1,404
Non-sufficient funds (NSF) fees	943	1,722	2,864	4,658
Demand deposit account (DDA) charges	1,060	996	3,167	2,425
Other	106	141	360	413
Credit card	719	734	2,132	2,091
HELOC	100	103	297	297
Installment	39	40	123	128
Real estate	1,497	1,692	4,462	8,685
Commercial	260	387	937	1,514
Debit card fee income	6,652	6,514	19,939	19,371
Bank owned life insurance income	1,448	1,185	3,965	4,734
ATM Fees	575	610	1,661	1,725
Gains (Losses) on Sales of Other Real Estate	(6)	5,607	(3)	5,611
Real Estate Owned, Valuation Allowance, Valuation Increase	0	12,009	15	12,039
Gain on equity securities, net	998	58	618	3,120
Other components of net periodic benefit income	1,893	3,027	5,679	9,081
Other	2,329	3,653	4,368	7,779
Total other income	27,713	46,694	77,115	109,543
Bank Servicing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,615	2,956	7,951	12,715
Within Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,300	1,400	4,100	4,300
Out of Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,300	1,600	3,900	8,400
PNB [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	2,593	2,411	7,668	7,681
Employee benefit and retirement-related accounts	2,568	2,353	7,507	7,384
Investment management and investment advisory agency accounts	3,407	3,000	9,842	9,403
Other	532	452	1,514	1,404
Non-sufficient funds (NSF) fees	943	1,722	2,864	4,658
Demand deposit account (DDA) charges	1,060	996	3,167	2,425
Other	106	141	360	413
Credit card	719	734	2,132	2,091
HELOC	100	103	297	297
Installment	39	40	123	128
Real estate	1,497	1,692	4,462	8,685
Commercial	260	384	802	1,039
Debit card fee income	6,652	6,514	19,939	19,371
Bank owned life insurance income	1,394	1,133	3,807	3,356
ATM Fees	575	610	1,661	1,725
Gains (Losses) on Sales of Other Real Estate	(6)	0	(3)	4
Real Estate Owned, Valuation Allowance, Valuation Increase	0	0	15	30
Gain on equity securities, net	1,264	25	1,146	2,285
Other components of net periodic benefit income	1,857	2,955	5,571	8,864
Other	2,328	3,653	4,367	8,177
Total other income	27,888	28,918	77,241	89,420
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	3	135	475
Debit card fee income	0	0	0	0
Bank owned life insurance income	54	52	158	1,378
ATM Fees	0	0	0	0
Gains (Losses) on Sales of Other Real Estate	0	5,607	0	5,607
Real Estate Owned, Valuation Allowance, Valuation Increase	0	12,009	0	12,009
Gain on equity securities, net	(266)	33	(528)	835
Other components of net periodic benefit income	36	72	108	217
Other	1	0	1	(398)
Total other income	$ (175)	$ 17,776	$ (126)	$ 20,123