Common Stock (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Class of Stock [Line Items]
Common stock issued in acquisition (in shares)			179,036
Common stock, par value (in dollars per share)	$ 1		$ 1		$ 1
Common stock dividend rate percentage (in hundredths)	10.00%
Dividends payable record date	Feb. 17, 2012
Dividends payable date to be paid	Feb. 24, 2012
Shares outstanding at beginning of year (in shares)	5,722,408	[1]	5,559,644	[1]	5,559,644	[1]	5,559,644	[1]
Shares issued in acquisition (unadjusted for stock dividend) (in shares)	0		162,764	[1]	0	[1]	0	[1]
Shares outstanding prior to stock dividend (in shares)	5,722,408		5,722,408	[1]	5,559,644	[1]	5,559,644	[1]
Shares issued in stock dividend (includes dividend on acquisition shares) (in shares)	571,819	[1]	571,819		555,964		555,964	[1]
Treasury shares purchased (in shares)	(2,895)		0	[1]	0	[1]	0	[1]
Total $1 par common shares outstanding (in shares)	6,291,332		6,294,227	[1]	6,115,608	[1]	6,115,608	[1]
Greensburg Bancshares, Inc [Member]
Class of Stock [Line Items]
Common stock issued in acquisition (in shares)			179,036
Common stock, par value (in dollars per share)			$ 1

[1] The shares issued as a stock dividend were estimated for the years 2010 and 2009. The estimate was based on ten percent of the aggregate shares outstanding at the respective balance sheet dates.