Shareholders' Equity - Summary of 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, 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			177				177
Purchase of treasury shares					(144)		(144)
Exercise of stock options, net of tax benefit		21	(39)		109		91
Balance at Mar. 31, 2013	$ 523	$ 14,008	$ 11,909	$ (1,165)	$ (1,800)	$ (85)	$ 23,390
Balance (shares) at Mar. 31, 2013	2,614,506						2,614,506