CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 31, 2018	$ 133,248	$ 87,333	$ (3,852)	$ 216,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	18,302	0	18,302
Other comprehensive income (loss)	0	0	7,933	7,933
Cash dividends paid	0	(6,588)	0	(6,588)
Stock options exercised	176	0	0	176
Stock based compensation expense	256	0	0	256
Balances at Sep. 30, 2019	133,680	99,047	4,081	236,808
Balances at Jun. 30, 2019	133,597	94,978	3,727	232,302
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	6,267	0	6,267
Other comprehensive income (loss)	0	0	354	354
Cash dividends paid	0	(2,198)	0	(2,198)
Stock options exercised	36	0	0	36
Stock based compensation expense	47	0	0	47
Balances at Sep. 30, 2019	133,680	99,047	4,081	236,808
Balances at Dec. 31, 2019	133,795	102,743	3,703	240,241
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	16,498	0	16,498
Other comprehensive income (loss)	0	0	5,820	5,820
Cash dividends paid	0	(6,602)	0	(6,602)
Stock options exercised	31	0	0	31
Stock based compensation expense	253	0	0	253
Balances at Sep. 30, 2020	134,079	112,639	9,523	256,241
Balances at Jun. 30, 2020	134,052	109,216	10,727	253,995
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	5,624	0	5,624
Other comprehensive income (loss)	0	0	(1,204)	(1,204)
Cash dividends paid	0	(2,201)	0	(2,201)
Stock options exercised	0	0	0	0
Stock based compensation expense	27	0	0	27
Balances at Sep. 30, 2020	$ 134,079	$ 112,639	$ 9,523	$ 256,241