Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning Balance at Dec. 31, 2015	$ 24,795	$ 16,392	$ 55,151	$ (3,162)	$ 93,176
Beginning Balance (in shares) at Dec. 31, 2015	4,959,009
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	2,902	0	2,902
Total change in other comprehensive income or (loss), net of tax	0	0	0	1,877	1,877
Proceeds from exercise of stock options	$ 0	0	0	0	$ 0
Exercise of stock options (in shares)	0
Stock Issued During Period, Shares, Employee Stock Purchase Plans					0
Stock Repurchased and Retired During Period, Value	$ 0	0	0	0	$ 0
Stock Repurchased and Retired During Period, Shares	0
Cash dividends	$ 0	0	(1,488)	0	(1,488)
Ending Balance at Sep. 30, 2016	$ 24,795	16,392	56,565	(1,285)	96,467
Ending Balance (in shares) at Sep. 30, 2016	4,959,009
Beginning Balance at Dec. 31, 2016	$ 24,806	16,427	56,965	(4,208)	$ 93,990
Beginning Balance (in shares) at Dec. 31, 2016	4,961,258				4,961,258
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	2,860	0	$ 2,860
Total change in other comprehensive income or (loss), net of tax	0	0	0	1,521	1,521
Proceeds from exercise of stock options	$ 241	727	0	0	$ 968
Exercise of stock options (in shares)	48,287				(48,287)
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 13	58	0	0	$ 71
Stock Issued During Period, Shares, Employee Stock Purchase Plans	2,523				2,523
Stock Repurchased and Retired During Period, Value	$ (23)	(109)	0	0	$ (132)
Stock Repurchased and Retired During Period, Shares	(4,683)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures [Abstract]	$ 0	9	0	0	9
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures [Abstract]	0
Cash dividends	$ 0	0	(1,646)	0	(1,646)
Ending Balance at Sep. 30, 2017	$ 25,037	$ 17,112	$ 58,179	$ (2,687)	$ 97,641
Ending Balance (in shares) at Sep. 30, 2017	5,007,385				5,009,630