CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE LOSS	TREASURY STOCK
Beginning Balance (in shares) at Dec. 31, 2014		5,002,649
Beginning Balance at Dec. 31, 2014	$ 135,967	$ 41,688	$ 49,896	$ 53,107	$ (1,667)	$ (7,057)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,152			10,152
Other comprehensive loss	(1,433)				(1,433)
Dividends declared	(6,736)			(6,736)
Common shares issued for employee stock purchase plan (in shares)		1,723
Common shares issued for employee stock purchase plan	77	$ 14	63
Purchase of treasury stock	(2,450)					(2,450)
Ending Balance (in shares) at Sep. 30, 2015		5,004,372
Ending Balance at Sep. 30, 2015	135,577	$ 41,702	49,959	56,523	(3,100)	(9,507)
Beginning Balance (in shares) at Dec. 31, 2015		5,004,984
Beginning Balance at Dec. 31, 2015	136,279	$ 41,708	49,992	58,038	(3,799)	(9,660)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,529			9,529
Other comprehensive loss	1,308				1,308
Dividends declared	(6,678)			(6,678)
Common shares issued for employee stock purchase plan (in shares)		1,617
Common shares issued for employee stock purchase plan	71	$ 13	58
Purchase of treasury stock	(574)					(574)
Ending Balance (in shares) at Sep. 30, 2016		5,006,601
Ending Balance at Sep. 30, 2016	$ 139,935	$ 41,721	$ 50,050	$ 60,889	$ (2,491)	$ (10,234)