Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Schedule of Estimated Future Beneffit Payments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
2012	$ 29,597
2013	29,491
2014	29,235
2015	29,110
2016	28,936
2017 through 2021	143,053
Other Postretirement Benefit Plans, Defined Benefit [Member]
2012	6,460
2013	5,974
2014	5,610
2015	5,346
2016	5,067
2017 through 2021	$ 20,132

The amount of the aggregate benefits expected to be paid in the five fiscal years thereafter (the aggregate amount of benefits expected to be paid in years 6 through 10 after the date of the latest statement of financial position).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant