Pension And Other Postretirement Benefits (Summary Of Plan Assets By Level) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 136,905	$ 138,423
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,426	137,026
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,078
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,401	1,397	1,326
Common Collective Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,078
Common Collective Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,078
Exchange Traded Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,415	136,485
Exchange Traded Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,415	136,485
Money Market Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11	541
Money Market Mutual Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11	541
Insurance Company Investment Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,401	1,397
Insurance Company Investment Contract [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,401	$ 1,397