Pension Plan (Schedule Of Market Values Of Pension Plan Assets) (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	$ 87,940	$ 73,402	$ 61,451
U.S. Large Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18,921	22,010
U.S. Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,281	1,468
U.S. Small-Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,332	6,295
U.S. Small Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,282	1,471
International Developed [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,692	10,353
Emerging Markets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,123	3,709
Core Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		11,542
Long Duration Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44,587	11,421
REIT Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,269	3,740
Cash Equivalents [Member] | Cash/Currency [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	453	1,393
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | U.S. Large Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | U.S. Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | U.S. Small-Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | U.S. Small Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | International Developed [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | Emerging Markets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | Core Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | Long Duration Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | REIT Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | Commodities [Member] | Tangible Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 1 [Member] | Cash Equivalents [Member] | Cash/Currency [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	87,940	73,402
Level 2 [Member] | U.S. Large Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18,921	22,010
Level 2 [Member] | U.S. Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,281	1,468
Level 2 [Member] | U.S. Small-Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,332	6,295
Level 2 [Member] | U.S. Small Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,282	1,471
Level 2 [Member] | International Developed [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,692	10,353
Level 2 [Member] | Emerging Markets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,123	3,709
Level 2 [Member] | Core Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		11,542
Level 2 [Member] | Long Duration Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44,587	11,421
Level 2 [Member] | REIT Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,269	3,740
Level 2 [Member] | Cash Equivalents [Member] | Cash/Currency [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	453	1,393
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | U.S. Large Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | U.S. Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | U.S. Small-Mid Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | U.S. Small Cap [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | International Developed [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Emerging Markets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Core Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Long Duration Fixed Income [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | REIT Fund [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Commodities [Member] | Tangible Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 3 [Member] | Cash Equivalents [Member] | Cash/Currency [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets