Benefit Plans (Details 4) (USD $) In Thousands	Sep. 30, 2011
Pension Plans [Member]
Expected benefit payments
2012	$ 128,921
2013	96,178
2014	101,061
2015	111,483
2016	116,066
2017-2021	735,367
Other Postretirement Benefit [Member]
Expected benefit payments
2012	18,188
2013	18,708
2014	19,224
2015	19,778
2016	20,199
2017-2021	$ 102,714

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant