Shareholders' Equity - Summary of common shareholders' equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	Common stock	Capital in excess of par value	Retained earnings	ESOT	Treasury stock	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2012	$ 523	$ 13,987	$ 11,771	$ (1,165)	$ (1,765)	$ (85)	$ 23,266
Balance (shares) at Dec. 31, 2012	2,614,506
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)			975				975
Retirement benefits adjustment						59	59
Compensation expense				100			100
Purchase of treasury shares					(607)		(607)
Stock based compensation		16			239		255
Cash dividend			(406)				(406)
Exercise of stock options, net of tax benefit		21	(38)		109		92
Balance at Dec. 31, 2013	523	14,024	12,302	(1,065)	(2,024)	(26)	23,734
Balance (shares) at Dec. 31, 2013	2,614,506						2,614,506
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)			(3,126)				(3,126)
Retirement benefits adjustment						12	12
Compensation expense				101			101
Purchase of treasury shares					(202)		(202)
Stock based compensation		44			317		361
Balance at Dec. 31, 2014	$ 523	$ 14,068	$ 9,176	$ (964)	$ (1,909)	$ (14)	$ 20,880
Balance (shares) at Dec. 31, 2014	2,614,506						2,614,506