Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Dec. 31, 2014	$ 10,000	$ 936	$ 51,344	$ 105,774	$ 4,875	$ 172,929
Balance (in shares) at Dec. 31, 2014		7,489,000
Net income				14,992		14,992
Other comprehensive loss					(2,093)	(2,093)
Cash dividends declared – preferred				(395)		(395)
Redemption of preferred stock	(10,000)					(10,000)
Redemption of preferred stock (in shares)
Shares issued under director compensation plan			104			104
Shares issued under director compensation plan (in shares)		4,000
Shares issued pursuant to employee stock purchase plan		$ 1	129			$ 130
Shares issued pursuant to employee stock purchase plan (in shares)		7,000				6,329
Expense related to employee stock purchase plan			31			$ 31
Balance at Dec. 31, 2015		$ 937	51,608	120,371	2,782	175,698
Balance (in shares) at Dec. 31, 2015		7,500,000
Net income				16,605		16,605
Other comprehensive loss					(6,190)	(6,190)
Shares issued under director compensation plan		$ 1	91			92
Shares issued under director compensation plan (in shares)		3,000
Shares issued pursuant to employee stock purchase plan		$ 1	154			$ 155
Shares issued pursuant to employee stock purchase plan (in shares)		6,000				6,631
Expense related to employee stock purchase plan			32			$ 32
Cash dividends declared – common				(2,326)		(2,326)
Adoption of Accounting Standards Update 2018-02
Balance at Dec. 31, 2016		$ 939	51,885	134,650	(3,408)	184,066
Balance (in shares) at Dec. 31, 2016		7,509,000
Net income				11,688		11,688
Other comprehensive loss					475	475
Shares issued under director compensation plan			105			105
Shares issued under director compensation plan (in shares)		3,000
Shares issued pursuant to employee stock purchase plan		$ 1	178			$ 179
Shares issued pursuant to employee stock purchase plan (in shares)		5,000				5,367
Expense related to employee stock purchase plan			33			$ 33
Cash dividends declared – common				(3,193)		(3,193)
Adoption of Accounting Standards Update 2018-02				633	(633)
Balance at Dec. 31, 2017		$ 940	$ 52,201	$ 143,778	$ (3,566)	$ 193,353
Balance (in shares) at Dec. 31, 2017		7,517,000