Postretirement Benefits (Net Periodic Benefit Costs Assumptions) (Details) (Postretirement Benefits [Member])	12 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.29%	5.21%	6.34%
Health care cost trend rate	10.00%	10.00%	10.00%

The interest rate used to adjust for the time value of money.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph j

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (k)(1)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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