Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	$ 2,506	$ 2,387
Employee benefit and retirement-related accounts	2,560	2,301
Investment management and investment advisory agency accounts	3,260	3,009
Other	471	476
Non-sufficient funds (NSF) fees	1,417	1,134
Demand deposit account (DDA) charges	516	789
Other	141	131
Credit card	642	580
HELOC	89	89
Installment	43	34
Real estate	3,719	8,438
Commercial	326	476
Debit card fee income	6,126	6,086
Bank owned life insurance income	1,175	1,165
ATM Fees	532	530
Gains (Losses) on Sales of Other Real Estate	0	(33)
Gain on equity securities, net	2,353	1,810
Other components of net periodic benefit income	3,027	2,038
Other	2,753	2,649
Total other income	31,656	34,089
Bank Servicing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,819	9,617
Within Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,200	1,300
Out of Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3,600	8,300
PNB [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	2,506	2,387
Employee benefit and retirement-related accounts	2,560	2,301
Investment management and investment advisory agency accounts	3,260	3,009
Other	471	476
Non-sufficient funds (NSF) fees	1,417	1,134
Demand deposit account (DDA) charges	516	789
Other	141	131
Credit card	642	580
HELOC	89	89
Installment	43	34
Real estate	3,719	8,438
Commercial	354	418
Debit card fee income	6,126	6,086
Bank owned life insurance income	1,093	1,085
ATM Fees	532	530
Gains (Losses) on Sales of Other Real Estate	0	(33)
Gain on equity securities, net	2,219	834
Other components of net periodic benefit income	2,955	1,987
Other	2,604	2,525
Total other income	31,247	32,800
All Other [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	0	0
Employee benefit and retirement-related accounts	0	0
Investment management and investment advisory agency accounts	0	0
Other	0	0
Non-sufficient funds (NSF) fees	0	0
Demand deposit account (DDA) charges	0	0
Other	0	0
Credit card	0	0
HELOC	0	0
Installment	0	0
Real estate	0	0
Commercial	(28)	58
Debit card fee income	0	0
Bank owned life insurance income	82	80
ATM Fees	0	0
Gains (Losses) on Sales of Other Real Estate	0	0
Gain on equity securities, net	134	976
Other components of net periodic benefit income	72	51
Other	149	124
Total other income	$ 409	$ 1,289