Stock Transactions (Assumptions Used In The Black-Scholes Model To Value Options Granted) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average volatility	28.00%	28.00%	31.00%
Dividend yield	0.20%	0.20%	0.20%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.17%	1.39%	2.08%
Expected years until exercise	6.0	6.0	6.0
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	3.19%	3.41%	3.68%
Expected years until exercise	8.5	8.5	9.5