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Benefit Plans Postretirement Benefit Costs Deferred as Regulatory Assets (Details) - USD ($) $ in Millions | Sep. 30, 2015 | Sep. 30, 2014
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Defined Benefit Plan Disclosure |  |
Regulatory assets | $ 10,418 | $ 8,994
Pension Benefits |  |
Defined Benefit Plan Disclosure |  |
Unrecognized prior service cost (credit) | (158) | (180)
Unrecognized net loss | 5,355 | 4,337
Amount capitalized due to actions of regulator | (228) | 0
Regulatory assets | 5,425 | 4,157
Other Post-retirement Benefits |  |
Defined Benefit Plan Disclosure |  |
Unrecognized prior service cost (credit) | (33) | (39)
Unrecognized net loss | 173 | 179
Amount capitalized due to actions of regulator | 0 | 0
Regulatory assets | $ 140 | $ 140

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- Definition Amount deferred as regulatory asset of gains and losses that are not yet recognized as a component of net periodic benefit cost. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan. + References No definition available. + Details
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- Definition Deferred amount in regulatory assets related to the cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost. + References No definition available. + Details
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- Definition Defined benefit plan amounts deferred as regulatory assets due to actions by regulators + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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- Details
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