Other Comprehensive Income - Components of Other Comprehensive Income and Related Tax Effects (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss)	$ (15,468)	$ 8,135	$ 10,935
Available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassifications	(19,526)	12,494	13,732
Reclassifications	(783)	(2,190)	(148)
Net unrealized gain (loss)	(20,309)	10,304	13,584
Tax effect	4,265	(2,164)	(2,852)
Total other comprehensive income (loss)	(16,044)	8,140	10,732
Unrealized gain on postretirement benefits plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassifications	391	277	518
Reclassifications	(43)	0	23
Net unrealized gain (loss)	348	277	541
Tax effect	(73)	(58)	(113)
Total other comprehensive income (loss)	275	219	428
Unrealized loss on interest rate swap
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassifications	105	(508)	(347)
Reclassifications	276	224	63
Net unrealized gain (loss)	381	(284)	(284)
Tax effect	(80)	60	59
Total other comprehensive income (loss)	$ 301	$ (224)	$ (225)