Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($)	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Preferred Stock [Member]	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balances (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2021	$ 316,000	$ 316,000
Balances at Dec. 31, 2021			$ 0	$ 285,752,000	$ 174,536,000	$ (3,729,000)	$ 456,559,000
Employee stock purchase plan				21,000			21,000
Dividend reinvestment plan				435,000			435,000
Stock grants to directors for retainer fees				347,000			347,000
Stock-based compensation expense				1,608,000			1,608,000
Cash dividends					(9,629,000)		(9,629,000)
Net income					23,229,000		23,229,000
Change in net unrealized holding gain (loss) on securities available for sale, net of tax effect						(43,939,000)	(43,939,000)
Stock option exercises				36,000			36,000
Balances at Jun. 30, 2022			0	288,199,000	188,452,000	(47,668,000)	428,983,000
Balances at Mar. 31, 2022			0	286,831,000	181,532,000	(31,892,000)	436,471,000
Employee stock purchase plan				11,000			11,000
Dividend reinvestment plan				213,000			213,000
Stock grants to directors for retainer fees				347,000			347,000
Stock-based compensation expense				797,000			797,000
Cash dividends					(4,817,000)		(4,817,000)
Net income					11,737,000		11,737,000
Change in net unrealized holding gain (loss) on securities available for sale, net of tax effect						(15,776,000)	(15,776,000)
Balances at Jun. 30, 2022			0	288,199,000	188,452,000	(47,668,000)	428,983,000
Balances at Dec. 31, 2022			0	290,436,000	216,313,000	(65,341,000)	441,408,000
Employee stock purchase plan				23,000			23,000
Dividend reinvestment plan				449,000			449,000
Stock grants to directors for retainer fees				317,000			317,000
Stock-based compensation expense				1,681,000			1,681,000
Cash dividends					(10,332,000)		(10,332,000)
Net income					41,332,000		41,332,000
Change in net unrealized holding gain (loss) on securities available for sale, net of tax effect						3,824,000	3,824,000
Balances at Jun. 30, 2023			0	292,906,000	247,313,000	(61,517,000)	478,702,000
Balances at Mar. 31, 2023			0	291,516,000	232,123,000	(56,267,000)	467,372,000
Employee stock purchase plan				13,000			13,000
Dividend reinvestment plan				232,000			232,000
Stock grants to directors for retainer fees				317,000			317,000
Stock-based compensation expense				828,000			828,000
Cash dividends					(5,167,000)		(5,167,000)
Net income					20,357,000		20,357,000
Change in net unrealized holding gain (loss) on securities available for sale, net of tax effect						(5,250,000)	(5,250,000)
Balances at Jun. 30, 2023			$ 0	$ 292,906,000	$ 247,313,000	$ (61,517,000)	$ 478,702,000