Pension Plans and Other Postretirement Employee Benefits (Narrative) (Details) (USD $) In Millions	3 Months Ended	9 Months Ended
Mar. 31, 2011 Discretionary Funding [Member]	Mar. 31, 2011 Qualified Salaried Pension Plan [Member]	Mar. 31, 2011 Qualified Non-Represented Pension Plan [Member]	Sep. 30, 2011 Non-Qualified Supplemental Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 5.8	$ 5.0	$ 4.4	$ 1.3

The increase in the fair value of plan assets from contributions made by the employer.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (b)(3)

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

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration