Pension And Postretirement Obligations (Schedule Of Fair Value Of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Pension Benefits [Member]
Plan assets	$ 12,443		$ 11,265		$ 11,690
Pension Benefits [Member] | Equity Securities [Member]
Plan assets	6,239	[1]	5,826	[1]
Pension Benefits [Member] | Fixed Income Securities [Member]
Plan assets	5,390	[2]	4,605	[2]
Pension Benefits [Member] | Cash And Cash Equivalents [Member]
Plan assets	814	[3]	834	[3]
Pension Benefits [Member] | Level 1 [Member]
Plan assets	12,443		11,265
Pension Benefits [Member] | Level 1 [Member] | Equity Securities [Member]
Plan assets	6,239	[1]	5,826	[1]
Pension Benefits [Member] | Level 1 [Member] | Fixed Income Securities [Member]
Plan assets	5,390	[2]	4,605	[2]
Pension Benefits [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member]
Plan assets	814	[3]	834	[3]
Postretirement Benefits [Member]
Plan assets	2,221		2,167		2,096
Postretirement Benefits [Member] | Fixed Income Securities [Member]
Plan assets	1,760	[2]	1,706	[2]
Postretirement Benefits [Member] | Cash And Cash Equivalents [Member]
Plan assets	461	[3]	461	[3]
Postretirement Benefits [Member] | Level 1 [Member]
Plan assets	2,221		2,167
Postretirement Benefits [Member] | Level 1 [Member] | Fixed Income Securities [Member]
Plan assets	1,760	[2]	1,706	[2]
Postretirement Benefits [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member]
Plan assets	$ 461	[3]	$ 461	[3]

[1] This category includes funds invested in equity securities of large, medium and small-sized companies and equity securities of international markets. The funds are valued using the market value for the underlying investments.

[2] This category includes funds invested in fixed income instruments. The funds are valued using the market value for the underlying investments.

[3] This category comprises cash held to pay beneficiaries. The fair value equals its book value.