Retirement Plans (Details 2)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Assumed health care cost trend rates for other postretirement benefits
Pre-65	2020	2020
Post-65	2018	2018
Other Postretirement Benefits [Member]
Assumed health care cost trend rates for other postretirement benefits
Pre-65 health care cost trend rate assumed for next year	9.00%	9.50%
Post-65 health care cost trend rate assumed for next year	8.00%	8.50%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%

The ultimate trend rate for health care costs.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph l

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (l)

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

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