Anticipated debt issuance amount of future debt issuance.

No definition available.

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- Definition

Gain or loss recognized in earnings during the reporting period representing the amount of the hedges' ineffectiveness for fair value and cash flow hedges.

+ References

No definition available.

+ Details

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- Definition

Actual percentage of heating season gas purchases hedged using financial instruments.

+ References

No definition available.

+ Details

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- Definition

Actual volume of heating season gas purchases hedged using financial instruments.

+ References

No definition available.

+ Details

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- Definition

Maximum anticipated percentage of heating season gas purchases hedged using financial instruments.

+ References

No definition available.

+ Details

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- Definition

Minimum anticipated percentage of heating season gas purchases hedged using financial instruments.

+ References

No definition available.

+ Details

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- Definition

Minimum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Derivative instruments where an offsetting derivative position does not exist leading to an exposure to possible losses.

+ References

No definition available.

+ Details

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- Definition

The domestic federal statutory tax rate applicable under enacted tax laws to the Nonregulated operations pretax income from continuing operations for the period. The "statutory" tax rate shall be the regular tax rate if there are alternative tax systems.

+ References

No definition available.

+ Details

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- Definition

The domestic federal statutory tax rate applicable under enacted tax laws to the Regulated operations pretax income from continuing operations for the period. The "statutory" tax rate shall be the regular tax rate if there are alternative tax systems.

+ References

No definition available.

+ Details

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- Definition

Weighted average cost of heating season gas purchased using financial instruments.

+ References

No definition available.

+ Details

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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- Definition

The amount of cash received during the period on settlement of a hedge.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

+ 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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- References

No definition available.

+ Details

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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- Details

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Financial Instruments Descriptions (Details) $ in Millions	1 Months Ended	12 Months Ended
Financial Instruments Descriptions (Details) $ in Millions	Oct. 31, 2014 USD ($)	Sep. 30, 2016 USD ($) $ / Mcf MMcf	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Minimum Hedge Percentage Of Anticipated Heating Season Gas		25.00%
Maximum Hedge Percentage Of Anticipated Heating Season Gas		50.00%
Hedge Percentage Of Actual Heating Season Gas		33.00%
Hedge Volume Of Actual Heating Season Gas \| MMcf		23,000
Weighted Average Cost Of Actual Heating Season Gas \| $ / Mcf		3.14
Minimum Length Of Time Hedged In Cash Flow Hedge		1 month
Maximum Length of Time Hedged in Cash Flow Hedge		63 months
Net Open Positions \| MMcf		100
Gain (Loss) On Hedge Ineffectiveness		$ 21.6	$ 0.2	$ 1.9
Regulated Segments Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate		37.00%	37.00%
Nonregulated Segment Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate		39.00%	39.00%
Gain (Loss) On Derivative Instruments Not Designated Hedges Net Pretax		$ (15.5)	$ 15.5	$ (5.0)
Interest Rate Hedges, Senior Notes 2015 Issuance [Member]
Derivative [Line Items]
Derivative, Notional Amount		500.0
Derivative, Cash Received on Hedge	$ 13.4
Interest Rate Hedges, Senior Notes 2017 Issuance [Member]
Derivative [Line Items]
Derivative, Notional Amount		210.0
Anticipated Debt Issuance, Amount		250.0
Interest Rate Hedges, Senior Notes 2019 Issuance [Member]
Derivative [Line Items]
Derivative, Notional Amount		450.0
Anticipated Debt Issuance, Amount		$ 450.0