Common 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	ESOP	Treasury stock	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2011	$ 523	$ 13,774	$ 12,490	$ (1,266)	$ (2,210)	$ (67)	$ 23,244
Balance (shares) at Dec. 31, 2011	2,614,506
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			320				320
Retirement benefits adjustment						(18)	(18)
Compensation expense				101			101
Purchase of treasury shares					(110)		(110)
Cash dividend			(716)				(716)
Exercise of stock options, net of tax benefit		213	(323)		555		445
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						2,614,506
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			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