Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2016	$ 0	$ 21,067	$ 106,102	$ 28,909	$ (1,121)	$ 0	$ 154,957
Net income				3,419			3,419
Other comprehensive income (loss), net of tax					450		450
Cash dividends				(1,138)			(1,138)
Stock-based compensation			133				133
Issuance and reissuance of common stock:
Issuance of shares under the dividend reinvestment and stock purchase plan		11	107				118
Issuance of shares of stock-based compensation awards		6	(6)				0
Balance at Mar. 31, 2017	0	21,084	106,336	31,190	(671)	0	157,939
Balance at Dec. 31, 2017	0	22,265	120,052	22,860	(958)	0	164,219
Net income				4,083			4,083
Other comprehensive income (loss), net of tax					(1,788)		(1,788)
Cash dividends				(1,381)			(1,381)
Stock-based compensation			230				230
Forfeiture of restricted stock and withheld shares						(63)	(63)
Issuance and reissuance of common stock:
Issuance of shares under the dividend reinvestment and stock purchase plan		9	76			57	142
Issuance of shares under the stock option plan		34	205				239
Issuance of shares of stock-based compensation awards		5	(5)				0
Balance at Mar. 31, 2018	$ 0	$ 22,313	$ 120,558	$ 25,562	$ (2,746)	$ (6)	$ 165,681