Pension Plans And Other Postretirement Benefit Plans (Schedule Of Allocation Of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Common/Collective Trusts [Member] | Absolute Return [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 0		$ 95
Common/Collective Trusts [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,596	8,598		423
Partnership And Closely Held Investments [Member] | Absolute Return [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,755	16,587		16,917
Partnership And Closely Held Investments [Member] | Private Equity Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	660	808		1,272
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	406,061	328,150		306,712
Pension Benefits [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	326,943	254,164
Pension Benefits [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43,107	47,993
Pension Benefits [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36,011	25,993
Pension Benefits [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		7,550
Pension Benefits [Member] | Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Pension Benefits [Member] | Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		7,550
Pension Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	83,037	76,486
Pension Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	83,037	76,486
Pension Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135,436	102,790
Pension Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135,436	102,790
Pension Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	79,448	52,241
Pension Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	79,448	52,241
Pension Benefits [Member] | Mutual Funds [Member] | Absolute Return [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20,764	16,121	[1]
Pension Benefits [Member] | Mutual Funds [Member] | Absolute Return [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20,764	16,121	[1]
Pension Benefits [Member] | Mutual Funds [Member] | Commodities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,258	6,526	[2]
Pension Benefits [Member] | Mutual Funds [Member] | Commodities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,258	6,526	[2]
Pension Benefits [Member] | Common/Collective Trusts [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43,107
Pension Benefits [Member] | Common/Collective Trusts [Member] | Fixed Income Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43,107
Pension Benefits [Member] | Common/Collective Trusts [Member] | U.S Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		27,774
Pension Benefits [Member] | Common/Collective Trusts [Member] | U.S Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		27,774
Pension Benefits [Member] | Common/Collective Trusts [Member] | Absolute Return [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		12,669
Pension Benefits [Member] | Common/Collective Trusts [Member] | Absolute Return [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		12,669
Pension Benefits [Member] | Common/Collective Trusts [Member] | Absolute Return [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Pension Benefits [Member] | Common/Collective Trusts [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,596	8,598
Pension Benefits [Member] | Common/Collective Trusts [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,596	8,598
Pension Benefits [Member] | Partnership And Closely Held Investments [Member] | Absolute Return [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,755	16,587	[1]
Pension Benefits [Member] | Partnership And Closely Held Investments [Member] | Absolute Return [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,755	16,587	[1]
Pension Benefits [Member] | Partnership And Closely Held Investments [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	660	808	[3]
Pension Benefits [Member] | Partnership And Closely Held Investments [Member] | Private Equity Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	660	808	[3]
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25,288	22,455		22,875
Other Post-Retirement Benefits [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25,282	22,369
Other Post-Retirement Benefits [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	86
Other Post-Retirement Benefits [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	86
Other Post-Retirement Benefits [Member] | Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	86
Other Post-Retirement Benefits [Member] | Cash Equivalents [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | U.S Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,569
Other Post-Retirement Benefits [Member] | U.S Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,569
Other Post-Retirement Benefits [Member] | U.S Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Other Post-Retirement Benefits [Member] | U.S Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Other Post-Retirement Benefits [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		73
Other Post-Retirement Benefits [Member] | Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		73
Other Post-Retirement Benefits [Member] | Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Other Post-Retirement Benefits [Member] | Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,314	8,683
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,314	8,683
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | Fixed Income Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,266	7,278
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,266	7,278
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | U.S Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,702	4,766
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,702	4,766
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Post-Retirement Benefits [Member] | Mutual Funds [Member] | International Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

[1] This category invests in multiple strategies to diversify risk and reduce volatility. The strategies include: (a) event driven, relative value, convertible, and fixed income arbitrage, (b) distressed investments, (c) long/short equity and fixed income, and (d) market neutral strategies.

[2] The fund primarily invests in derivatives linked to commodity indices to gain exposure to the commodity markets. The fund manager fully collateralizes these positions with debt securities.

[3] This category includes private equity funds that invest primarily in U.S. companies.