Accumulated Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 893,421	$ 852,401	$ 764,230
Other comprehensive income (loss) before reclassifications	(40,729)	14,879	16,545
Amounts reclassified from accumulated other comprehensive income	1,409	(5,652)	539
Net current-period other comprehensive income (loss)	(39,320)	9,227	17,084
Ending balance	1,230,575	893,421	852,401
Unrealized Gain (Loss) on Securities Available for Sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	15,749	7,504	(9,494)
Other comprehensive income (loss) before reclassifications	(41,400)	14,425	17,073
Amounts reclassified from accumulated other comprehensive income	953	(6,180)	(75)
Net current-period other comprehensive income (loss)	(40,447)	8,245	16,998
Ending balance	(24,698)	15,749	7,504
Postretirement Plans Asset (Liability)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1,399)	(2,381)	(2,467)
Other comprehensive income (loss) before reclassifications	671	454	(528)
Amounts reclassified from accumulated other comprehensive income	456	528	614
Net current-period other comprehensive income (loss)	1,127	982	86
Ending balance	(272)	(1,399)	(2,381)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	14,350	5,123	(11,961)
Ending balance	$ (24,970)	$ 14,350	$ 5,123