Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2017	$ 4,689	$ 40,396	$ 82,218	$ (6,028)	$ (6,131)	$ 115,144
Cumulative adjustment for fair value of equity securities			201	(201)
Net income (loss)			(1,679)			(1,679)
Other comprehensive income (loss)				(1,053)		(1,053)
Cash dividends declared			(2,226)			(2,226)
Acquisition of treasury stock					(88)	(88)
Treasury shares issued under employee stock purchase plan		29			47	76
Treasury shares issued under dividend reinvestment plan		303			333	636
Common stock issued under incentive stock option plan	11	228				239
Stock option compensation expense		123				123
Balance at Jun. 30, 2018	4,700	41,079	78,514	(7,282)	(5,839)	111,172
Balance at Mar. 31, 2018	4,696	40,668	84,876	(7,010)	(6,106)	117,124
Net income (loss)			(5,181)			(5,181)
Other comprehensive income (loss)				(272)		(272)
Cash dividends declared			(1,181)			(1,181)
Treasury shares issued under employee stock purchase plan		27			43	70
Treasury shares issued under dividend reinvestment plan		207			224	431
Common stock issued under incentive stock option plan	4	84				88
Stock option compensation expense		93				93
Balance at Jun. 30, 2018	4,700	41,079	78,514	(7,282)	(5,839)	111,172
Balance at Dec. 31, 2018	4,701	41,530	83,946	(6,380)	(5,401)	118,396
Net income (loss)			7,221			7,221
Other comprehensive income (loss)				1,882		1,882
Cash dividends declared			(2,509)			(2,509)
Acquisition of treasury stock					(2,027)	(2,027)
Treasury shares issued under employee stock purchase plan		27			47	74
Treasury shares issued under dividend reinvestment plan		335			387	722
Common stock issued under incentive stock option plan	7	148				155
Balance at Jun. 30, 2019	4,708	42,040	88,658	(4,498)	(6,994)	123,914
Balance at Mar. 31, 2019	4,708	41,841	85,991	(5,281)	(5,768)	121,491
Net income (loss)			3,984			3,984
Other comprehensive income (loss)				783		783
Cash dividends declared			(1,317)			(1,317)
Acquisition of treasury stock					(1,467)	(1,467)
Treasury shares issued under employee stock purchase plan		25			44	69
Treasury shares issued under dividend reinvestment plan		174			197	371
Balance at Jun. 30, 2019	$ 4,708	$ 42,040	$ 88,658	$ (4,498)	$ (6,994)	$ 123,914