Stock Benefit Plan (Schedule Of Weighted Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	4.32%	5.87%	6.93%
Expected volatility	25.98%	19.31%	31.33%
Risk free interest rate	2.36%	2.75%	2.46%
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected lives, in years	6.0	5.7	5.7
Non-Employee Director Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected lives, in years		6.7	4.9