Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]
Options exercised, shares	136,290	263,206	0
Conversion of common stock units, shares	15,715	160,876	84,562
Conversion of restricted stock units, shares	182,309	47,149	38,371
Cash dividends, per share	$ 0.46	$ 0.35	$ 0.2375
Treasury stock, beginning balance, shares	21,813,196	21,813,196	21,813,196
Treasury stock, acquisition of shares	214,834	0	0
Treasury stock, ending balance, shares	22,028,030	21,813,196	21,813,196