Securities (Details) $ in Thousands	9 Months Ended
Sep. 30, 2020 USD ($) security	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) security
Securities available for sale
Securities available for sale, Percent	100.00%		100.00%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 362,811		$ 351,069
Gross Unrealized Gains	12,532		4,564
Gross Unrealized (Losses)	(88)		(330)
Amortized Cost
Due in one year or less	46,608
Due after one year through five years	219,240
Due after five years through ten years	77,290
Due over ten years	19,673
Fair Value
Due in one year or less	46,887
Due after one year through five years	226,723
Due after five years through ten years	81,722
Due over ten years	19,923
Carrying value of investment securities pledged to collateralize short-term borrowings	375,255		$ 355,303
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Sales proceeds	313	$ 12,467
Gross realized gains	10	24
Gross realized losses	$ 0	$ 52
Less than 12 months
Number of securities \| security	24		77
Fair Value	$ 18,092		$ 45,813
Unrealized Loss	$ (81)		$ (255)
Percentage	0.45%		0.56%
12 months or more
Number of securities \| security	5		27
Fair Value	$ 621		$ 21,549
Unrealized Loss	$ (7)		$ (75)
Percentage	1.13%		0.35%
Total
Number of securities \| security	29		104
Fair Value	$ 18,713		$ 67,362
Unrealized Loss	$ (88)		$ (330)
Percentage	0.47%		0.49%
Collateralized Securities [Member]
Fair Value
Carrying value of investment securities pledged to collateralize short-term borrowings	$ 13,750
U.S. Treasury [Member]
Securities available for sale
Securities available for sale, Percent	40.46%		36.19%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 145,999		$ 127,096
Gross Unrealized Gains	5,836		1,626
Gross Unrealized (Losses)	0		(137)
Fair Value
Carrying value of investment securities pledged to collateralize short-term borrowings	$ 151,835		$ 128,585
Less than 12 months
Number of securities \| security	0		11
Fair Value	$ 0		$ 27,932
Unrealized Loss	$ 0		$ (136)
Percentage	0.00%		0.49%
12 months or more
Number of securities \| security	0		1
Fair Value	$ 0		$ 2,495
Unrealized Loss	$ 0		$ (1)
Percentage	0.00%		0.04%
Total
Number of securities \| security	0		12
Fair Value	$ 0		$ 30,427
Unrealized Loss	$ 0		$ (137)
Percentage	0.00%		0.45%
Other securities [Member]
Securities available for sale
Securities available for sale, Percent	6.72%		4.29%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 25,203		$ 15,287
Gross Unrealized Gains	37		0
Gross Unrealized (Losses)	(31)		(58)
Fair Value
Carrying value of investment securities pledged to collateralize short-term borrowings	$ 25,209		$ 15,229
Less than 12 months
Number of securities \| security	5		0
Fair Value	$ 12,540		$ 0
Unrealized Loss	$ (31)		$ 0
Percentage	0.25%		0.00%
12 months or more
Number of securities \| security	0		6
Fair Value	$ 0		$ 15,229
Unrealized Loss	$ 0		$ (58)
Percentage	0.00%		0.38%
Total
Number of securities \| security	5		6
Fair Value	$ 12,540		$ 15,229
Unrealized Loss	$ (31)		$ (58)
Percentage	0.25%		0.38%
State and political subdivisions [Member]
Securities available for sale
Securities available for sale, Percent	52.82%		59.52%
Available-for-sale Securities Reconciliation [Abstract]
Amortized Cost	$ 191,609		$ 208,686
Gross Unrealized Gains	6,659		2,938
Gross Unrealized (Losses)	(57)		(135)
Fair Value
Carrying value of investment securities pledged to collateralize short-term borrowings	$ 198,211		$ 211,489
Less than 12 months
Number of securities \| security	19		66
Fair Value	$ 5,552		$ 17,881
Unrealized Loss	$ (50)		$ (119)
Percentage	0.90%		0.67%
12 months or more
Number of securities \| security	5		20
Fair Value	$ 621		$ 3,825
Unrealized Loss	$ (7)		$ (16)
Percentage	1.13%		0.42%
Total
Number of securities \| security	24		86
Fair Value	$ 6,173		$ 21,706
Unrealized Loss	$ (57)		$ (135)
Percentage	0.92%		0.62%

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