Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	$ 2,387	$ 2,171
Employee benefit and retirement-related accounts	2,301	1,916
Investment management and investment advisory agency accounts	3,009	2,642
Other	476	384
Non-sufficient funds (NSF) fees	1,134	1,615
Demand deposit account (DDA) charges	789	761
Other	131	152
Credit card	580	597
HELOC	89	98
Installment	34	53
Real estate	8,438	2,647
Commercial	476	371
Debit card fee income	6,086	4,960
Bank owned life insurance income	1,165	1,248
ATM Fees	530	412
Gains (Losses) on Sales of Other Real Estate	(33)	(196)
(Gain) loss on equity securities, net	1,810	(973)
Other components of net periodic benefit income	2,038	1,988
Other	2,649	1,640
Total other income	34,089	22,486
Bank Servicing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	9,617	3,766
Within Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,300	1,300
Out of Scope [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	8,300	2,500
PNB [Member]
Disaggregation of Revenue [Line Items]
Personal trust and agency accounts	2,387	2,171
Employee benefit and retirement-related accounts	2,301	1,916
Investment management and investment advisory agency accounts	3,009	2,642
Other	476	384
Non-sufficient funds (NSF) fees	1,134	1,615
Demand deposit account (DDA) charges	789	761
Other	131	152
Credit card	580	596
HELOC	89	98
Installment	34	53
Real estate	8,438	2,647
Commercial	418	371
Debit card fee income	6,086	4,960
Bank owned life insurance income	1,085	1,166
ATM Fees	530	412
Gains (Losses) on Sales of Other Real Estate	(33)	(196)
(Gain) loss on equity securities, net	834	166
Other components of net periodic benefit income	1,987	1,940
Other	2,525	1,627
Total other income	32,800	23,481
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	1
HELOC	0	0
Installment	0	0
Real estate	0	0
Commercial	58	0
Debit card fee income	0	0
Bank owned life insurance income	80	82
ATM Fees	0	0
Gains (Losses) on Sales of Other Real Estate	0	0
(Gain) loss on equity securities, net	976	(1,139)
Other components of net periodic benefit income	51	48
Other	124	13
Total other income	$ 1,289	$ (995)