Stock-Based Compensation (Summary Of Stock Options Outstanding) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	3
Exercisable Options Outstanding	927,025	2,935,250
Weighted Average Exercise Price	$ 43.046	$ 43.588
2006 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	4
Exercisable Options Outstanding	323,950
Weighted Average Exercise Price	$ 44.178
2005 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	3
Exercisable Options Outstanding	239,975
Weighted Average Exercise Price	$ 42.328
2004 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	2
Exercisable Options Outstanding	216,600
Weighted Average Exercise Price	$ 44.018
2003 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	1
Exercisable Options Outstanding	82,450
Weighted Average Exercise Price	$ 38.555
2002 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining Contractual Life	1
Exercisable Options Outstanding	64,050
Weighted Average Exercise Price	$ 42.510