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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, PENSION AND POSTEMPLOYMENT PLANS (Details) $ in Thousands | 12 Months Ended
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Sep. 30, 2015 USD ($) plan | Sep. 30, 2014 USD ($) | Sep. 30, 2013 USD ($)
Defined Benefit Plan Disclosure [Line Items] |  |  |
Number of noncontributory defined benefit retirement plans | 2 |  |
Number of noncontributory medical and life insurance plans | 2 |  |
OPEB [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Employer contributions | $ | $ 5,672 | $ 4,970 | $ 6,000

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- Definition The increase in the fair value of plan assets from contributions made by the employer. + References Reference 1: 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=58740216&loc=d3e1928-114920 + Details
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