Common Shareholders' Equity (Detail Textuals) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Share Repurchase Program	Oct. 31, 2008 Share Repurchase Program	Jan. 31, 2006 Share Repurchase Program	Feb. 28, 2013 Share Repurchase Program Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be purchased (in shares)					250,000
Remaining number of shares authorized to be purchased (in shares)				200,000		186,188
Number of shares purchased under purchase program (in shares)						263,812
Treasury stock, shares (in shares)	241,372	305,135	13,737
Purchase of treasury shares	$ 110		$ 110