Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]
Stock option exercises	108,800	114,293
Purchase of treasury stock, shares		3,464
Common stock issued/sold to the 401( k) stock purchase plan, shares		22,680
Cash dividends, per share	$ 0.46	$ 0.45