Securities - Securities with Unrealized Losses - Securities Held-to-maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Securities, Fair Value
Less Than 12 Months	$ 4,907	$ 4,926
12 Months or More	399,567	437,710
Total	404,474	442,636
Less Than 12 Months	9,246	9,790
12 Months or More	520,555	533,766
Total	529,801	543,556
Securities, Unrealized (Losses)
Less Than 12 Months	(65)	(40)
12 Months or More	(9,614)	(9,894)
Total	(9,679)	(9,934)
Less Than 12 Months	(147)	(176)
12 Months or More	(93,340)	(86,559)
Total	(93,487)	(86,735)
U.S. Treasury
Securities, Fair Value
Less Than 12 Months	4,907	4,926
12 Months or More	342,546	377,443
Total	347,453	382,369
Securities, Unrealized (Losses)
Less Than 12 Months	(65)	(40)
12 Months or More	(4,719)	(5,581)
Total	(4,784)	(5,621)
Agency mortgage-backed securities
Securities, Fair Value
12 Months or More	57,021	60,267
Total	57,021	60,267
12 Months or More	500,329	520,615
Total	500,329	520,615
Securities, Unrealized (Losses)
12 Months or More	(4,895)	(4,313)
Total	(4,895)	(4,313)
12 Months or More	(92,415)	(86,011)
Total	(92,415)	(86,011)
Municipals - exempt from Federal tax
Securities, Fair Value
Less Than 12 Months	9,246	9,790
12 Months or More	20,226	13,151
Total	29,472	22,941
Securities, Unrealized (Losses)
Less Than 12 Months	(147)	(176)
12 Months or More	(925)	(548)
Total	$ (1,072)	$ (724)