Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Shares issued using employee stock purchase plan	2,400	4,726
Shares issued using stock option exercises	50,930	8,800	0
Common Stock
Shares issued using employee stock purchase plan	2,400	4,726	9,129
Shares issued using stock option exercises	50,930	8,800
Number of shares tendered for stock option exercises	19,120
Shares issued using dividend reinvestment plan	934	644	687
Cash dividends per share	0.09		0.01