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) Income [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2016	$ 21,067	$ 106,102	$ 28,909	$ (1,121)	$ 0	$ 154,957
Net income			12,004			12,004
Impact of change in enacted tax rate			170	(170)		0
Other comprehensive income, net of tax				333		333
Common stock cash dividends			(4,559)			(4,559)
5% common stock dividend, at fair value		12,510
5% common stock dividend, at fair value	1,049		(13,664)		86	(19)
Stock-based compensation		752				752
Forfeiture and withheld shares of restricted stock		4			(163)	(159)
Issuance and reissuance of stock:
Issuance of shares under the dividend reinvestment and stock purchase plan	40	403			22	465
Issuance of shares under the stock option plan	28	153			14	195
Issuance of shares of stock-based compensation awards	61	(61)				0
Issuance of shares under employee stock purchase plan	20	189			41	250
Balance at Dec. 31, 2017	22,265	120,052	22,860	(958)	0	164,219
Net income			19,542			19,542
Other comprehensive income, net of tax				(1,268)		(1,268)
Common stock cash dividends			(5,539)			(5,539)
5% common stock dividend, at fair value		12,889
5% common stock dividend, at fair value	1,118		(14,026)			(19)
Stock-based compensation		697				697
Forfeiture and withheld shares of restricted stock		5			(158)	(153)
Issuance and reissuance of stock:
Issuance of shares under the dividend reinvestment and stock purchase plan	44	445			57	546
Issuance of shares under the stock option plan	110	319			76	505
Issuance of shares of stock-based compensation awards	72	(72)				0
Issuance of shares under employee stock purchase plan	20	171			25	216
Balance at Dec. 31, 2018	23,629	134,506	22,837	(2,226)	0	178,746
Adoption of ASC topic 842 (leases)			(199)			(199)
Net income			18,647			18,647
Other comprehensive income, net of tax				3,535		3,535
Common stock cash dividends			(6,017)			(6,017)
5% common stock dividend, at fair value		5,049
5% common stock dividend, at fair value	656		(10,249)		4,531	(13)
Stock-based compensation		666				666
Forfeiture and withheld shares of restricted stock		7			(95)	(88)
Repurchased stock					(4,993)	(4,993)
Issuance and reissuance of stock:
Issuance of shares under the dividend reinvestment and stock purchase plan	42	393			145	580
Issuance of shares under the stock option plan		(160)			219	59
Issuance of shares of stock-based compensation awards	51	(65)			14	0
Issuance of shares under employee stock purchase plan	12	54			179	245
Balance at Dec. 31, 2019	$ 24,390	$ 140,450	$ 25,019	$ 1,309	$ 0	$ 191,168