CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance at Dec. 31, 2019	$ 275	$ 190,524	$ 134,287	$ 7,832		$ 332,918
Balance (in shares) at Dec. 31, 2019	27,457,306
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			6,221			6,221
Other comprehensive income (loss)				4,737		4,737
Stock-based compensation		67				67
Cash dividends and dividend equivalents			(4,130)			(4,130)
Balance at Mar. 31, 2020	$ 275	190,591	136,378	12,569		339,813
Balance (in shares) at Mar. 31, 2020	27,457,306
Balance at Dec. 31, 2020	$ 275	190,875	154,614	18,153		363,917
Balance (in shares) at Dec. 31, 2020	27,457,306
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			15,245			15,245
Other comprehensive income (loss)				(16,247)		(16,247)
Stock-based compensation		129				129
Issuance of common stock upon vesting of restricted stock units (in shares)	20,225
Repurchase of common stock					$ (1,514)	(1,514)
Repurchase of common stock (in shares)	(95,462)
Cash dividends and dividend equivalents			(4,124)			(4,124)
Balance at Mar. 31, 2021	$ 275	$ 191,004	$ 165,735	$ 1,906	$ (1,514)	$ 357,406
Balance (in shares) at Mar. 31, 2021	27,382,069