National Fuel Gas (NFG) 10-K 21 Nov 14 2014 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
	Sep. 30, 2014	Oct. 31, 2014	Mar. 31, 2014
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	30-Sep-14	'	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'FY	'	'
Entity Registrant Name	'NATIONAL FUEL GAS CO	'	'
Entity Central Index Key	'0000070145	'	'
Current Fiscal Year End Date	'--09-30	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	84,190,266	'
Entity Public Float	'	'	$5,688,675,000
Entity Current Reporting Status	'Yes	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'

Consolidated_Statements_Of_Inc

Consolidated Statements Of Income And Earnings Reinvested In The Business (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
INCOME	'	'	'
Operating Revenues	$2,113,081	$1,829,551	$1,626,853
Operating Expenses	'	'	'
Purchased Gas	605,838	460,432	415,589
Operation and Maintenance	463,078	442,090	401,397
Property, Franchise and Other Taxes	90,711	82,431	90,288
Depreciation, Depletion and Amortization	383,781	326,760	271,530
Total Operating Expenses	1,543,408	1,311,713	1,178,804
Operating Income	569,673	517,838	448,049
Other Income (Expense):	'	'	'
Other Income	9,461	4,697	5,133
Interest Income	4,170	4,335	3,689
Interest Expense on Long-Term Debt	-90,194	-90,273	-82,002
Other Interest Expense	-4,083	-3,838	-4,238
Income Before Income Taxes	489,027	432,759	370,631
Income Tax Expense	189,614	172,758	150,554
Net Income Available for Common Stock	299,413	260,001	220,077
EARNINGS REINVESTED IN THE BUSINESS	'	'	'
Balance at Beginning of Year	1,442,617	1,306,284	1,206,022
Beginning Retained Earnings Unappropriated And Current Period Net Income Loss	1,742,030	1,566,285	1,426,099
Dividends on Common Stock	-127,669	-123,668	-119,815
Balance at End of Year	$1,614,361	$1,442,617	$1,306,284
Earnings Per Common Share, Basic:	'	'	'
Net Income Available for Common Stock (in usd per share)	$3.57	$3.11	$2.65
Earnings Per Common Share, Diluted:	'	'	'
Net Income Available for Common Stock (in usd per share)	$3.52	$3.08	$2.63
Weighted Average Number of Shares Outstanding:	'	'	'
Used in Basic Calculation	83,929,989	83,518,857	83,127,844
Used in Diluted Calculation	84,952,347	84,341,220	83,739,771

Consolidated_Statements_Of_Com

Consolidated Statements Of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'
Net Income Available for Common Stock	$299,413	$260,001	$220,077
Other Comprehensive Income (Loss), Before Tax:	'	'	'
Increase (Decrease) in the Funded Status of the Pension and Other Post-Retirement Benefit Plans	-8,280	55,940	-27,552
Reclassification Adjustment for Amortization of Prior Year Funded Status of the Pension and Other Post-Retirement Benefit Plans	9,203	15,282	10,270
Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	3,863	5,041	3,545
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	5,334	91,790	-7,248
Reclassification Adjustment for Realized (Gains) Losses on Securities Available for Sale in Net Income	-662	0	0
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income	17,647	-36,029	-65,691
Other Comprehensive Income (Loss), Before Tax	27,105	132,024	-86,676
Income Tax Expense (Benefit) Related to the Increase (Decrease) in the Funded Status of the Pension and Other Post-Retirement Benefit Plans	-2,720	21,304	-10,144
Reclassification Adjustment for Income Tax Benefit Related to the Amortization of the Prior Year Funded Status of the Pension and Other Post-Retirement Benefit Plans	3,370	5,650	3,836
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	1,398	1,847	1,311
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	529	38,236	-8,244
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Securities Available for Sale in Net Income	-242	0	0
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) on Derivative Financial Instruments in Net Income	9,515	-14,799	-22,114
Income Taxes - Net	11,850	52,238	-35,355
Other Comprehensive Income (Loss)	15,255	79,786	-51,321
Comprehensive Income	$314,668	$339,787	$168,756

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2014		Sep. 30, 2013
In Thousands, unless otherwise specified
ASSETS	'		'
Property, Plant and Equipment	$8,245,791		$7,313,203
Less - Accumulated Depreciation, Depletion and Amortization	2,502,700		2,161,477
Property, Plant and Equipment, Net, Total	5,743,091		5,151,726
Current Assets	'		'
Cash and Temporary Cash Investments	36,886		64,858
Hedging Collateral Deposits	2,734	[1]	1,094	[1]
Receivables - Net of Allowance for Uncollectible Accounts of $31,811 and $27,144, Respectively	149,735		133,182
Unbilled Revenue	25,663		19,483
Gas Stored Underground	39,422		51,484
Materials and Supplies - at average cost	27,817		29,904
Unrecovered Purchased Gas Costs	0		12,408
Other Current Assets	54,752		56,905
Deferred Income Taxes	40,323		79,359
Total Current Assets	377,332		448,677
Other Assets	'		'
Recoverable Future Taxes	163,485		163,355
Unamortized Debt Expense	14,304		16,645
Other Regulatory Assets	224,436		252,568
Deferred Charges	14,212		9,382
Other Investments	86,788		96,308
Goodwill	5,476		5,476
Prepaid Post-Retirement Benefit Costs	36,512		22,774
Fair Value of Derivative Financial Instruments	72,606		48,989
Other	1,355		2,447
Total Other Assets	619,174		617,944
Total Assets	6,739,597		6,218,347
Capitalization:	'		'
Common Stock, $1 Par Value Authorized - 200,000,000 Shares; Issued and Outstanding - 84,157,220 Shares and 83,661,969 Shares, Respectively	84,157		83,662
Paid In Capital	716,144		687,684
Earnings Reinvested in the Business	1,614,361		1,442,617
Accumulated Other Comprehensive Loss	-3,979		-19,234
Total Comprehensive Shareholders' Equity	2,410,683		2,194,729
Long-Term Debt, Net of Current Portion	1,649,000		1,649,000
Total Capitalization	4,059,683		3,843,729
Current and Accrued Liabilities	'		'
Notes Payable to Banks and Commercial Paper	85,600		0
Current Portion of Long-Term Debt	0	[2]	0	[2]
Accounts Payable	136,674		105,283
Amounts Payable to Customers	33,745		12,828
Dividends Payable	32,400		31,373
Interest Payable on Long-Term Debt	29,960		29,960
Customer Advances	19,005		21,959
Customer Security Deposits	15,761		16,183
Other Accruals and Current Liabilities	136,672		83,946
Fair Value of Derivative Financial Instruments	759		639
Total Current and Accrued Liabilities	490,576		302,171
Deferred Credits	'		'
Deferred Income Taxes	1,456,283		1,347,007
Taxes Refundable to Customers	91,736		85,655
Unamortized Investment Tax Credit	1,145		1,579
Cost of Removal Regulatory Liability	173,199		157,622
Other Regulatory Liabilities	81,152		61,549
Pension and Other Post-Retirement Liabilities	134,202		158,014
Asset Retirement Obligations	117,713		119,511
Other Deferred Credits	133,908		141,510
Total Deferred Credits	2,189,338		2,072,447
Commitments and Contingencies	0		0
Total Capitalization and Liabilities	$6,739,597		$6,218,347
[1]	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.
[2]	None of the Company’s long-term debt at September 30, 2014 and 2013 will mature within the following twelve-month period.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Receivables, Allowance for Uncollectible Accounts	$31,811	$27,144
Common Stock, Par Value	$1	$1
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares Issued	84,157,220	83,661,969
Common Stock, Shares Outstanding	84,157,220	83,661,969

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Operating Activities	'	'	'
Net Income Available for Common Stock	$299,413	$260,001	$220,077
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:	'	'	'
Depreciation, Depletion and Amortization	383,781	326,760	271,530
Deferred Income Taxes	142,415	167,887	144,150
Excess Tax Benefits Associated with Stock-Based Compensation Awards	-4,641	-675	-985
Elimination of Other Post-Retirement Regulatory Liability	0	0	-21,672
Stock-Based Compensation	11,763	12,446	7,939
Other	14,063	14,965	5,013
Change in:	'	'	'
Hedging Collateral Deposits	-1,640	-730	19,337
Receivables and Unbilled Revenue	-22,781	-17,135	13,859
Gas Stored Underground and Materials and Supplies	13,285	-3,016	5,405
Unrecovered Purchased Gas Costs	12,408	-12,408	0
Other Current Assets	-3,630	-109	9,790
Accounts Payable	15,149	8,303	-16,773
Amounts Payable to Customers	20,917	-7,136	4,445
Customer Advances	-2,954	-2,096	4,412
Customer Security Deposits	-422	-1,759	621
Other Accruals and Current Liabilities	6,872	666	10,633
Other Assets	18,513	-5,757	-4,396
Other Liabilities	6,879	-1,635	-14,375
Net Cash Provided by Operating Activities	909,390	738,572	659,010
Investing Activities	'	'	'
Capital Expenditures	-914,417	-703,461	-1,035,007
Other	5,982	-2,522	446
Net Cash Used in Investing Activities	-908,435	-705,983	-1,034,561
Financing Activities	'	'	'
Change in Notes Payable to Banks and Commercial Paper	85,600	-171,000	131,000
Excess Tax Benefits Associated with Stock-Based Compensation Awards	4,641	675	985
Net Proceeds from Issuance of Long-Term Debt	0	495,415	496,085
Reduction of Long-Term Debt	0	-250,000	-150,000
Net Proceeds from Issuance of Common Stock	7,474	5,395	10,345
Dividends Paid on Common Stock	-126,642	-122,710	-118,798
Net Cash Provided By (Used in) Financing Activities	-28,927	-42,225	369,617
Net Decrease in Cash and Temporary Cash Investments	-27,972	-9,636	-5,934
Cash and Temporary Cash Investments At Beginning of Year	64,858	74,494	80,428
Cash and Temporary Cash Investments At End of Year	36,886	64,858	74,494
Supplemental Disclosure of Cash Flow Information	'	'	'
Cash Paid for Interest	91,927	91,215	79,820
Cash Paid for Income Taxes	40,944	13,187	474
Non-cash Capital Expenditures	$136,628	$81,138	$67,503

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies	12 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Summary Of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Principles of Consolidation
	The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to oil and gas producing properties accounted for under the full cost method of accounting.
	The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Regulation
	The Company is subject to regulation by certain state and federal authorities. The Company has accounting policies which conform to GAAP, as applied to regulated enterprises, and are in accordance with the accounting requirements and ratemaking practices of the regulatory authorities. Reference is made to Note C — Regulatory Matters for further discussion.
	Revenue Recognition
	The Company’s Exploration and Production segment records revenue based on entitlement, which means that revenue is recorded based on the actual amount of gas or oil that is delivered to a pipeline and the Company’s ownership interest in the producing well. If a production imbalance occurs between what was supposed to be delivered to a pipeline and what was actually produced and delivered, the Company accrues the difference as an imbalance.
	The Company’s Pipeline and Storage segment records revenue for natural gas transportation and storage services. Revenue from reservation charges on firm contracted capacity is recognized through equal monthly charges over the contract period regardless of the amount of gas that is transported or stored. Commodity charges on firm contracted capacity and interruptible contracts are recognized as revenue when physical deliveries of natural gas are made at the agreed upon delivery point or when gas is injected or withdrawn from the storage field. The point of delivery into the pipeline or injection or withdrawal from storage is the point at which ownership and risk of loss transfers to the buyer of such transportation and storage services.
	In the Company’s Gathering segment, revenue is recorded at the point at which gathered volumes are delivered into interstate pipelines.
	The Company’s Utility segment records revenue for gas sales and transportation in the period that gas is delivered to customers. This includes the recording of receivables for gas delivered but not yet billed to customers based on the Company's estimate of the amount of gas delivered between the last meter reading date and the end of the accounting period. Such receivables are a component of Unbilled Revenue on the Consolidated Balance Sheets.
	The Company’s Energy Marketing segment records revenue for gas sales in the period that gas is delivered to customers. This includes the recording of receivables for gas delivered but not yet billed to customers based on the Company's estimate of the amount of gas delivered between the last meter reading date and the end of the accounting period. Such receivables are a component of Unbilled Revenue on the Consolidated Balance Sheets.
	Allowance for Uncollectible Accounts
	The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is determined based on historical experience, the age and other specific information about customer accounts. Account balances are charged off against the allowance twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered.
	Regulatory Mechanisms
	The Company’s rate schedules in the Utility segment contain clauses that permit adjustment of revenues to reflect price changes from the cost of purchased gas included in base rates. Differences between amounts currently recoverable and actual adjustment clause revenues, as well as other price changes and pipeline and storage company refunds not yet includable in adjustment clause rates, are deferred and accounted for as either unrecovered purchased gas costs or amounts payable to customers. Such amounts are generally recovered from (or passed back to) customers during the following fiscal year.
	Estimated refund liabilities to ratepayers represent management’s current estimate of such refunds. Reference is made to Note C — Regulatory Matters for further discussion.
	The impact of weather on revenues in the Utility segment’s New York rate jurisdiction is tempered by a WNC, which covers the eight-month period from October through May. The WNC is designed to adjust the rates of retail customers to reflect the impact of deviations from normal weather. Weather that is warmer than normal results in a surcharge being added to customers’ current bills, while weather that is colder than normal results in a refund being credited to customers’ current bills. Since the Utility segment’s Pennsylvania rate jurisdiction does not have a WNC, weather variations have a direct impact on the Pennsylvania rate jurisdiction’s revenues.
	The impact of weather normalized usage per customer account in the Utility segment’s New York rate jurisdiction is tempered by a revenue decoupling mechanism. The effect of the revenue decoupling mechanism is to render the Company financially indifferent to throughput decreases resulting from conservation. Weather normalized usage per account that exceeds the average weather normalized usage per customer account results in a refund being credited to customers’ bills. Weather normalized usage per account that is below the average weather normalized usage per account results in a surcharge being added to customers’ bills. The surcharge or credit is calculated over a twelve-month period ending December 31st, and applied to customer bills annually, beginning March 1st.
	In the Pipeline and Storage segment, the allowed rates that Supply Corporation and Empire bill their customers are based on a straight fixed-variable rate design, which allows recovery of all fixed costs, including return on equity and income taxes, through fixed monthly reservation charges. Because of this rate design, changes in throughput due to weather variations do not have a significant impact on the revenues of Supply Corporation or Empire.
	Property, Plant and Equipment
	In the Company’s Exploration and Production segment, oil and gas property acquisition, exploration and development costs are capitalized under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of oil and gas properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and gas attributable to a cost center. For further discussion of capitalized costs, refer to Note M — Supplementary Information for Oil and Gas Producing Activities.
	Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying prices of oil and gas (as adjusted for hedging) to estimated future production of proved oil and gas reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unevaluated properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The natural gas and oil prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent impairment is required to be charged to earnings in that quarter. In adjusting estimated future net cash flows for hedging under the ceiling test at September 30, 2014, 2013, and 2012, estimated future net cash flows were decreased by $33.6 million and increased by $71.6 million and $128.4 million, respectively. At September 30, 2014, the ceiling exceeded the book value of the oil and gas properties by approximately $148.4 million.
	The principal assets of the Utility and Pipeline and Storage segments, consisting primarily of gas plant in service, are recorded at the historical cost when originally devoted to service.
	Maintenance and repairs of property and replacements of minor items of property are charged directly to maintenance expense. The original cost of the regulated subsidiaries’ property, plant and equipment retired, and the cost of removal less salvage, are charged to accumulated depreciation.
	Depreciation, Depletion and Amortization
	For oil and gas properties, depreciation, depletion and amortization is computed based on quantities produced in relation to proved reserves using the units of production method. The cost of unproved oil and gas properties is excluded from this computation. In the All Other category, for timber properties, depletion, determined on a property by property basis, is charged to operations based on the actual amount of timber cut in relation to the total amount of recoverable timber. For all other property, plant and equipment, depreciation and amortization is computed using the straight-line method in amounts sufficient to recover costs over the estimated service lives of property in service. The following is a summary of depreciable plant by segment:
		As of September 30
		2014				2013
		(Thousands)
	Exploration and Production	$	3,996,834			$	3,437,767
	Pipeline and Storage	1,609,593				1,547,192
	Gathering	239,507				130,082
	Utility	1,833,104				1,778,140
	Energy Marketing	3,366				3,460
	All Other and Corporate	108,986				109,690
		$	7,791,390			$	7,006,331
	Average depreciation, depletion and amortization rates are as follows:
		Year Ended September 30
		2014				2013			2012
	Exploration and Production, per Mcfe(1)	$	1.85			$	2.02		$	2.25
	Pipeline and Storage	2.4		%		2.5		%	2.9		%
	Gathering	3.3		%		3.7		%	3.3		%
	Utility	2.6		%		2.6		%	2.6		%
	Energy Marketing	5.8		%		3.9		%	3.6		%
	All Other and Corporate	0.9		%		1.3		%	1.1		%
	-1	Amounts include depletion of oil and gas producing properties as well as depreciation of fixed assets. As disclosed in Note M — Supplementary Information for Oil and Gas Producing Properties, depletion of oil and gas producing properties amounted to $1.82, $1.98 and $2.19 per Mcfe of production in 2014, 2013 and 2012, respectively.
	Goodwill
	The Company has recognized goodwill of $5.5 million as of September 30, 2014 and 2013 on its Consolidated Balance Sheets related to the Company’s acquisition of Empire in 2003. The Company accounts for goodwill in accordance with the current authoritative guidance, which requires the Company to test goodwill for impairment annually. At September 30, 2014, 2013 and 2012, the fair value of Empire was greater than its book value. As such, the goodwill was not considered impaired at those dates. Going back to the origination of the goodwill in 2003, the Company has never recorded an impairment of its goodwill balance.
	Financial Instruments
	Unrealized gains or losses from the Company’s investments in an equity mutual fund and the stock of an insurance company (securities available for sale) are recorded as a component of accumulated other comprehensive income (loss). Reference is made to Note G — Financial Instruments for further discussion.
	The Company uses a variety of derivative financial instruments to manage a portion of the market risk associated with fluctuations in the price of natural gas and crude oil. These instruments include price swap agreements and futures contracts. The Company accounts for these instruments as either cash flow hedges or fair value hedges. In both cases, the fair value of the instrument is recognized on the Consolidated Balance Sheets as either an asset or a liability labeled Fair Value of Derivative Financial Instruments. Reference is made to Note F — Fair Value Measurements for further discussion concerning the fair value of derivative financial instruments.
	For effective cash flow hedges, the offset to the asset or liability that is recorded is a gain or loss recorded in accumulated other comprehensive income (loss) on the Consolidated Balance Sheets. The gain or loss recorded in accumulated other comprehensive income (loss) remains there until the hedged transaction occurs, at which point the gains or losses are reclassified to operating revenues or purchased gas expense on the Consolidated Statements of Income. Reference is made to Note G - Financial Instruments for further discussion concerning cash flow hedges.
	For fair value hedges, the offset to the asset or liability that is recorded is a gain or loss recorded to operating revenues or purchased gas expense on the Consolidated Statements of Income. However, in the case of fair value hedges, the Company also records an asset or liability on the Consolidated Balance Sheets representing the change in fair value of the asset or firm commitment that is being hedged (see Other Current Assets section in this footnote). The offset to this asset or liability is a gain or loss recorded to operating revenues or purchased gas expense on the Consolidated Statements of Income as well. If the fair value hedge is effective, the gain or loss from the derivative financial instrument is offset by the gain or loss that arises from the change in fair value of the asset or firm commitment that is being hedged. Reference is made to Note G - Financial Instruments for further discussion concerning fair value hedges.
	Accumulated Other Comprehensive Income (Loss)
	The components of Accumulated Other Comprehensive Income (Loss) and changes for the year ended September 30, 2014, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands):
		Gains and Losses on Derivative Financial Instruments				Gains and Losses on Securities Available for Sale			Funded Status of the Pension and Other Post-Retirement Benefit Plans			Total
	Year Ended September 30, 2014
	Balance at October 1, 2013	$	30,722			$	6,337		$	(56,293	)	$	(19,234	)
	Other Comprehensive Gains and Losses Before Reclassifications	4,805				2,465			(5,560		)	1,710
	Amounts Reclassified From Other Comprehensive Loss	8,132				(420		)	5,833			13,545
	Balance at September 30, 2014	$	43,659			$	8,382		$	(56,020	)	$	(3,979	)
	The amounts included in accumulated other comprehensive income (loss) related to the funded status of the Company’s pension and other post-retirement benefit plans consist of prior service costs and accumulated losses. The total amount for prior service credit was $0.2 million and $0.3 million at September 30, 2014 and 2013, respectively. The total amount for accumulated losses was $56.2 million and $56.6 million at September 30, 2014 and 2013, respectively.
Reclassifications Out of Accumulated Other Comprehensive Loss
The details about the reclassification adjustments out of accumulated other comprehensive loss for the year ended September 30, 2014 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands):
Details About Accumulated Other		Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Loss for the				Affected Line Item in the Statement Where Net Income is Presented
Comprehensive Loss Components		Year Ended
		30-Sep-14
Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges:
Commodity Contracts			($14,880	)		Operating Revenues
Commodity Contracts		(2,767		)		Purchased Gas
Gains (Losses) on Securities Available for Sale		662				Other Income
Amortization of Prior Year Funded Status of the Pension and Other Post-Retirement Benefit Plans:
Prior Service Credit		131				-1
Net Actuarial Loss		(9,334		)		-1
		(26,188		)		Total Before Income Tax
		12,643				Income Tax Expense
			($13,545	)		Net of Tax
-1	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note H — Retirement Plan and Other Post-Retirement Benefits for additional details.
Gas Stored Underground — Current
In the Utility segment, gas stored underground — current in the amount of $25.3 million is carried at lower of cost or market, on a LIFO method. Based upon the average price of spot market gas purchased in September 2014, including transportation costs, the current cost of replacing this inventory of gas stored underground — current exceeded the amount stated on a LIFO basis by approximately $33.2 million at September 30, 2014. All other gas stored underground — current, which is in the Energy Marketing segment, is carried at an average cost method, subject to lower of cost or market adjustments.
Unamortized Debt Expense
Costs associated with the issuance of debt by the Company are deferred and amortized over the lives of the related debt.
Costs associated with the reacquisition of debt related to rate-regulated subsidiaries are deferred and amortized over the remaining life of the issue or the life of the replacement debt in order to match regulatory treatment. At September 30, 2014, the remaining weighted average amortization period for such costs was approximately 5 years.
Income Taxes
The Company and its subsidiaries file a consolidated federal income tax return. State tax returns are filed on a combined or separate basis depending on the applicable laws in the jurisdictions where tax returns are filed. Investment tax credit, prior to its repeal in 1986, was deferred and is being amortized over the estimated useful lives of the related property, as required by regulatory authorities having jurisdiction.
The Company reports a liability or a reduction of deferred tax assets for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company recognizes interest relating to uncertain tax positions in Other Interest Expense and penalties in Other Income.
Consolidated Statement of Cash Flows
For purposes of the Consolidated Statement of Cash Flows, the Company considers all highly liquid debt instruments purchased with a maturity of generally three months or less to be cash equivalents.
Hedging Collateral Deposits
This is an account title for cash held in margin accounts funded by the Company to serve as collateral for hedging positions. In accordance with its accounting policy, the Company does not offset hedging collateral deposits paid or received against related derivative financial instrument liability or asset balances.
Other Current Assets
The components of the Company’s Other Current Assets are as follows:
	Year Ended September 30
	2014				2013
	(Thousands)
Prepayments	$	10,079			$	10,605
Prepaid Property and Other Taxes	13,743				13,079
Federal Income Taxes Receivable	8,211				1,122
State Income Taxes Receivable	—				3,275
Fair Values of Firm Commitments	—				1,829
Regulatory Assets	22,719				26,995
	$	54,752			$	56,905
Other Accruals and Current Liabilities
The components of the Company’s Other Accruals and Current Liabilities are as follows:
	Year Ended September 30
	2014				2013
	(Thousands)
Accrued Capital Expenditures	$	80,348			$	41,100
Regulatory Liabilities	18,072				20,013
State Income Taxes Payable	5,798				—
Other	32,454				22,833
	$	136,672			$	83,946
Customer Advances
The Company’s Utility and Energy Marketing segments have balanced billing programs whereby customers pay their estimated annual usage in equal installments over a twelve-month period. Monthly payments under the balanced billing programs are typically higher than current month usage during the summer months. During the winter months, monthly payments under the balanced billing programs are typically lower than current month usage. At September 30, 2014 and 2013, customers in the balanced billing programs had advanced excess funds of $19.0 million and $22.0 million, respectively.
Customer Security Deposits
The Company, in its Utility, Pipeline and Storage, and Energy Marketing segments, often times requires security deposits from marketers, producers, pipeline companies, and commercial and industrial customers before providing services to such customers. At September 30, 2014 and 2013, the Company had received customer security deposits amounting to $15.8 million and $16.2 million, respectively.
Earnings Per Common Share
Basic earnings per common share is computed by dividing income available for common stock by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For purposes of determining earnings per common share, the only potentially dilutive securities the Company has outstanding are stock options, SARs, restricted stock units and performance shares. The diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. Stock options, SARs, restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share. For 2014, 2013 and 2012, 1,007 securities, 181,418 securities and 844,872 securities were excluded as being antidilutive, respectively.
Stock-Based Compensation
The Company has various stock option and stock award plans which provide or provided for the issuance of one or more of the following to key employees: incentive stock options, nonqualified stock options, SARs, restricted stock, restricted stock units, performance units or performance shares. The Company follows authoritative guidance which requires the measurement and recognition of compensation cost at fair value for all share-based payments. Stock options and SARs under all plans have exercise prices equal to the average market price of Company common stock on the date of grant, and generally no stock option or SAR is exercisable less than one year or more than ten years after the date of each grant. The Company has chosen the Black-Scholes-Merton closed form model to calculate the compensation expense associated with stock options and SARs.
Restricted stock is subject to restrictions on vesting and transferability. Restricted stock awards entitle the participants to full dividend and voting rights. The market value of restricted stock on the date of the award is recorded as compensation expense over the vesting period. Certificates for shares of restricted stock awarded under the Company’s stock option and stock award plans are held by the Company during the periods in which the restrictions on vesting are effective. Restrictions on restricted stock awards generally lapse ratably over a period of not more than ten years after the date of each grant. Restricted stock units also are subject to restrictions on vesting and transferability. Restricted stock units, both performance and non-performance based, represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. The performance based and non-performance based restricted stock units do not entitle the participants to dividend and voting rights. The accounting for performance based and non-performance based restricted stock units is the same as the accounting for restricted share awards, except that the fair value at the date of grant of the restricted stock units (represented by the market value of Company common stock on the date of the award) must be reduced by the present value of forgone dividends over the vesting term of the award. The fair value of restricted stock units on the date of award is recorded as compensation expense over the vesting period.
Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied. Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period. For performance shares based on a return on capital goal, the fair value at the date of grant of the performance shares is determined by multiplying the expected number of performance shares to be issued by the market value of Company common stock on the date of grant reduced by the present value of forgone dividends. For performance shares based on a total shareholder return goal, the Company uses the Monte Carlo simulation technique to estimate the fair value price at the date of grant.
Refer to Note E — Capitalization and Short-Term Borrowings under the heading “Stock Option and Stock Award Plans” for additional disclosures related to stock-based compensation awards for all plans.
New Authoritative Accounting and Financial Reporting Guidance
In May 2014, the FASB issued authoritative guidance regarding revenue recognition. The authoritative guidance provides a single, comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. This authoritative guidance will be effective as of the Company's first quarter of fiscal 2018 and early adoption is not permitted. The Company is currently evaluating the impact that adoption of this guidance will have on its consolidated financial statements and disclosures.
In June 2014, the FASB issued authoritative guidance regarding accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the employee has completed the requisite service period. This authoritative guidance requires that such performance targets that affect vesting be treated as performance conditions, meaning that the performance target should not be factored in the calculation of the award at the grant date. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved. This authoritative guidance will be effective as of the Company's first quarter of fiscal 2017, with early adoption permitted. The Company is currently evaluating the impact that adoption of this guidance will have on its consolidated financial statements.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation [Abstract]	'
Asset Retirement Obligations	'
	Asset Retirement Obligations
	The Company accounts for asset retirement obligations in accordance with the authoritative guidance that requires entities to record the fair value of a liability for an asset retirement obligation in the period in which it is incurred. An asset retirement obligation is defined as a legal obligation associated with the retirement of a tangible long-lived asset in which the timing and/or method of settlement may or may not be conditional on a future event that may or may not be within the control of the Company. When the liability is initially recorded, the entity capitalizes the estimated cost of retiring the asset as part of the carrying amount of the related long-lived asset. Over time, the liability is adjusted to its present value each period and the capitalized cost is depreciated over the useful life of the related asset. The Company estimates the fair value of its asset retirement obligations based on the discounting of expected cash flows using various estimates, assumptions and judgments regarding certain factors such as the existence of a legal obligation for an asset retirement obligation; estimated amounts and timing of settlements; the credit-adjusted risk-free rate to be used; and inflation rates. Asset retirement obligations incurred in the current period were Level 3 fair value measurements as the inputs used to measure the fair value are unobservable.
	The Company has recorded an asset retirement obligation representing plugging and abandonment costs associated with the Exploration and Production segment’s crude oil and natural gas wells and has capitalized such costs in property, plant and equipment (i.e. the full cost pool).
	In addition to the asset retirement obligation recorded in the Exploration and Production segment, the Company has recorded future asset retirement obligations associated with the plugging and abandonment of natural gas storage wells in the Pipeline and Storage segment and the removal of asbestos and asbestos-containing material in various facilities in the Utility and Pipeline and Storage segments. The Company has also recorded asset retirement obligations for certain costs connected with the retirement of the distribution mains and services components of the pipeline system in the Utility segment and with the transmission mains and other components in the pipeline system in the Pipeline and Storage segment. These retirement costs within the distribution and transmission systems are primarily for the capping and purging of pipe, which are generally abandoned in place when retired, as well as for the clean-up of PCB contamination associated with the removal of certain pipe.
	A reconciliation of the Company’s asset retirement obligations are shown below:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Balance at Beginning of Year	$	119,511		$	119,246		$	75,731
	Liabilities Incurred and Revisions of Estimates	(2,496		)	(4,796		)	41,653
	Liabilities Settled	(6,955		)	(1,744		)	(2,997		)
	Accretion Expense	7,653			6,805			4,859
	Balance at End of Year	$	117,713		$	119,511		$	119,246

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Sep. 30, 2014
Regulatory Assets and Liabilities, Other Disclosures [Abstract]	'
Regulatory Matters	'
	Regulatory Matters
	Regulatory Assets and Liabilities
	The Company has recorded the following regulatory assets and liabilities:
		At September 30
		2014			2013
		(Thousands)
	Regulatory Assets(1):
	Pension Costs(2) (Note H)	$	164,804		$	187,181
	Post-Retirement Benefit Costs(2) (Note H)	17,128			29,838
	Recoverable Future Taxes (Note D)	163,485			163,355
	Environmental Site Remediation Costs(2) (Note I)	25,645			18,104
	NYPSC Assessment(3)	12,730			13,169
	Asset Retirement Obligations(2) (Note B)	12,006			11,837
	Unamortized Debt Expense (Note A)	2,747			3,276
	Other(4)	14,842			19,434
	Total Regulatory Assets	413,387			446,194
	Less: Amounts Included in Other Current Assets	(22,719		)	(26,995		)
	Total Long-Term Regulatory Assets	$	390,668		$	419,199
		At September 30
		2014			2013
		(Thousands)
	Regulatory Liabilities:
	Cost of Removal Regulatory Liability	$	173,199		$	157,622
	Taxes Refundable to Customers (Note D)	91,736			85,655
	Post-Retirement Benefit Costs (Note H)	53,650			37,923
	Amounts Payable to Customers (See Regulatory Mechanisms in Note A)	33,745			12,828
	Off-System Sales and Capacity Release Credits(5)	12,805			10,228
	Other(6)	32,769			33,411
	Total Regulatory Liabilities	397,904			337,667
	Less: Amounts included in Current and Accrued Liabilities	(51,817		)	(32,841		)
	Total Long-Term Regulatory Liabilities	$	346,087		$	304,826
	-1	The Company recovers the cost of its regulatory assets but generally does not earn a return on them. There are a few exceptions to this rule. For example, the Company does earn a return on Unrecovered Purchased Gas Costs and, in the New York jurisdiction of its Utility segment, earns a return, within certain parameters, on the excess of cumulative funding to the pension plan over the cumulative amount collected in rates.
	-2	Included in Other Regulatory Assets on the Consolidated Balance Sheets.
	-3	Amounts are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be recovered from ratepayers in the next 12 months.
	-4	$9,989 and $13,826 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $4,853 and $5,608 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.
	-5	Amounts are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be passed back to ratepayers in the next 12 months.
	-6	$5,267 and $9,785 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $27,502 and $23,626 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.
	If for any reason the Company ceases to meet the criteria for application of regulatory accounting treatment for all or part of its operations, the regulatory assets and liabilities related to those portions ceasing to meet such criteria would be eliminated from the Consolidated Balance Sheets and included in income of the period in which the discontinuance of regulatory accounting treatment occurs.
	Cost of Removal Regulatory Liability
	In the Company’s Utility and Pipeline and Storage segments, costs of removing assets (i.e. asset retirement costs) are collected from customers through depreciation expense. These amounts are not a legal retirement obligation as discussed in Note B — Asset Retirement Obligations. Rather, they are classified as a regulatory liability in recognition of the fact that the Company has collected dollars from the customer that will be used in the future to fund asset retirement costs.
	NYPSC Assessment
	On April 7, 2009, the Governor of the State of New York signed into law an amendment to the Public Service Law increasing the allowed utility assessment from the then current rate of one-third of one percent to one percent of a utility’s in-state gross operating revenue, together with a temporary surcharge (expiring March 31, 2014) equal, as applied, to an additional one percent of the utility’s in-state gross operating revenue. Pursuant to a New York State budget agreement in 2014, the temporary increase in the assessment will be phased out over a three year period ending July 1, 2017. The NYPSC, in a generic proceeding initiated for the purpose of implementing the amended law, has authorized the recovery, through rates, of the full cost of the increased assessment. The assessment is currently being applied to customer bills in the Utility segment’s New York jurisdiction.
	NYPSC Rate Proceeding
	Following negotiations and other proceedings, on December 6, 2013, Distribution Corporation filed an agreement, also executed by the Department of Public Service and intervenors, extending existing rates through, at a minimum, September 30, 2015. Although customer rates were not changed, the parties agreed that the allowed rate of return on equity would be set, for ratemaking purposes, at 9.1%.  Following conventional practice in New York, the agreement authorizes an “earnings sharing mechanism” (“ESM”).  The ESM distributes earnings above the allowed rate of return as follows: from 9.5% to 10.5%, 50% would be allocated to shareholders, and 50% will be deferred for the benefit of customers; above 10.5%, 20% would be allocated to shareholders and 80% will be deferred for the benefit of customers.  The agreement further authorizes, and rates reflect, an increase in Distribution Corporation’s pipeline replacement spending by $8.2 million per year.  The agreement contains other terms and conditions of service that are customary for settlement agreements recently approved by the NYPSC.  The Consolidated Balance Sheet at September 30, 2013 reflected a $7.5 million refund provision related to the settlement agreement. This amount was passed back to ratepayers during 2014 after the NYPSC approved the settlement agreement without modification in an order issued on May 8, 2014.
	Off-System Sales and Capacity Release Credits
	The Company, in its Utility segment, has entered into off-system sales and capacity release transactions. Most of the margins on such transactions are returned to the customer with only a small percentage being retained by the Company. The amount owed to the customer has been deferred as a regulatory liability.

Income_Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The components of federal and state income taxes included in the Consolidated Statements of Income are as follows:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Current Income Taxes —
	Federal	$	34,579		$	(632	)	$	(8	)
	State	12,620			5,503			6,412
	Deferred Income Taxes —
	Federal	116,143			130,318			111,176
	State	26,272			37,569			32,974
		189,614			172,758			150,554
	Deferred Investment Tax Credit	(434		)	(426		)	(581		)
	Total Income Taxes	$	189,180		$	172,332		$	149,973
	Presented as Follows:
	Other Income	$	(434	)	$	(426	)	$	(581	)
	Income Tax Expense	189,614			172,758			150,554
	Total Income Taxes	$	189,180		$	172,332		$	149,973
	Total income taxes as reported differ from the amounts that were computed by applying the federal income tax rate to income before income taxes. The following is a reconciliation of this difference:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	U.S. Income Before Income Taxes	$	488,593		$	432,333		$	370,050
	Income Tax Expense, Computed at U.S. Federal Statutory Rate of 35%	$	171,008		$	151,317		$	129,518
	Increase (Reduction) in Taxes Resulting from:
	State Income Taxes	25,280			27,997			25,601
	Miscellaneous	(7,108		)	(6,982		)	(5,146		)
	Total Income Taxes	$	189,180		$	172,332		$	149,973
	Significant components of the Company’s deferred tax liabilities and assets were as follows:
		At September 30
		2014			2013
		(Thousands)
	Deferred Tax Liabilities:
	Property, Plant and Equipment	$	1,614,515		$	1,504,187
	Pension and Other Post-Retirement Benefit Costs	113,248			124,021
	Other	87,935			75,419
	Total Deferred Tax Liabilities	1,815,698			1,703,627
	Deferred Tax Assets:
	Pension and Other Post-Retirement Benefit Costs	(124,452		)	(130,256		)
	Tax Loss and Credit Carryforwards	(171,423		)	(215,262		)
	Other	(103,863		)	(90,461		)
	Total Deferred Tax Assets	(399,738		)	(435,979		)
	Total Net Deferred Income Taxes	$	1,415,960		$	1,267,648
	Presented as Follows:
	Deferred Tax Liability/(Asset) — Current	$	(40,323	)	$	(79,359	)
	Deferred Tax Liability — Non-Current	1,456,283			1,347,007
	Total Net Deferred Income Taxes	$	1,415,960		$	1,267,648
	As a result of certain realization requirements of the authoritative guidance on stock-based compensation, the table of deferred tax liabilities and assets shown above does not include certain deferred tax assets that arose directly from excess tax deductions related to stock-based compensation. Tax benefits of $4.6 million and $0.7 million relating to the excess stock-based compensation deductions were recorded in Paid in Capital during the years ended September 30, 2014 and September 30, 2013, respectively. Cumulative tax benefits of $34.2 million remain as of September 30, 2014 and September 30, 2013 and will be recorded in Paid in Capital in future years when such tax benefits are realized.
	Regulatory liabilities representing the reduction of previously recorded deferred income taxes associated with rate-regulated activities that are expected to be refundable to customers amounted to $91.7 million and $85.7 million at September 30, 2014 and 2013, respectively. Also, regulatory assets representing future amounts collectible from customers, corresponding to additional deferred income taxes not previously recorded because of prior ratemaking practices, amounted to $163.5 million and $163.4 million at September 30, 2014 and 2013, respectively. Included in the above are regulatory liabilities and assets relating to the tax accounting method change noted below. The amounts are as follows: regulatory liabilities of $52.6 million as of September 30, 2014 and 2013 and regulatory assets of $85.3 million and $82.5 million as of September 30, 2014 and 2013, respectively.
	The following is a reconciliation of the change in unrecognized tax benefits:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Balance at Beginning of Year	$	2,001		$	11,170		$	7,766
	Additions for Tax Positions Related to Current Year	—			700			1,600
	Additions for Tax Positions of Prior Years	2,447			164			2,751
	Reductions for Tax Positions of Prior Years	(1,301		)	(10,033		)	(947		)
	Balance at End of Year	$	3,147		$	2,001		$	11,170
	As a result of certain examinations in progress (discussed below), the Company anticipates the balance of unrecognized tax benefits could be reduced during the next 12 months. As of September 30, 2014, the entire balance of unrecognized tax benefits would favorably impact the effective tax rate, if recognized.
	The IRS is currently conducting examinations of the Company for fiscal 2014 and fiscal 2013 in accordance with the Compliance Assurance Process (“CAP”). The CAP audit employs a real time review of the Company’s books and tax records by the IRS that is intended to permit issue resolution prior to the filing of the tax return. The federal statute of limitations remains open for fiscal 2009 and later years. During fiscal 2009, consent was received from the IRS National Office approving the Company’s application to change its tax method of accounting for certain capitalized costs relating to its utility property. During the year ended September 30, 2013, local IRS examiners issued no-change reports for fiscal 2009, fiscal 2010 and fiscal 2011. During the year ended September 30, 2014, local IRS examiners issued a no-change report for fiscal 2012. The IRS has reserved the right to re-examine these years, pending the anticipated issuance of IRS guidance addressing the issue for natural gas utilities.
	The Company is also subject to various routine state income tax examinations. The Company’s principal subsidiaries operate mainly in four states which have statutes of limitations that generally expire between three to four years from the date of filing of the income tax return.
	As of September 30, 2014, the Company has a federal net operating loss (NOL) carryover of $367 million, which expires in varying amounts between 2023 and 2033, and minimum tax credit carryforwards of $36 million, that have no expiration date. Approximately $10 million of the NOL carryforward is subject to certain annual limitations, and $87 million is attributable to excess tax deductions related to stock-based compensation as discussed above. In addition, the Company has state NOL carryovers in Pennsylvania, California and New York of $297 million, $183 million and $103 million, respectively, which begin to expire in varying amounts between 2025 and 2033.
	On March 31, 2014, the New York State fiscal year 2014-2015 Executive Budget legislation was signed into law. This legislation included numerous tax provisions, including a reduction of the corporate tax rate from 7.1% to 6.5%, effective for tax years beginning after January 1, 2016. This provision resulted in a tax benefit of approximately $2.8 million, which is reflected in the accompanying financial statements.

Capitalization_And_ShortTerm_B

Capitalization And Short-Term Borrowings	12 Months Ended
	Sep. 30, 2014
Capitalization And Short-Term Borrowings [Abstract]	'
Capitalization And Short-Term Borrowings	'
	Capitalization and Short-Term Borrowings
	Summary of Changes in Common Stock Equity
									Paid In				Earnings				Accumulated
		Common Stock							Capital				Reinvested				Other
													in the				Comprehensive
													Business				Income
		Shares			Amount												(Loss)
		(Thousands, except per share amounts)
	Balance at September 30, 2011	82,813			$	82,813			$	650,749			$	1,206,022			$	(47,699	)
	Net Income Available for Common Stock												220,077
	Dividends Declared on Common Stock ($1.44 Per Share)												(119,815		)
	Other Comprehensive Loss, Net of Tax																(51,321		)
	Share-Based Payment Expense(2)								7,156
	Common Stock Issued Under Stock and Benefit Plans(1)	517			517				11,596
	Balance at September 30, 2012	83,330			83,330				669,501				1,306,284				(99,020		)
	Net Income Available for Common Stock												260,001
	Dividends Declared on Common Stock ($1.48 Per Share)												(123,668		)
	Other Comprehensive Income, Net of Tax																79,786
	Share-Based Payment Expense(2)								11,537
	Common Stock Issued Under Stock and Benefit Plans(1)	332			332				6,646
	Balance at September 30, 2013	83,662			83,662				687,684				1,442,617				(19,234		)
	Net Income Available for Common Stock												299,413
	Dividends Declared on Common Stock ($1.52 Per Share)												(127,669		)
	Other Comprehensive Income, Net of Tax																15,255
	Share-Based Payment Expense(2)								10,654
	Common Stock Issued Under Stock and Benefit Plans(1)	495			495				17,806
	Balance at September 30, 2014	84,157			$	84,157			$	716,144			$	1,614,361		-3	$	(3,979	)
	-1	Paid in Capital includes tax benefits of $4.6 million, $0.7 million and $1.0 million for September 30, 2014, 2013 and 2012, respectively, related to stock-based compensation.
	-2	Paid in Capital includes compensation costs associated with stock option, SARs, performance share and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.
	-3	The availability of consolidated earnings reinvested in the business for dividends payable in cash is limited under terms of the indentures covering long-term debt. At September 30, 2014, $1.5 billion of accumulated earnings was free of such limitations.
	Common Stock
	The Company has various plans which allow shareholders, employees and others to purchase shares of the Company common stock. The National Fuel Gas Company Direct Stock Purchase and Dividend Reinvestment Plan allows shareholders to reinvest cash dividends and make cash investments in the Company’s common stock and provides investors the opportunity to acquire shares of the Company common stock without the payment of any brokerage commissions in connection with such acquisitions. The 401(k) Plans allow employees the opportunity to invest in the Company common stock, in addition to a variety of other investment alternatives. Generally, at the discretion of the Company, shares purchased under these plans are either original issue shares purchased directly from the Company or shares purchased on the open market by an independent agent. During 2014, the Company issued 93,731 original issue shares of common stock for the Direct Stock Purchase and Dividend Reinvestment Plan and 69,729 original issue shares of common stock for the Company's 401(k) plans.
	During 2014, the Company issued 433,602 original issue shares of common stock as a result of stock option and SARs exercises and 12,432 original issue shares of common stock for restricted stock units that vested. Holders of stock options, SARs, restricted share awards or restricted stock units will often tender shares of common stock to the Company for payment of option exercise prices and/or applicable withholding taxes. During 2014, 126,321 shares of common stock were tendered to the Company for such purposes. The Company considers all shares tendered as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law. There were also 3,334 restricted stock award shares forfeited during 2014.
	The Company also has a director stock program under which it issues shares of Company common stock to the non-employee directors of the Company who receive compensation under the Company’s 2009 Non-Employee Director Equity Compensation Plan, as partial consideration for the directors’ services during the fiscal year. Under this program, the Company issued 15,412 original issue shares of common stock during 2014.
	Shareholder Rights Plan
	In 1996, the Company’s Board of Directors adopted a shareholder rights plan (Plan). The Plan has been amended several times since it was adopted and is now embodied in an Amended and Restated Rights Agreement effective December 4, 2008, a copy of which was included as an exhibit to the Form 8-K filed by the Company on December 4, 2008.
	Pursuant to the Plan, the holders of the Company’s common stock have one right (Right) for each of their shares. Each Right is initially evidenced by the Company’s common stock certificates representing the outstanding shares of common stock.
	The Rights have anti-takeover effects because they will cause substantial dilution of the Company’s common stock if a person (an Acquiring Person) attempts to acquire the Company on terms not approved by the Board of Directors.
	The Rights become exercisable upon the occurrence of a Distribution Date as described below, but after a Distribution Date Rights that are owned by an Acquiring Person will be null and void. At any time following a Distribution Date, each holder of a Right may exercise its right to receive, upon payment of an amount calculated under the Rights Agreement, common stock of the Company (or, under certain circumstances, other securities or assets of the Company) having a value equal to two times the amount paid to exercise the Right. However, the Rights are subject to redemption or exchange by the Company prior to their exercise as described below.
	A Distribution Date would occur upon the earlier of (i) ten days after the public announcement that a person or group has acquired, or obtained the right to acquire, beneficial ownership of the Company’s common stock or other voting stock (including Synthetic Long Positions as defined in the Plan) having 10% or more of the total voting power of the Company’s common stock and other voting stock and (ii) ten days after the commencement or announcement by a person or group of an intention to make a tender or exchange offer that would result in that person acquiring, or obtaining the right to acquire, beneficial ownership of the Company’s common stock or other voting stock having 10% or more of the total voting power of the Company’s common stock and other voting stock.
	In certain situations after a person or group has acquired beneficial ownership of 10% or more of the total voting power of the Company’s stock as described above, each holder of a Right will have the right to exercise its Rights to receive, upon exercise of the right, common stock of the acquiring company having a value equal to two times the amount paid to exercise the right. These situations would arise if the Company is acquired in a merger or other business combination or if 50% or more of the Company’s assets or earning power are sold or transferred.
	At any time prior to the end of the business day on the tenth day following the Distribution Date, the Company may redeem the Rights in whole, but not in part, at a price of $0.005 per Right, payable in cash or stock. A decision to redeem the Rights requires the vote of 75% of the Company’s full Board of Directors. Also, at any time following the Distribution Date, 75% of the Company’s full Board of Directors may vote to exchange the Rights, in whole or in part, at an exchange rate of one share of common stock, or other property deemed to have the same value, per Right, subject to certain adjustments.
	Upon exercise of the Rights, the Company may need additional regulatory approvals to satisfy the requirements of the Rights Agreement. The Rights will expire on July 31, 2018, unless earlier than that date, they are exchanged or redeemed or the Plan is amended to extend the expiration date.
	Stock Option and Stock Award Plans
	The Company has various stock option and stock award plans which provide or provided for the issuance of one or more of the following to key employees: incentive stock options, nonqualified stock options, SARs, restricted stock, restricted stock units, performance units or performance shares.
	Stock-based compensation expense for the years ended September 30, 2014, 2013 and 2012 was approximately $10.5 million, $11.5 million, and $7.2 million, respectively. Stock-based compensation expense is included in operation and maintenance expense on the Consolidated Statements of Income. The total income tax benefit related to stock-based compensation expense during the years ended September 30, 2014, 2013 and 2012 was approximately $4.3 million, $4.6 million and $2.9 million, respectively. A portion of stock-based compensation expense is subject to capitalization under IRS uniform capitalization rules. Stock-based compensation of $0.1 million and less than $0.1 million was capitalized under these rules during the years ended September 30, 2014 and 2013, respectively. Nothing was capitalized during the year ended September 30, 2012.
	The Company realized excess tax benefits related to stock-based compensation of $3.1 million, $3.6 million, and $14.2 million for the fiscal years ended September 30, 2014, 2013 and 2012, respectively. The Company recorded tax benefits of $4.6 million, $0.7 million, and $1.0 million in the fiscal years ended September 30, 2014, 2013 and 2012, respectively, due to tax loss carryforwards.
	Stock Options
	Transactions involving option shares for all plans are summarized as follows:
		Number of			Weighted				Weighted		Aggregate
		Shares Subject			Average				Average		Intrinsic
		to Option			Exercise Price				Remaining		Value
									Contractual
									Life (Years)
											(In thousands)
	Outstanding at September 30, 2013	803,500			$	34.71
	Granted in 2014	—			$	—
	Exercised in 2014	(321,500	)		$	31.71
	Forfeited in 2014	—			$	—
	Outstanding at September 30, 2014	482,000			$	36.71			1.8		$	16,039
	Option shares exercisable at September 30, 2014	482,000			$	36.71			1.8		$	16,039
	Option shares available for future grant at September 30, 2014(1)	712,232
	-1	Includes shares available for SARs, restricted stock and performance share grants.
The total intrinsic value of stock options exercised during the years ended September 30, 2014, 2013 and 2012 totaled approximately $13.7 million, $11.6 million, and $13.5 million, respectively. For 2014, 2013 and 2012, the amount of cash received by the Company from the exercise of such stock options was approximately $7.4 million, $2.6 million, and $7.6 million, respectively. The Company last granted stock options in fiscal 2007 and all outstanding stock options have been fully vested since fiscal 2010.
SARs
Transactions involving SARs for all plans are summarized as follows:
	Number of			Weighted				Weighted		Aggregate
	Shares Subject			Average				Average		Intrinsic
	To Option			Exercise Price				Remaining		Value
								Contractual
								Life (Years)
										(In thousands)
Outstanding at September 30, 2013	2,002,704			$	46.73
Granted in 2014	—			$	—
Exercised in 2014	(209,222	)		$	34.9
Forfeited in 2014	—			$	—
Canceled in 2014	—			$	—
Outstanding at September 30, 2014	1,793,482			$	48.11			5.93		$	39,246
SARs exercisable at September 30, 2014	1,434,023			$	46.65			5.45		$	33,466
The Company granted 412,970 and 166,000 SARs during the years ended September 30, 2013 and 2012, respectively. The weighted average grant date fair value of SARs granted in 2013 and 2012 was $10.66 per share and $11.20 per share, respectively. The SARs granted in 2013 may be settled in cash, in shares of common stock of the Company, or in a combination of cash and shares of common stock of the Company, as determined by the Company. The SARs granted in 2012 will be settled in shares of common stock of the Company. The Company’s SARs include both performance based and non-performance based SARs, but the performance conditions associated with the performance based SARs at the time of grant have all been subsequently met. The SARs are considered equity awards under the current authoritative guidance for stock-based compensation. The accounting for SARs is the same as the accounting for stock options. The SARs granted during the year ended September 30, 2013 vest and become exercisable annually in one-third increments. The SARs granted during the year ended September 30, 2012 vest annually in one-third increments and become exercisable on the third anniversary of the date of grant. The weighted average grant date fair value of the SARs granted during the years ended September 30, 2013 and 2012 was estimated on the date of grant using the same accounting treatment that is applied for stock options.
The total intrinsic value of SARs exercised during the years ended September 30, 2014, 2013 and 2012 totaled approximately $8.4 million, $0.8 million, and less than $0.1 million, respectively. For the years ended September 30, 2014, 2013 and 2012, 323,188 SARs, 287,168 SARs and 435,169 SARs, respectively, became fully vested. The total fair value of the SARs that became vested during each of the years ended September 30, 2014, 2013 and 2012 was approximately $3.8 million, $3.6 million and $3.8 million, respectively. As of September 30, 2014, unrecognized compensation expense related to SARs totaled approximately $0.5 million, which will be recognized over a weighted average period of 8 months.
The fair value of SARs at the date of grant was estimated using the Black-Scholes-Merton closed form model. The risk-free interest rate is based on the yield of a Treasury Note with a remaining term commensurate with the expected term of the SARs. The expected life is based on historical experience and the expected volatility is based on historical daily stock price returns. For SARs grants during the years ended September 30, 2013 and 2012, it was assumed that there would be no forfeitures, based on the vesting term and the number of grantees. The following weighted average assumptions were used in estimating the fair value of SARs at the date of grant:
	Year Ended September 30
	2014		2013			2012
Risk-Free Interest Rate	N/A		1.55	%		1.59	%
Expected Life (Years)	N/A		8.25			8.25
Expected Volatility	N/A		25.61	%		24.97	%
Expected Dividend Yield (Quarterly)	N/A		0.69	%		0.64	%
Restricted Share Awards
Transactions involving restricted share awards for all plans are summarized as follows:
	Number of			Weighted Average
	Restricted			Fair Value per
	Share Awards			Award
Outstanding at September 30, 2013	127,453			$	51.69
Granted in 2014	—			$	—
Vested in 2014	(34,601	)		$	58.17
Forfeited in 2014	(3,334	)		$	55.09
Outstanding at September 30, 2014	89,518			$	49.05
The Company did not grant any restricted share awards (non-vested stock as defined by the current accounting literature) during the year ended September 30, 2013. The Company granted 41,525 restricted share awards during the year ended September 30, 2012 with a weighted average grant date fair value of $55.09 per share. As of September 30, 2014, unrecognized compensation expense related to restricted share awards totaled approximately $1.3 million, which will be recognized over a weighted average period of 2.7 years.
Vesting restrictions for the outstanding shares of non-vested restricted stock at September 30, 2014 will lapse as follows: 2015 — 29,518 shares; 2016 — 5,000 shares; 2018 — 35,000 shares; and 2021 — 20,000 shares.
Restricted Stock Units
Transactions involving non-performance based restricted stock units for all plans are summarized as follows:
	Number of			Weighted Average
	Restricted			Fair Value per
	Stock Units			Award
Outstanding at September 30, 2013	143,500			$	51.53
Granted in 2014	82,151			$	65.24
Vested in 2014	(12,432	)		$	60.54
Forfeited in 2014	(8,700	)		$	54.53
Outstanding at September 30, 2014	204,519			$	56.36
The Company also granted 44,200 and 68,450 non-performance based restricted stock units during the years ended September 30, 2013 and 2012, respectively. The weighted average fair value of such non-performance based restricted stock units granted in 2013 and 2012 was $51.11 per share and $47.10 per share, respectively. As of September 30, 2014, unrecognized compensation expense related to non-performance based restricted stock units totaled approximately $5.4 million, which will be recognized over a weighted average period of 1.7 years.
Vesting restrictions for the non-performance based restricted stock units outstanding at September 30, 2014 will lapse as follows: 2015 — 49,340 units; 2016 — 61,534 units; 2017 — 59,893 units; 2018 — 22,967 units; and 2019 - 10,785 units.
Transactions involving performance based restricted stock units for all plans are summarized as follows:
	Number of Performance Based			Weighted Average
	Restricted Stock Units			Fair Value per
				Award
Outstanding at September 30, 2013	255,604			$	49.51
Granted in 2014	—			$	—
Vested in 2014	—			$	—
Forfeited in 2014	(21,728	)		$	48.49
Outstanding at September 30, 2014	233,876			$	49.61
The Company granted 255,604 performance based restricted stock units during the year ended September 30, 2013 with a weighted average grant date fair value of $49.51 per share. The Company did not grant any performance based restricted stock units during the year ended September 30, 2012. The performance based restricted stock units granted during the year ended September 30, 2013 must meet a performance condition over the performance cycle of October 1, 2012 to September 30, 2015. The performance condition over the performance cycle, generally stated, is the Company’s total return on capital as compared to the same metric for companies in the Natural Gas Distribution and Integrated Natural Gas Companies group as calculated and reported in the Monthly Utility Reports of AUS, Inc., a leading industry consultant. The number of performance based restricted stock units that will vest will depend upon the Company’s performance relative to the report group and not upon the absolute level of return achieved by the Company. As of September 30, 2014, unrecognized compensation expense related to performance based restricted stock units totaled approximately $3.1 million, which will be recognized over a weighted average period of 1 year. Vesting restrictions will lapse during fiscal 2016 for the 233,876 performance based restricted stock units outstanding at September 30, 2014.
Performance Shares
Transactions involving performance shares for all plans are summarized as follows:
	Number of			Weighted Average
	Performance			Fair Value per
	Shares			Award
Outstanding at September 30, 2013	—			$	—
Granted in 2014	116,090			$	67.16
Vested in 2014	—			$	—
Forfeited in 2014	(17,624	)		$	67.16
Outstanding at September 30, 2014	98,466			$	67.16
The Company did not grant any performance shares during the years ended September 30, 2013 and 2012. As of September 30, 2014, unrecognized compensation expense related to performance shares totaled approximately $4.6 million, which will be recognized over a weighted average period of 1.5 years. Vesting restrictions will lapse during fiscal 2017 for the 98,466 performance shares outstanding at September 30, 2014.
Half of the performance shares granted during the year ended September 30, 2014 must meet a performance goal related to relative return on capital over the performance cycle of October 1, 2013 to September 30, 2016.  The performance goal over the performance cycle is the Company’s total return on capital relative to the total return on capital of other companies in a group selected by the Compensation Committee (“Report Group”).  Total return on capital for a given company means the average of the Report Group companies’ returns on capital for each twelve month period corresponding to each of the Company’s fiscal years during the performance cycle, based on data reported for the Report Group companies in the Bloomberg database.  The number of these performance shares that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company.  The fair value of these performance shares is calculated by multiplying the expected number of shares that will be issued by the average market price of Company common stock on the date of grant reduced by the present value of forgone dividends over the vesting term of the award.  The fair value is recorded as compensation expense over the vesting term of the award.
The other half of the performance shares granted during the year ended September 30, 2014 must meet a performance goal related to relative total shareholder return over the performance cycle of October 1, 2013 to September 30, 2016.  The performance goal over the performance cycle is the Company’s three-year total shareholder return relative to the three-year total shareholder return of the other companies in the Report Group.  Three-year total shareholder return for a given company will be based on the data reported for that company (with the starting and ending stock prices over the performance cycle calculated as the average closing stock price for the prior calendar month and with dividends reinvested in that company’s securities at each ex-dividend date) in the Bloomberg database.  The number of these total shareholder return performance shares (“TSR performance shares”) that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company.  The fair value price at the date of grant for the TSR performance shares is determined using a Monte Carlo simulation technique, which includes a reduction in value for the present value of forgone dividends over the vesting term of the award.  This price is multiplied by the number of TSR performance shares awarded, the result of which is recorded as compensation expense over the vesting term of the award. In calculating fair value of the award, the risk-free interest rate is based on the yield of a Treasury Note with a term commensurate with the remaining term of the TSR performance shares. The remaining term is based on the remainder of the performance cycle as of the date of grant. The expected volatility is based on historical daily stock price returns. For the TSR performance shares, it was assumed that there would be no forfeitures, based on the vesting term and the number of grantees. The following assumptions were used in estimating the fair value of the TSR performance shares at the date of grant:
	Year Ended September 30
	2014			2013		2012
Risk-Free Interest Rate	0.62	%		N/A		N/A
Remaining Term at Date of Grant (Years)	2.78			N/A		N/A
Expected Volatility	28.3	%		N/A		N/A
Expected Dividend Yield (Quarterly)	N/A			N/A		N/A
Redeemable Preferred Stock
As of September 30, 2014, there were 10,000,000 shares of $1 par value Preferred Stock authorized but unissued.
Long-Term Debt
The outstanding long-term debt is as follows:
	At September 30
	2014				2013
	(Thousands)
Medium-Term Notes(1):
7.4% due March 2023 to June 2025	$	99,000			$	99,000
Notes(1)(3):
3.75% to 8.75% due April 2018 to March 2023	1,550,000				1,550,000
Total Long-Term Debt	1,649,000				1,649,000
Less Current Portion(2)	—				—
	$	1,649,000			$	1,649,000
-1	The Medium-Term Notes and Notes are unsecured.
-2	None of the Company’s long-term debt at September 30, 2014 and 2013 will mature within the following twelve-month period.
-3	The holders of these notes may require the Company to repurchase their notes at a price equal to 101% of the principal amount in the event of both a change in control and a ratings downgrade to a rating below investment grade.
On February 15, 2013, the Company issued $500 million of 3.75% notes due March 1, 2023. After deducting underwriting discounts and commissions, the net proceeds to the Company amounted to $495.4 million. The proceeds of this debt issuance were used to refund the $250.0 million of 5.25% notes that matured in March 2013, as well as for general corporate purposes, including the reduction of short-term debt.
As of September 30, 2014, the aggregate principal amounts of long-term debt maturing during the next five years and thereafter are as follows: zero for 2015 through 2017, $300.0 million in 2018, $250.0 million in 2019 and $1,099.0 million thereafter.
Short-Term Borrowings
The Company historically has obtained short-term funds either through bank loans or the issuance of commercial paper. The Company maintains a $750.0 million syndicated committed credit facility, which commitment extends through January 6, 2017. The Company also has a number of individual uncommitted or discretionary lines of credit with certain financial institutions for general corporate purposes. Borrowings under the uncommitted lines of credit are made at competitive market rates. The uncommitted credit lines are reviewed on an annual basis. The Company anticipates that its uncommitted lines of credit generally will be renewed or substantially replaced by similar lines. The total amount available to be issued under the Company’s commercial paper program is $300.0 million. At September 30, 2014, the commercial paper program was backed by the $750.0 million syndicated committed credit facility.
At September 30, 2014, the Company had outstanding commercial paper of $85.6 million. The Company did not have any outstanding notes payable to banks at September 30, 2014. At September 30, 2014, the weighted average interest rate on the commercial paper was 0.31% . The Company had no outstanding commercial paper and short-term notes payable to banks at September 30, 2013.
Debt Restrictions
Under the committed credit facility, the Company agreed that its debt to capitalization ratio will not exceed .65 at the last day of any fiscal quarter through January 6, 2017. At September 30, 2014, the Company’s debt to capitalization ratio (as calculated under the facility) was .42. The constraints specified in the committed credit facility would have permitted an additional $2.74 billion in short-term and/or long-term debt to be outstanding (further limited by the indenture covenants discussed below) before the Company’s debt to capitalization ratio exceeded .65.
If a downgrade in any of the Company’s credit ratings were to occur, access to the commercial paper markets might not be possible. However, the Company expects that it could borrow under its committed credit facility, uncommitted bank lines of credit or rely upon other liquidity sources, including cash provided by operations.
The Company’s $750.0 million committed credit facility contains a cross-default provision whereby the failure by the Company or its significant subsidiaries to make payments under other borrowing arrangements, or the occurrence of certain events affecting those other borrowing arrangements, could trigger an obligation to repay any amounts outstanding under the committed credit facility. In particular, a repayment obligation could be triggered if (i) the Company or any of its significant subsidiaries fails to make a payment when due of any principal or interest on any other indebtedness aggregating $40.0 million or more, or (ii) an event occurs that causes, or would permit the holders of any other indebtedness aggregating $40.0 million or more to cause, such indebtedness to become due prior to its stated maturity. As of September 30, 2014, the Company had no debt outstanding under the committed credit facility.
Under the Company’s existing indenture covenants, at September 30, 2014, the Company would have been permitted to issue up to a maximum of $1.92 billion in additional long-term unsecured indebtedness at then current market interest rates in addition to being able to issue new indebtedness to replace maturing debt. The Company’s present liquidity position is believed to be adequate to satisfy known demands. However, if the Company were to experience a significant loss in the future (for example, as a result of an impairment of oil and gas properties), it is possible, depending on factors including the magnitude of the loss, that these indenture covenants would restrict the Company’s ability to issue additional long-term unsecured indebtedness for a period of up to nine calendar months, beginning with the fourth calendar month following the loss. This would not at any time preclude the Company from issuing new indebtedness to replace maturing debt.
The Company’s 1974 indenture pursuant to which $99.0 million (or 6.0%) of the Company’s long-term debt (as of September 30, 2014) was issued, contains a cross-default provision whereby the failure by the Company to perform certain obligations under other borrowing arrangements could trigger an obligation to repay the debt outstanding under the indenture. In particular, a repayment obligation could be triggered if the Company fails (i) to pay any scheduled principal or interest on any debt under any other indenture or agreement, or (ii) to perform any other term in any other such indenture or agreement, and the effect of the failure causes, or would permit the holders of the debt to cause, the debt under such indenture or agreement to become due prior to its stated maturity, unless cured or waived.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The FASB authoritative guidance regarding fair value measurements establishes a fair-value hierarchy and prioritizes the inputs used in valuation techniques that measure fair value. Those inputs are prioritized into three levels. Level 1 inputs are unadjusted quoted prices in active markets for assets or liabilities that the Company can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly at the measurement date. Level 3 inputs are unobservable inputs for the asset or liability at the measurement date. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels.
	The following table sets forth, by level within the fair value hierarchy, the Company’s financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of September 30, 2014 and 2013. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The fair value presentation for over the counter swaps has been changed to combine gas and oil swaps at both September 30, 2014 and September 30, 2013. In the September 30, 2013 Form 10-K, gas swaps were reported separately from oil swaps. This change in presentation was made because a significant number of the counterparties enter into both gas and oil swap agreements with the Company.
		At Fair Value as of September 30, 2014
	Recurring Fair Value Measures	Level 1			Level 2			Level 3			Netting			Total(1)
											Adjustments(1)
		(Dollars in thousands)
	Assets:
	Cash Equivalents — Money Market Mutual Funds	$	23,794		$	—		$	—		$	—		$	23,794
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	2,725			—			—			(1,987		)	738
	Over the Counter Swaps — Gas and Oil	—			75,951			1,368			(5,451		)	71,868
	Other Investments:
	Balanced Equity Mutual Fund	35,331			—			—			—			35,331
	Common Stock — Financial Services Industry	6,629			—			—			—			6,629
	Other Common Stock	455			—			—			—			455
	Hedging Collateral Deposits	2,734			—			—			—			2,734
	Total	$	71,668		$	75,951		$	1,368		$	(7,438	)	$	141,549
	Liabilities:
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	$	2,674		$	—		$	—		$	(1,987	)	$	687
	Over the Counter Swaps — Gas and Oil	—			5,523			—			(5,451		)	72
	Total	$	2,674		$	5,523		$	—		$	(7,438	)	$	759
	Total Net Assets/(Liabilities)	$	68,994		$	70,428		$	1,368		$	—		$	140,790
		At Fair Value as of September 30, 2013
	Recurring Fair Value Measures	Level 1			Level 2			Level 3			Netting			Total(1)
											Adjustments(1)
		(Dollars in thousands)
	Assets:
	Cash Equivalents — Money Market Mutual Funds	$	51,332		$	—		$	—		$	—		$	51,332
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	2,552			—			—			(1,641		)	911
	Over the Counter Swaps — Gas and Oil	—			57,070			—			(9,003		)	48,067
	Other Investments:
	Balanced Equity Mutual Fund	31,813			—			—			—			31,813
	Common Stock — Financial Services Industry	6,544			—			—			—			6,544
	Other Common Stock	330			—			—			—			330
	Hedging Collateral Deposits	1,094			—			—			—			1,094
	Total	$	93,665		$	57,070		$	—		$	(10,644	)	$	140,091
	Liabilities:
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	$	1,641		$	—		$	—		$	(1,641	)	$	—
	Over the Counter Swaps — Gas and Oil	—			4,452			5,190			(9,003		)	639
	Total	$	1,641		$	4,452		$	5,190		$	(10,644	)	$	639
	Total Net Assets/(Liabilities)	$	92,024		$	52,618		$	(5,190	)	$	—		$	139,452
	-1	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.
	Derivative Financial Instruments
	At September 30, 2014 and 2013, the derivative financial instruments reported in Level 1 consist of natural gas NYMEX and ICE futures contracts used in the Company’s Energy Marketing segment. Hedging collateral deposits of $2.7 million (at September 30, 2014) and $1.1 million (at September 30, 2013), which are associated with these futures contracts, have been reported in Level 1 as well. The derivative financial instruments reported in Level 2 at September 30, 2014 and 2013 consist of natural gas price swap agreements used in the Company’s Exploration and Production and Energy Marketing segments and the majority of the crude oil price swap agreements used in the Company’s Exploration and Production segment. The fair value of the Level 2 price swap agreements is based on an internal, discounted cash flow model that uses observable inputs (i.e. LIBOR based discount rates and basis differential information, if applicable, at active natural gas and crude oil trading markets). The derivative financial instruments reported in Level 3 consist of a portion of the crude oil price swap agreements used in the Company’s Exploration and Production segment at September 30, 2014 and 2013. The fair value of the Level 3 crude oil price swap agreements is based on an internal, discounted cash flow model that uses both observable (i.e. LIBOR based discount rates) and unobservable inputs (i.e. basis differential information of crude oil trading markets with low trading volume).
	The significant unobservable input used in the fair value measurement of a portion of the Company’s over-the-counter crude oil swaps is the basis differential between Midway Sunset oil and NYMEX contracts. Significant changes in the assumed basis differential could result in a significant change in the value of the derivative financial instruments. At September 30, 2014, it was assumed that Midway Sunset oil was 98.2% of NYMEX. This is based on a historical twelve month average of Midway Sunset oil sales verses NYMEX settlements. During this twelve-month period, the price of Midway Sunset oil ranged from 95.3% to 100.6% of NYMEX. If the price of Midway Sunset oil relative to NYMEX used in the fair value measurement calculation had been 10 percentage points higher, the fair value of the Level 3 crude oil price swap agreements asset would have changed from a net asset of $1.4 million to a net liability of $1.2 million at September 30, 2014. If the price of Midway Sunset oil relative to NYMEX used in the fair value measurement had been 10 percentage points lower, the fair value measurement of the Level 3 crude oil price swap agreements asset would have been approximately $2.6 million higher at September 30, 2014. These calculated amounts are based solely on basis differential changes and do not take into account any other changes to the fair value measurement calculation.
	The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At September 30, 2014, the Company determined that nonperformance risk would have no material impact on its financial position or results of operation. To assess nonperformance risk, the Company considered information such as any applicable collateral posted, master netting arrangements, and applied a market-based method by using the counterparty (for an asset) or the Company’s (for a liability) credit default swaps rates.
	The tables listed below provide reconciliations of the beginning and ending net balances for assets and liabilities measured at fair value and classified as Level 3 for the years ended September 30, 2014 and September 30, 2013, respectively. For the years ended September 30, 2014 and September 30, 2013, no transfers in or out of Level 1 or Level 2 occurred. There were no purchases or sales of derivative financial instruments during the periods presented in the tables below. All settlements of the derivative financial instruments are reflected in the Gains/Losses Realized and Included in Earnings column of the tables below (amounts in parentheses indicate credits in the derivative asset/liability accounts).
	Fair Value Measurements Using Unobservable Inputs (Level 3)
					Total Gains/Losses
		October 1,			(Gains)/Losses			Gains/(Losses)			Transfer			September 30,
		2013			Realized and			Unrealized and			In/(Out) of			2014
					Included in			Included in Other			Level 3
					Earnings			Comprehensive
								Income (Loss)
		(Dollars in thousands)
	Derivative Financial Instruments(2)	$	(5,190	)	$	2,217	-1	$	4,341		$	—		$	1,368
	-1	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2014.
	-2	Derivative Financial Instruments are shown on a net basis.
					Total Gains/Losses
	October 1,			(Gains)/Losses			Gains/(Losses)			Transfer			September 30,
	2012			Realized and			Unrealized and			In/(Out) of			2013
				Included in			Included in Other			Level 3
				Earnings			Comprehensive
							Income (Loss)
	(Dollars in thousands)
Derivative Financial Instruments(2)	$	(19,664	)	$	13,408	-1	$	1,066		$	—		$	(5,190	)
-1	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2013.
-2	Derivative Financial Instruments are shown on a net basis.

Financial_Instruments

Financial Instruments

12 Months Ended

Sep. 30, 2014

Financial Instruments, Owned, at Fair Value [Abstract]

'

Financial Instruments

'

Financial Instruments

Long-Term Debt

The fair market value of the Company’s debt, as presented in the table below, was determined using a discounted cash flow model, which incorporates the Company’s credit ratings and current market conditions in determining the yield, and subsequently, the fair market value of the debt. Based on these criteria, the fair market value of long-term debt, including current portion, was as follows:

At September 30

2014  Carrying

2014 Fair

2013 Carrying

2013 Fair

Amount

Value

Amount

Value

(Thousands)

Long-Term Debt

$

1,649,000

$

1,775,715

$

1,649,000

$

1,767,519

The fair value amounts are not intended to reflect principal amounts that the Company will ultimately be required to pay. Carrying amounts for other financial instruments recorded on the Company’s Consolidated Balance Sheets approximate fair value. The fair value of long-term debt was calculated using observable inputs (U.S. Treasuries/LIBOR for the risk-free component and company specific credit spread information — generally obtained from recent trade activity in the debt). As such, the Company considers the debt to be Level 2.

Temporary cash investments, notes payable to banks and commercial paper are stated at cost. Temporary cash investments are considered Level 1, while notes payable to banks and commercial paper are considered to be Level 2. Given the short-term nature of the notes payable to banks and commercial paper, the Company believes cost is a reasonable approximation of fair value.

Other Investments

Investments in life insurance are stated at their cash surrender values or net present value as discussed below. Investments in an equity mutual fund and the stock of an insurance company (marketable equity securities), as discussed below, are stated at fair value based on quoted market prices.

Other investments include cash surrender values of insurance contracts (net present value in the case of split-dollar collateral assignment arrangements) and marketable equity securities. The values of the insurance contracts amounted to $44.4 million and $57.6 million at September 30, 2014 and 2013, respectively. The fair value of the equity mutual fund was $35.3 million and $31.8 million at September 30, 2014 and 2013, respectively. The gross unrealized gain on this equity mutual fund was $8.4 million at September 30, 2014 and $5.7 million at September 30, 2013. The fair value of the stock of an insurance company was $6.6 million and $6.5 million at September 30, 2014 and 2013, respectively. The gross unrealized gain on this stock was $4.5 million and $4.1 million at September 30, 2014 and 2013, respectively. The insurance contracts and marketable equity securities are primarily informal funding mechanisms for various benefit obligations the Company has to certain employees.

Derivative Financial Instruments

The Company uses derivative financial instruments to manage commodity price risk in the Exploration and Production segment as well as the Energy Marketing segment. The Company enters into futures contracts and over-the-counter swap agreements for natural gas and crude oil to manage the price risk associated with forecasted sales of gas and oil. These instruments are accounted for as cash flow hedges. The Company also enters into futures contracts and swaps, which are accounted for as cash flow hedges, to manage the price risk associated with forecasted gas purchases. The Company enters into futures contracts and swaps to mitigate risk associated with fixed price sales commitments, fixed price purchase commitments, and the decline in value of natural gas held in storage. These instruments are accounted for as fair value hedges. The duration of the Company’s combined cash flow and fair value hedges does not typically exceed 5 years. The Exploration and Production segment holds the majority of the Company’s derivative financial instruments. The derivative financial instruments held by the Energy Marketing segment are not considered to be material to the Company.

The Company has presented its net derivative assets and liabilities as “Fair Value of Derivative Financial Instruments” on its Consolidated Balance Sheets at September 30, 2014 and September 30, 2013. All of the derivative financial instruments reported on those line items relate to commodity contracts.

Cash Flow Hedges

For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current earnings.

As of September 30, 2014, the Company had the following commodity derivative contracts (swaps and futures contracts) outstanding:

Commodity

Units

Natural Gas

212.1

Bcf (short positions)

Natural Gas

3.3

Bcf (long positions)

Crude Oil

3,285,000

Bbls (short positions)

At March 31, 2014, the Company de-designated a portion of its crude oil swaps as cash flow hedges and simultaneously re-designated them as cash flow hedges using a revised effectiveness testing model. Amounts in accumulated other comprehensive loss at March 31, 2014 associated with the de-designated crude oil swaps will be amortized into the income statement as the anticipated hedged production occurs. Since the de-designated crude oil swaps were re-designated as cash flow hedges at March 31, 2014, future gains or losses on such derivatives, to the extent they are effective, will be reported as a component of other comprehensive income (loss) and reclassified into earnings in the period or periods during which the hedged transaction affects earnings. The net mark-to-market impact recorded in earnings related to all of the Company's crude oil swaps, including ineffectiveness and economic hedges, was a loss of $0.1 million and $3.7 million for the years ended September 30, 2014 and September 30, 2013, respectively.

As of September 30, 2014, the Company had $76.1 million ($43.7 million after tax) of net hedging gains included in the accumulated other comprehensive income (loss) balance. It is expected that $41.1 million ($23.6 million after tax) of such unrealized gains will be reclassified into the Consolidated Statement of Income within the next 12 months as the expected sales of the underlying commodities occur. It is expected that $35.0 million ($20.1 million after tax) of unrealized gains will be reclassified into the Consolidated Statement of Income after 12 months as the expected sales of the underlying commodities occur.

Refer to Note A, under Accumulated Other Comprehensive Income (Loss), for the after-tax gain (loss) pertaining to derivative financial instruments.

The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the

Year Ended September 30, 2014 and 2013 (Dollar Amounts in Thousands)

Derivatives in Cash

Amount of

Location of

Amount of

Location of

Derivative Gain or (Loss) Recognized in the Consolidated Statement of Income (Ineffective Portion and Amount Excluded from Effectiveness Testing) for the Year Ended September 30,

Flow Hedging

Derivative Gain or

Derivative Gain or (Loss) Reclassified

Derivative Gain or

Derivative Gain or (Loss) Recognized

Relationships

(Loss) Recognized

from Accumulated

(Loss) Reclassified

in the Consolidated

in Other

Other Comprehensive

from Accumulated

Statement of Income

Comprehensive

Income (Loss) on

Other

(Ineffective Portion

Income (Loss) on

the Consolidated

Comprehensive

and Amount

the Consolidated

Balance Sheet into

Income (Loss) on

Excluded from

Statement of

the Consolidated

the Consolidated

Effectiveness Testing)

Comprehensive

Statement of Income

Balance Sheet into

Income (Loss)

(Effective Portion)

the Consolidated

(Effective Portion)

Statement of Income

for the Year Ended

(Effective Portion)

September 30,

for the Year Ended

September 30,

2014

2013

2014

2013

2014

2013

Commodity Contracts

$

9,763

$

87,813

Operating Revenue

$

(14,880

)

$

36,949

Operating Revenue

$

624

$

(2,045

)

Commodity Contracts

$

(4,429

)

$

3,977

Purchased Gas

$

(2,767

)

$

(920

)

Not Applicable

$

—

$

—

Total

$

5,334

$

91,790

$

(17,647

)

$

36,029

$

624

$

(2,045

)

Fair Value Hedges

The Company utilizes fair value hedges to mitigate risk associated with fixed price sales commitments, fixed price purchase commitments, and the decline in the value of certain natural gas held in storage. With respect to fixed price sales commitments, the Company enters into long positions to mitigate the risk of price increases for natural gas supplies that could occur after the Company enters into fixed price sales agreements with its customers. With respect to fixed price purchase commitments, the Company enters into short positions to mitigate the risk of price decreases that could occur after the Company locks into fixed price purchase deals with its suppliers. With respect to storage hedges, the Company enters into short positions to mitigate the risk of price decreases that could result in a lower of cost or market writedown of the value of natural gas in storage that is recorded in the Company’s financial statements. As of September 30, 2014, the Company’s Energy Marketing segment had fair value hedges covering approximately 16.1 Bcf (15.8 Bcf of fixed price sales commitments, 0.2 Bcf of fixed price purchase commitments and 0.1 Bcf of commitments related to the withdrawal of storage gas). For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting gain or loss on the hedged item attributable to the hedged risk completely offset each other in current earnings, as shown below.

Derivatives in Fair Value Hedging Relationships

Location of Gain or (Loss) on Derivative and Hedged Item Recognized in the Consolidated Statement of Income

Amount of Gain  or

Amount of Gain  or

(Loss) on Derivative

(Loss) on Hedged Item

Recognized in the

Recognized in the

Consolidated

Consolidated

Statement of Income

Statement of Income

for the Year Ended

for the Year Ended

September 30, 2014

September 30, 2014

(In thousands)

Commodity Contracts

Operating Revenues

$

696

$

(696

)

Commodity Contracts

Purchased Gas

(574

)

574

$

122

$

(122

)

Credit Risk

The Company may be exposed to credit risk on any of the derivative financial instruments that are in a gain position. Credit risk relates to the risk of loss that the Company would incur as a result of nonperformance by counterparties pursuant to the terms of their contractual obligations. To mitigate such credit risk, management performs a credit check, and then on a quarterly basis monitors counterparty credit exposure. The majority of the Company’s counterparties are financial institutions and energy traders. The Company has over-the-counter swap positions with sixteen counterparties of which fourteen are in a net gain position. On average, the Company had $5.1 million of credit exposure per counterparty in a gain position at September 30, 2014. The maximum credit exposure per counterparty in a gain position at September 30, 2014 was $18.7 million. As of September 30, 2014, no collateral was received from the counterparties by the Company. The Company’s gain position on such derivative financial instruments had not exceeded the established thresholds at which the counterparties would be required to post collateral, nor had the counterparties’ credit ratings declined to levels at which the counterparties were required to post collateral.

As of September 30, 2014, eleven of the sixteen counterparties to the Company’s outstanding derivative instrument contracts (specifically the over-the-counter swaps) had a common credit-risk related contingency feature. In the event the Company’s credit rating increases or falls below a certain threshold (applicable debt ratings), the available credit extended to the Company would either increase or decrease. A decline in the Company’s credit rating, in and of itself, would not cause the Company to be required to increase the level of its hedging collateral deposits (in the form of cash deposits, letters of credit or treasury debt instruments). If the Company’s outstanding derivative instrument contracts were in a liability position (or if the liability were larger) and/or the Company’s credit rating declined, then additional hedging collateral deposits may be required. At September 30, 2014, the fair market value of the derivative financial instrument assets with a credit-risk related contingency feature was $60.1 million according to the Company’s internal model (discussed in Note F — Fair Value Measurements). At September 30, 2014, the fair market value of the derivative financial instrument liabilities with a credit-risk related contingency feature was $0.1 million according to the Company’s internal model (discussed in Note F — Fair Value Measurements). For its over-the-counter swap agreements, no hedging collateral deposits were required to be posted by the Company at September 30, 2014.

For its exchange traded futures contracts, the Company was required to post $2.7 million in hedging collateral deposits as of September 30, 2014. As these are exchange traded futures contracts, there are no specific credit-risk related contingency features. The Company posts hedging collateral based on open positions and margin requirements it has with its counterparties.

The Company’s requirement to post hedging collateral deposits is based on the fair value determined by the Company’s counterparties, which may differ from the Company’s assessment of fair value. Hedging collateral deposits may also include closed derivative positions in which the broker has not cleared the cash from the account to offset the derivative liability. The Company records liabilities related to closed derivative positions in Other Accruals and Current Liabilities on the Consolidated Balance Sheet. These liabilities are relieved when the broker clears the cash from the hedging collateral deposit account. This is discussed in Note A under Hedging Collateral Deposits.

Retirement_Plan_And_Other_Post

Retirement Plan And Other Post-Retirement Benefits	12 Months Ended
	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Retirement Plan And Other Post-Retirement Benefits	'
	Retirement Plan and Other Post-Retirement Benefits
	The Company has a tax-qualified, noncontributory, defined-benefit retirement plan (Retirement Plan). The Retirement Plan covers certain non-collectively bargained employees hired before July 1, 2003 and certain collectively bargained employees hired before November 1, 2003. Certain non-collectively bargained employees hired after June 30, 2003 and certain collectively bargained employees hired after October 31, 2003 are eligible for a Retirement Savings Account benefit provided under the Company’s defined contribution Tax-Deferred Savings Plans. Costs associated with the Retirement Savings Account were $1.9 million, $1.2 million and $0.9 million for the years ended September 30, 2014, 2013 and 2012, respectively. Costs associated with the Company’s contributions to the Tax-Deferred Savings Plans, exclusive of the costs associated with the Retirement Savings Account, were $5.2 million, $4.4 million, and $4.3 million for the years ended September 30, 2014, 2013 and 2012, respectively.
	The Company provides health care and life insurance benefits (other post-retirement benefits) for a majority of its retired employees. The other post-retirement benefits cover certain non-collectively bargained employees hired before January 1, 2003 and certain collectively bargained employees hired before October 31, 2003.
	The Company’s policy is to fund the Retirement Plan with at least an amount necessary to satisfy the minimum funding requirements of applicable laws and regulations and not more than the maximum amount deductible for federal income tax purposes. The Company has established VEBA trusts for its other post-retirement benefits. Contributions to the VEBA trusts are tax deductible, subject to limitations contained in the Internal Revenue Code and regulations and are made to fund employees’ other post-retirement benefits, as well as benefits as they are paid to current retirees. In addition, the Company has established 401(h) accounts for its other post-retirement benefits. They are separate accounts within the Retirement Plan trust used to pay retiree medical benefits for the associated participants in the Retirement Plan. Although these accounts are in the Retirement Plan trust, for funding status purposes as shown below, the 401(h) accounts are included in Fair Value of Assets under Other Post-Retirement Benefits. Contributions are tax-deductible when made, subject to limitations contained in the Internal Revenue Code and regulations.
	The expected return on Retirement Plan assets, a component of net periodic benefit cost shown in the tables below, is applied to the market-related value of plan assets. The market-related value of plan assets is the market value as of the measurement date adjusted for variances between actual returns and expected returns (from previous years) that have not been reflected in net periodic benefit costs. The expected return on other post-retirement benefit assets (i.e. the VEBA trusts and 401(h) accounts), which is a component of net periodic benefit cost shown in the tables below, is applied to the fair value of assets as of the measurement date.
	Reconciliations of the Benefit Obligations, Plan Assets and Funded Status, as well as the components of Net Periodic Benefit Cost and the Weighted Average Assumptions of the Retirement Plan and other post-retirement benefits are shown in the tables below. The date used to measure the Benefit Obligations, Plan Assets and Funded Status is September 30 for fiscal years 2014, 2013 and 2012.
		Retirement Plan											Other Post-Retirement Benefits
		Year Ended September 30											Year Ended September 30
		2014			2013				2012				2014				2013			2012
		(Thousands)
	Change in Benefit Obligation
	Benefit Obligation at Beginning of Period	$	946,305		$	1,070,744			$	949,777			$	460,634			$	561,263		$	485,452
	Service Cost	11,987			15,846				14,202				2,939				4,705			4,016
	Interest Cost	43,574			36,498				41,526				21,308				19,212			21,315
	Plan Participants’ Contributions	—			—				—				2,265				2,141			1,956
	Retiree Drug Subsidy Receipts	—			—				—				1,419				1,526			1,528
	Actuarial (Gain) Loss	53,887			(121,631		)		120,338				1,087				(104,455		)	71,708
	Benefits Paid	(56,254		)	(55,152		)		(55,099		)		(24,069		)		(23,758		)	(24,712		)
	Benefit Obligation at End of Period	$	999,499		$	946,305			$	1,070,744			$	465,583			$	460,634		$	561,263
	Change in Plan Assets
	Fair Value of Assets at Beginning of Period	$	799,307		$	701,676			$	601,719			$	472,392			$	414,134		$	351,990
	Actual Return on Plan Assets	93,238			98,783				111,034				44,898				61,715			63,552
	Employer Contributions	33,500			54,000				44,022				2,115				18,160			21,348
	Plan Participants’ Contributions	—			—				—				2,265				2,141			1,956
	Benefits Paid	(56,254		)	(55,152		)		(55,099		)		(24,069		)		(23,758		)	(24,712		)
	Fair Value of Assets at End of Period	$	869,791		$	799,307			$	701,676			$	497,601			$	472,392		$	414,134
	Net Amount Recognized at End of Period (Funded Status)	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	32,018			$	11,758		$	(147,129	)
	Amounts Recognized in the Balance Sheets Consist of:
	Non-Current Liabilities	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	(4,494	)		$	(11,016	)	$	(147,129	)
	Non-Current Assets	—			—				—				36,512				22,774			—
	Net Amount Recognized at End of Period	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	32,018			$	11,758		$	(147,129	)
	Accumulated Benefit Obligation	$	940,068		$	886,942			$	986,223			N/A				N/A			N/A
	Weighted Average Assumptions Used to Determine Benefit Obligation at September 30
	Discount Rate	4.25		%	4.75		%		3.5		%		4.25		%		4.75		%	3.5		%
	Rate of Compensation Increase	4.75		%	4.75		%		4.75		%		4.75		%		4.75		%	4.75		%
		Retirement Plan											Other Post-Retirement Benefits
		Year Ended September 30											Year Ended September 30
		2014			2013				2012				2014				2013			2012
		(Thousands)
	Components of Net Periodic Benefit Cost
	Service Cost	$	11,987		$	15,846			$	14,202			$	2,939			$	4,705		$	4,016
	Interest Cost	43,574			36,498				41,526				21,308				19,212			21,315
	Expected Return on Plan Assets	(59,974		)	(57,346		)		(59,701		)		(37,424		)		(32,872		)	(28,971		)
	Amortization of Prior Service Cost (Credit)	210			238				269				(2,138		)		(2,138		)	(2,138		)
	Amortization of Transition Amount	—			—				—				—				8			10
	Recognition of Actuarial Loss(1)	36,007			52,776				39,615				2,645				20,892			24,057
	Net Amortization and Deferral for Regulatory Purposes	8,151			(10,406		)		(6,900		)		23,263				11,844			6,162
	Net Periodic Benefit Cost	$	39,955		$	37,606			$	29,011			$	10,593			$	21,651		$	24,451
	Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost at September 30
	Discount Rate	4.75		%	3.5		%		4.5		%		4.75		%		3.5		%	4.5		%
	Expected Return on Plan Assets	8		%	8		%		8.25		%		8		%		8		%	8.25		%
	Rate of Compensation Increase	4.75		%	4.75		%		4.75		%		4.75		%		4.75		%	4.75		%
	-1	Distribution Corporation’s New York jurisdiction calculates the amortization of the actuarial loss on a vintage year basis over 10 years, as mandated by the NYPSC. All the other subsidiaries of the Company utilize the corridor approach.
	The Net Periodic Benefit Cost in the table above includes the effects of regulation. The Company recovers pension and other post-retirement benefit costs in its Utility and Pipeline and Storage segments in accordance with the applicable regulatory commission authorizations. Certain of those commission authorizations established tracking mechanisms which allow the Company to record the difference between the amount of pension and other post-retirement benefit costs recoverable in rates and the amounts of such costs as determined under the existing authoritative guidance as either a regulatory asset or liability, as appropriate. Any activity under the tracking mechanisms (including the amortization of pension and other post-retirement regulatory assets and liabilities) is reflected in the Net Amortization and Deferral for Regulatory Purposes line item above.
	In addition to the Retirement Plan discussed above, the Company also has Non-Qualified benefit plans that cover a group of management employees designated by the Chief Executive Officer of the Company. These plans provide for defined benefit payments upon retirement of the management employee, or to the spouse upon death of the management employee. The net periodic benefit cost associated with these plans were $7.5 million, $9.6 million and $9.1 million in 2014, 2013 and 2012, respectively. The accumulated benefit obligations for the plans were $65.7 million, $57.2 million and $54.5 million at September 30, 2014, 2013 and 2012, respectively. The projected benefit obligations for the plans were $85.5 million, $77.1 million and $88.5 million at September 30, 2014, 2013 and 2012, respectively. At September 30, 2014, $6.6 million of the projected benefit obligation is recorded in Other Accruals and Current Liabilities and the remaining $78.9 million is recorded in Other Deferred Credits on the Consolidated Balance Sheets. At September 30, 2013 and 2012, the projected benefit obligations are recorded in Other Deferred Credits on the Consolidated Balance Sheets. The weighted average discount rates for these plans were 3.50%, 3.75% and 2.50% as of September 30, 2014, 2013 and 2012, respectively and a weighted average rate of compensation increase of 7.50%, 7.75% and 7.75% as of September 30, 2014, 2013 and 2012, respectively.
	The cumulative amounts recognized in accumulated other comprehensive income (loss), regulatory assets, and regulatory liabilities through fiscal 2014, the changes in such amounts during 2014, as well as the amounts expected to be recognized in net periodic benefit cost in fiscal 2015 are presented in the table below:
		Retirement			Other				Non-Qualified
		Plan			Post-Retirement				Benefit Plans
					Benefits
		(Thousands)
	Amounts Recognized in Accumulated Other Comprehensive Income (Loss), Regulatory Assets and Regulatory Liabilities(1)
	Net Actuarial Loss	$	(226,897	)	$	(32,082	)		$	(23,532	)
	Prior Service (Cost) Credit	(856		)	6,940				—
Net Amount Recognized	$	(227,753	)	$	(25,142	)		$	(23,532	)
Changes to Accumulated Other Comprehensive Income (Loss), Regulatory Assets and Regulatory Liabilities Recognized During Fiscal 2014(1)
Decrease (Increase) in Actuarial Loss, excluding amortization(2)	$	(20,622	)	$	6,387			$	(5,424	)
Change due to Amortization of Actuarial Loss	36,007			2,645				3,008
Prior Service (Cost) Credit	210			(2,138		)		—
Net Change	$	15,595		$	6,894			$	(2,416	)
Amounts Expected to be Recognized in Net Periodic Benefit Cost in the Next Fiscal Year(1)
Net Actuarial Loss	$	(36,129	)	$	(4,148	)		$	(2,925	)
Prior Service (Cost) Credit	(183		)	1,913				—
Net Amount Expected to be Recognized	$	(36,312	)	$	(2,235	)		$	(2,925	)
-1	Amounts presented are shown before recognizing deferred taxes.
-2	Amounts presented include the impact of actuarial gains/losses related to return on assets, as well as the Actuarial (Gain) Loss amounts presented in the Change in Benefit Obligation.
In order to adjust the funded status of its pension (tax-qualified and non-qualified) and other post-retirement benefit plans at September 30, 2014, the Company recorded a $19.2 million decrease to Other Regulatory Assets in the Company’s Utility and Pipeline and Storage segments and a $0.9 million (pre-tax) decrease to Accumulated Other Comprehensive Loss.
The effect of the discount rate change for the Retirement Plan in 2014 was to increase the projected benefit obligation of the Retirement Plan by $53.7 million. In 2014, other actuarial experience increased the projected benefit obligation for the Retirement Plan by $0.2 million. The effect of the discount rate change for the Retirement Plan in 2013 was to decrease the projected benefit obligation of the Retirement Plan by $147.9 million. The effect of the discount rate change for the Retirement Plan in 2012 was to increase the projected benefit obligation of the Retirement Plan by $118.8 million.
The Company made cash contributions totaling $33.5 million to the Retirement Plan during the year ended September 30, 2014. The Company expects that the annual contribution to the Retirement Plan in 2015 will be in the range of $15.0 million to $25.0 million. Changes in the discount rate, other actuarial assumptions, and asset performance could ultimately cause the Company to fund larger amounts to the Retirement Plan in 2015 in order to be in compliance with the Pension Protection Act of 2006 (as impacted by the Moving Ahead for Progress in the 21st Century Act). In July 2012, the Surface Transportation Extension Act, which is also referred to as the Moving Ahead for Progress in the 21st Century Act (the Act), was passed by Congress and signed by the President. The Act included pension funding stabilization provisions. The Highway and Transportation Funding Act of 2014 (HAFTA) was passed by Congress on July 2014 and signed by the President in August 2014. HAFTA extended certain funding stabilization provisions of the Act signed into law in 2012. The Company is continually evaluating its future contributions in light of the provisions of these laws.
The following Retirement Plan benefit payments, which reflect expected future service, are expected to be paid by the Retirement Plan during the next five years and the five years thereafter: $59.4 million in 2015; $60.4 million in 2016; $61.3 million in 2017; $62.2 million in 2018; $62.9 million in 2019; and $326.2 million in the five years thereafter.
The effect of the discount rate change in 2014 was to increase the other post-retirement benefit obligation by $26.4 million. Other actuarial experience decreased the other post-retirement benefit obligation in 2014 by $25.3 million primarily attributable to a revision in assumed per-capita claims cost, premiums and participant contributions based on actual experience.
The effect of the discount rate change in 2013 was to decrease the other post-retirement benefit obligation by $75.9 million. Other actuarial experience decreased the other post-retirement benefit obligation in 2013 by $28.6 million as the increase in obligation attributable to the change in mortality assumption was more than offset by the decrease in obligation attributable to a revision in assumed per-capita claims cost, premiums and participant contributions based on actual experience.
The effect of the discount rate change in 2012 was to increase the other post-retirement benefit obligation by $65.6 million. Other actuarial experience increased the other post-retirement benefit obligation in 2012 by $6.1 million.
The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 provides for a prescription drug benefit under Medicare (Medicare Part D), as well as a federal subsidy to sponsors of retiree health care benefit plans that provide a benefit that is at least actuarially equivalent to Medicare Part D.
The estimated gross other post-retirement benefit payments and gross amount of Medicare Part D prescription drug subsidy receipts are as follows (dollars in thousands):
	Benefit Payments			Subsidy Receipts
2015	$	25,594		$	(1,955	)
2016	$	26,909		$	(2,143	)
2017	$	28,113		$	(2,323	)
2018	$	29,226		$	(2,511	)
2019	$	30,173		$	(2,708	)
2020 through 2024	$	163,470		$	(16,104	)
	2014			2013				2012
Rate of Increase for Pre Age 65 Participants	7.1	%	-1	7.28	%	-1		7.46	%	-1
Rate of Increase for Post Age 65 Participants	6.73	%	-1	6.78	%	-1		6.84	%	-1
Annual Rate of Increase in the Per Capita Cost of Covered Prescription Drug Benefits	7.47	%	-1	7.78	%	-1		8.08	%	-1
Annual Rate of Increase in the Per Capita Medicare Part B Reimbursement	6.73	%	-1	6.78	%	-1		6.84	%	-1
Annual Rate of Increase in the Per Capita Medicare Part D Subsidy	6.79	%	-1	7.03	%	-1		7.13	%	-1
-1	It was assumed that this rate would gradually decline to 4.5% by 2028.
The health care cost trend rate assumptions used to calculate the per capita cost of covered medical care benefits have a significant effect on the amounts reported. If the health care cost trend rates were increased by 1% in each year, the other post-retirement benefit obligation as of October 1, 2014 would increase by $53.0 million. This 1% change would also have increased the aggregate of the service and interest cost components of net periodic post-retirement benefit cost for 2014 by $3.3 million. If the health care cost trend rates were decreased by 1% in each year, the other post-retirement benefit obligation as of October 1, 2014 would decrease by $44.6 million. This 1% change would also have decreased the aggregate of the service and interest cost components of net periodic post-retirement benefit cost for 2014 by $2.8 million.
The Company made cash contributions totaling $2.0 million to its VEBA trusts and 401(h) accounts during the year ended September 30, 2014. In addition, the Company made direct payments of $0.1 million to retirees not covered by the VEBA trusts and 401(h) accounts during the year ended September 30, 2014. The Company expects that the annual contribution to its VEBA trusts and 401(h) accounts in 2015 will be in the range of $2.0 million to $5.0 million.
Investment Valuation
The Retirement Plan assets and other post-retirement benefit assets are valued under the current fair value framework. See Note F — Fair Value Measurements for further discussion regarding the definition and levels of fair value hierarchy established by the authoritative guidance.
The inputs or methodologies used for valuing securities are not necessarily an indication of the risk associated with investing in those securities. Below is a listing of the major categories of plan assets held as of September 30, 2014 and 2013, as well as the associated level within the fair value hierarchy in which the fair value measurements in their entirety fall, based on the lowest level input that is significant to the fair value measurement in its entirety (dollars in thousands):
	Total Fair Value			Level 1				Level 2				Level 3
	Amounts at
	September 30, 2014
Retirement Plan Investments
Domestic Equities(1)	$	268,649		$	171,979			$	96,670			$	—
International Equities(2)	80,957			1,969				78,988				—
Global Equities(3)	104,238			—				104,238				—
Domestic Fixed Income(4)	299,494			63,187				236,307				—
International Fixed Income(5)	1,240			508				732				—
Global Fixed Income(6)	93,704			—				93,704				—
Hedge Fund Investments	45,213			—				—				45,213
Real Estate	3,792			—				—				3,792
Cash and Cash Equivalents	33,544			—				33,544				—
Total Retirement Plan Investments	930,831			237,643				644,183				49,005
401(h) Investments	(54,921		)	(14,105		)		(37,907		)		(2,909		)
Total Retirement Plan Investments (excluding 401(h) Investments)	$	875,910		$	223,538			$	606,276			$	46,096
Miscellaneous Accruals, Interest Receivables, and Non-Interest Cash	(6,119		)
Total Retirement Plan Assets	$	869,791
	Total Fair Value			Level 1				Level 2				Level 3
	Amounts at
	September 30, 2013
Retirement Plan Investments
Domestic Equities(1)	$	402,107		$	271,071			$	131,036			$	—
International Equities(2)	103,028			2,355				100,673				—
Global Equities(3)	25,325			—				25,325				—
Domestic Fixed Income(4)	163,750			71,185				92,565				—
International Fixed Income(5)	2,762			1,318				1,444				—
Global Fixed Income(6)	88,084			—				88,084				—
Hedge Fund Investments	42,027			—				—				42,027
Real Estate	2,723			—				—				2,723
Cash and Cash Equivalents	22,694			—				22,694				—
Total Retirement Plan Investments	852,500			345,929				461,821				44,750
401(h) Investments	(49,453		)	(20,141		)		(26,706		)		(2,606		)
Total Retirement Plan Investments (excluding 401(h) Investments)	$	803,047		$	325,788			$	435,115			$	42,144
Miscellaneous Accruals, Interest Receivables, and Non-Interest Cash	(3,740		)
Total Retirement Plan Assets	$	799,307
-1	Domestic Equities include mostly collective trust funds, common stock, and exchange traded funds.
-2	International Equities include mostly collective trust funds and common stock.
-3	Global Equities are comprised of a collective trust fund.
-4	Domestic Fixed Income securities include mostly collective trust funds, corporate/government bonds and mortgages, and exchange traded funds.
-5	International Fixed Income securities include mostly collective trust funds and exchange traded funds.
-6	Global Fixed Income securities are comprised of a collective trust fund.
	Total Fair Value			Level 1				Level 2				Level 3
	Amounts at
	September 30, 2014
Other Post-Retirement Benefit Assets held in VEBA Trusts
Collective Trust Funds — Domestic Equities	$	148,219		$	—			$	148,219			$	—
Collective Trust Funds — International Equities	54,881			—				54,881				—
Exchange Traded Funds — Fixed Income	236,513			236,513				—				—
Cash Held in Collective Trust Funds	6,412			—				6,412				—
Total VEBA Trust Investments	446,025			236,513				209,512				—
401(h) Investments	54,921			14,105				37,907				2,909
Total Investments (including 401(h) Investments)	$	500,946		$	250,618			$	247,419			$	2,909
Miscellaneous Accruals (Including Current and Deferred Taxes, Claims Incurred But Not Reported, Administrative)	(3,345		)
Total Other Post-Retirement Benefit Assets	$	497,601
	Total Fair Value			Level 1				Level 2				Level 3
	Amounts at
	September 30, 2013
Other Post-Retirement Benefit Assets held in VEBA Trusts
Collective Trust Funds — Domestic Equities	$	205,623		$	—			$	205,623			$	—
Collective Trust Funds — International Equities	87,613			—				87,613				—
Exchange Traded Funds — Fixed Income	122,558			122,558				—				—
Real Estate	55			—				—				55
Cash Held in Collective Trust Funds	11,678			—				11,678				—
Total VEBA Trust Investments	427,527			122,558				304,914				55
401(h) Investments	49,453			20,141				26,706				2,606
Total Investments (including 401(h) Investments)	$	476,980		$	142,699			$	331,620			$	2,661
Miscellaneous Accruals (Including Current and Deferred Taxes, Claims Incurred But Not Reported, Administrative)	(4,588		)
Total Other Post-Retirement Benefit Assets	$	472,392
The fair values disclosed in the above tables may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.
The following tables provide a reconciliation of the beginning and ending balances of the Retirement Plan and other post-retirement benefit assets measured at fair value on a recurring basis where the determination of fair value includes significant unobservable inputs (Level 3). Note: For the years ended September 30, 2014 and September 30, 2013, there were no transfers from Level 1 to Level 2. In addition, as shown in the following tables, there were no transfers in or out of Level 3.
		Retirement Plan Level 3 Assets
		(Thousands)
		Hedge			Real				Excluding				Total
		Funds			Estate				401(h)
									Investments
	Balance at September 30, 2012	$	39,956		$	6,170			$	(2,680	)		$	43,446
	Realized Gains/(Losses)	—			(73		)		4				(69		)
	Unrealized Gains/(Losses)	2,071			515				(156		)		2,430
	Purchases	—			188				(11		)		177
	Sales	—			(4,077		)		237				(3,840		)
	Balance at September 30, 2013	42,027			2,723				(2,606		)		42,144
	Realized Gains/(Losses)	—			62				(4		)		58
	Unrealized Gains/(Losses)	3,186			(10		)		(239		)		2,937
	Purchases	—			1,111				(65		)		1,046
	Sales	—			(94		)		5				(89		)
	Balance at September 30, 2014	$	45,213		$	3,792			$	(2,909	)		$	46,096
	Other Post-Retirement Benefit Level 3 Assets
	(Thousands)
	VEBA			Including				Other
	Trust			401(h)				Post-Retirement
	Investments			Investments				Benefit
	Real							Investments
	Estate
Balance at September 30, 2012	$	1,305		$	2,680			$	3,985
Realized Gains/(Losses)	940			(4		)		936
Unrealized Gains/(Losses)	385			156				541
Purchases	—			11				11
Sales	(2,575		)	(237		)		(2,812		)
Balance at September 30, 2013	55			2,606				2,661
Realized Gains/(Losses)	(40		)	4				(36		)
Unrealized Gains/(Losses)	—			239				239
Purchases	—			65				65
Sales	(15		)	(5		)		(20		)
Balance at September 30, 2014	$	—		$	2,909			$	2,909
The Company’s assumption regarding the expected long-term rate of return on plan assets is 7.5% (Retirement Plan) and 7.0% (other post-retirement benefits), effective for fiscal 2015. The return assumption reflects the anticipated long-term rate of return on the plan’s current and future assets. The Company utilizes projected capital market conditions and the plan’s target asset class and investment manager allocations to set the assumption regarding the expected return on plan assets.
The long-term investment objective of the Retirement Plan trust, the VEBA trusts and the 401(h) accounts is to achieve the target total return in accordance with the Company’s risk tolerance. Assets are diversified utilizing a mix of equities, fixed income and other securities (including real estate). The target allocation for the Retirement Plan is 40-60% equity securities, 35-55% fixed income securities and 5-20% other. The target allocation for the VEBA trusts (including 401(h) accounts) is 40-60% equity securities, 40-60% fixed income securities and 0-15% other. Risk tolerance is established through consideration of plan liabilities, plan funded status and corporate financial condition. The assets of the Retirement Plan trusts, VEBA trusts and the 401(h) accounts have no significant concentrations of risk in any one country (other than the United States), industry or entity.
Investment managers are retained to manage separate pools of assets. Comparative market and peer group performance of individual managers and the total fund are monitored on a regular basis, and reviewed by the Company’s Retirement Committee on at least a quarterly basis.
The discount rate which is used to present value the future benefit payment obligations of the Retirement Plan and the Company’s other post-retirement benefits is 4.25% as of September 30, 2014. The discount rate which is used to present value the future benefit payment obligations of the Non-Qualified benefit plans is 3.50% as of September 30, 2014. The Company utilizes the Mercer Yield Curve Above Mean Model to determine the discount rate. The yield curve is a spot rate yield curve that provides a zero-coupon interest rate for each year into the future. Each year’s anticipated benefit payments are discounted at the associated spot interest rate back to the measurement date. The discount rate is then determined based on the spot interest rate that results in the same present value when applied to the same anticipated benefit payments. In determining the spot rates, the model will exclude coupon interest rates that are in the lower 50th percentile based on the assumption that the Company would not utilize more expensive (i.e. lower yield) instruments to settle its liabilities.

Commitments_And_Contingencies

Commitments And Contingencies	12 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments And Contingencies	'
	Commitments and Contingencies
	Environmental Matters
	The Company is subject to various federal, state and local laws and regulations relating to the protection of the environment. The Company has established procedures for the ongoing evaluation of its operations to identify potential environmental exposures and to comply with regulatory requirements.
	It is the Company’s policy to accrue estimated environmental clean-up costs (investigation and remediation) when such amounts can reasonably be estimated and it is probable that the Company will be required to incur such costs. At September 30, 2014, the Company has estimated its remaining clean-up costs related to former manufactured gas plant sites and third party waste disposal sites will be approximately $14.0 million. The main component of this liability is discussed below under "Former Manufactured Gas Plant Sites." This estimated liability has been recorded in Other Deferred Credits on the Consolidated Balance Sheet at September 30, 2014. The Company expects to recover its environmental clean-up costs through rate recovery over a period of approximately 13 years. Other than as discussed below, the Company is currently not aware of any material exposure to environmental liabilities. However, changes in environmental laws and regulations, new information or other factors could adversely impact the Company.
	(i) Former Manufactured Gas Plant Sites
	The Company has incurred investigation and/or clean-up costs at several former manufactured gas plant sites in New York and Pennsylvania. The Company continues to be responsible for future ongoing monitoring and long-term maintenance at two sites.
	The most significant ongoing clean-up matter currently facing the Company is a former manufactured gas plant site located in New York. In February 2009, the Company received approval from the NYDEC of a Remedial Design Work Plan (RDWP) for this site. In October 2010, the Company submitted a RDWP addendum to conduct additional Preliminary Design Investigation field activities necessary to design a successful remediation. As a result of this work, the Company submitted to the NYDEC a proposal to amend the NYDEC’s Record of Decision remedy for the site. In April 2013, the NYDEC approved the Company’s proposed amendment. Final remedial design work for the site has begun. An estimated minimum liability for remediation of this site of $12.6 million has been recorded.
	Other
	The Company, in its Utility segment, Energy Marketing segment, and Exploration and Production segment, has entered into contractual commitments in the ordinary course of business, including commitments to purchase gas, transportation, and storage service to meet customer gas supply needs. The majority of these contracts expire within the next five years. The future gas purchase, transportation and storage contract commitments during the next five years and thereafter are as follows: $263.8 million in 2015, $66.7 million in 2016, $91.8 million in 2017, $91.8 million in 2018, $82.1 million in 2019 and $845.1 million thereafter. Gas prices within the gas purchase contracts are variable based on NYMEX prices adjusted for basis. In the Utility segment, these costs are subject to state commission review, and are being recovered in customer rates. Management believes that, to the extent any stranded pipeline costs are generated by the unbundling of services in the Utility segment’s service territory, such costs will be recoverable from customers.
	The Company has entered into leases for the use of compressors, drilling rigs, buildings, meters and other items. These leases are accounted for as operating leases. The future lease commitments during the next five years and thereafter are as follows: $16.0 million in 2015, $5.8 million in 2016, $5.7 million in 2017, $5.6 million in 2018, $5.3 million in 2019 and $2.4 million thereafter.
	The Company, in its Pipeline and Storage segment and Gathering segment, has entered into several contractual commitments associated with various pipeline, compressor and gathering system expansion projects. As of September 30, 2014, the future contractual commitments related to the expansion projects are $103.9 million in 2015 and $0.5 million in 2016. There are no contractual commitments extending beyond 2016.
	The Company, in its Exploration and Production segment, has entered into contractual obligations associated with hydraulic fracturing and fuel. The future contractual commitments during the next three years are as follows: $95.3 million in 2015, $24.0 million in 2016 and $0.2 million in 2017. There are no contractual commitments extending beyond 2017.
	The Company, in its Utility segment, has entered into contractual obligations associated with the replacement of its legacy mainframe systems. The future contractual commitments during the next two years are as follows: $21.0 million in 2015 and $5.0 million in 2016. There are no contractual commitments extending beyond 2016.
	The Company is involved in other litigation arising in the normal course of business. In addition to the regulatory matters discussed in Note C — Regulatory Matters, the Company is involved in other regulatory matters arising in the normal course of business. These other litigation and regulatory matters may include, for example, negligence claims and tax, regulatory or other governmental audits, inspections, investigations and other proceedings. These matters may involve state and federal taxes, safety, compliance with regulations, rate base, cost of service and purchased gas cost issues, among other things. While these other matters arising in the normal course of business could have a material effect on earnings and cash flows in the period in which they are resolved, an estimate of the possible loss or range of loss, if any, cannot be made at this time.

Business_Segment_Information

Business Segment Information	12 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Business Segment Information	'
	Business Segment Information
	The Company reports financial results for five segments: Exploration and Production, Pipeline and Storage, Gathering, Utility and Energy Marketing. The division of the Company’s operations into reportable segments is based upon a combination of factors including differences in products and services, regulatory environment and geographic factors.
	The Exploration and Production segment, through Seneca, is engaged in exploration for, and development and purchase of, natural gas and oil reserves in California, the Appalachian region of the United States and Kansas.
	The Pipeline and Storage segment operations are regulated by the FERC for both Supply Corporation and Empire. Supply Corporation transports and stores natural gas for utilities (including Distribution Corporation), natural gas marketers (including NFR), exploration and production companies (including Seneca) and pipeline companies in the northeastern United States markets. Empire transports natural gas to major industrial companies, utilities (including Distribution Corporation) and power producers in New York State.
	The Gathering segment is comprised of Midstream Corporation’s operations. Midstream Corporation builds, owns and operates natural gas processing and pipeline gathering facilities in the Appalachian region and currently provides gathering services to Seneca.
	The Utility segment operations are regulated by the NYPSC and the PaPUC and are carried out by Distribution Corporation. Distribution Corporation sells natural gas to retail customers and provides natural gas transportation services in western New York and northwestern Pennsylvania.
	The Energy Marketing segment is comprised of NFR’s operations. NFR markets natural gas to industrial, wholesale, commercial, public authority and residential customers primarily in western and central New York and northwestern Pennsylvania, offering competitively priced natural gas for its customers.
	The data presented in the tables below reflects financial information for the segments and reconciliations to consolidated amounts. The accounting policies of the segments are the same as those described in Note A — Summary of Significant Accounting Policies. Sales of products or services between segments are billed at regulated rates or at market rates, as applicable. The Company evaluates segment performance based on income before discontinued operations, extraordinary items and cumulative effects of changes in accounting (when applicable). When these items are not applicable, the Company evaluates performance based on net income. Energy Marketing segment revenue from external customers and net income for the year ended September 30, 2014 reflect the impact of $8.5 million and $0.6 million, respectively, of unbilled revenue and related incremental margin (net of tax). In prior periods, Energy Marketing segment revenues and related purchased gas costs were recorded when billed, resulting in a one month lag. The impact of not recording unbilled revenue and related costs was immaterial in all prior periods.
		Year Ended September 30, 2014
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Eliminations
		(Thousands)
	Revenue from External Customers(1)	$	804,096	$	200,664	$	673	$	831,156	$	271,993	$	2,108,582	$	3,532		$	967		$	2,113,081
	Intersegment Revenues	$	—	$	83,744	$	69,937	$	18,462	$	1,159	$	173,302	$	—		$	(173,302	)	$	—
	Interest Income	$	1,909	$	284	$	120	$	3,010	$	173	$	5,496	$	106		$	(1,432	)	$	4,170
	Interest Expense	$	42,232	$	26,428	$	1,726	$	27,693	$	31	$	98,110	$	6		$	(3,839	)	$	94,277
	Depreciation, Depletion and Amortization	$	296,210	$	36,642	$	6,116	$	43,594	$	197	$	382,759	$	344		$	678		$	383,781
	Income Tax Expense (Benefit)	$	81,370	$	47,100	$	23,636	$	33,918	$	3,761	$	189,785	$	822		$	(993	)	$	189,614
	Segment Profit: Net Income (Loss)	$	121,569	$	77,559	$	32,709	$	64,059	$	6,631	$	302,527	$	1,160		$	(4,274	)	$	299,413
	Expenditures for Additions to Long-Lived Assets	$	602,705	$	139,821	$	137,799	$	88,810	$	264	$	969,399	$	274		$	234		$	969,907
		At September 30, 2014
		(Thousands)
	Segment Assets	$	3,100,514	$	1,367,181	$	326,662	$	1,862,850	$	76,238	$	6,733,445	$	86,460		$	(80,308	)	$	6,739,597
		Year Ended September 30, 2013
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Elimination
		(Thousands)
	Revenue from External Customers(1)	$	702,937	$	178,184	$	1,324	$	730,319	$	211,990	$	1,824,754	$	3,910		$	887		$	1,829,551
	Intersegment Revenues	$	—	$	89,424	$	33,457	$	16,020	$	1,384	$	140,285	$	—		$	(140,285	)	$	—
	Interest Income	$	1,501	$	193	$	55	$	3,417	$	169	$	5,335	$	115		$	(1,115	)	$	4,335
	Interest Expense	$	39,745	$	26,248	$	2,283	$	29,076	$	36	$	97,388	$	2		$	(3,279	)	$	94,111
	Depreciation, Depletion and Amortization	$	243,431	$	35,156	$	3,945	$	42,729	$	123	$	325,384	$	577		$	799		$	326,760
	Income Tax Expense (Benefit)	$	95,317	$	38,626	$	10,287	$	31,065	$	2,450	$	177,745	$	529		$	(5,516	)	$	172,758
	Segment Profit: Net Income (Loss)	$	115,391	$	63,245	$	13,321	$	65,686	$	4,589	$	262,232	$	894		$	(3,125	)	$	260,001
	Expenditures for Additions to Long-Lived Assets	$	533,129	$	56,144	$	54,792	$	71,970	$	595	$	716,630	$	307		$	160		$	717,097
		At September 30, 2013
		(Thousands)
	Segment Assets	$	2,746,233	$	1,246,027	$	203,323	$	1,870,587	$	67,267	$	6,133,437	$	95,793		$	(10,883	)	$	6,218,347
		Year Ended September 30, 2012
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Eliminations
		(Thousands)
	Revenue from External Customers(1)	$	558,180	$	172,312	$	704	$	704,518	$	186,579	$	1,622,293	$	3,603		$	957		$	1,626,853
	Intersegment Revenues	$	—	$	86,963	$	16,771	$	14,604	$	1,425	$	119,763	$	—		$	(119,763	)	$	—
	Interest Income	$	1,493	$	199	$	1	$	2,765	$	188	$	4,646	$	174		$	(1,131	)	$	3,689
	Interest Expense	$	29,243	$	25,603	$	1,444	$	33,181	$	41	$	89,512	$	294		$	(3,566	)	$	86,240
	Depreciation, Depletion and Amortization	$	187,624	$	38,182	$	1,691	$	42,757	$	90	$	270,344	$	400		$	786		$	271,530
	Income Tax Expense (Benefit)	$	79,050	$	37,655	$	4,825	$	29,110	$	1,933	$	152,573	$	(490	)	$	(1,529	)	$	150,554
	Segment Profit: Net Income (Loss)	$	96,498	$	60,527	$	6,855	$	58,590	$	4,169	$	226,639	$	13		$	(6,575	)	$	220,077
	Expenditures for Additions to Long-Lived Assets	$	693,810	$	144,167	$	80,012	$	58,284	$	770	$	977,043	$	5		$	346		$	977,394
		At September 30, 2012
		(Thousands)
	Segment Assets	$	2,367,485	$	1,243,862	$	116,756	$	2,070,413	$	61,968	$	5,860,484	$	93,178		$	(18,520	)	$	5,935,142
	-1	All Revenue from External Customers originated in the United States.
	Geographic Information	At September 30
		2014		2013		2012
		(Thousands)
Long-Lived Assets:
United States	$	6,362,265	$	5,769,670	$	5,579,566

Quarterly_Financial_Data

Quarterly Financial Data	12 Months Ended
	Sep. 30, 2014
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Financial Data	'
	Quarterly Financial Data (unaudited)
	In the opinion of management, the following quarterly information includes all adjustments necessary for a fair statement of the results of operations for such periods. Per common share amounts are calculated using the weighted average number of shares outstanding during each quarter. The total of all quarters may differ from the per common share amounts shown on the Consolidated Statements of Income. Those per common share amounts are based on the weighted average number of shares outstanding for the entire fiscal year. Because of the seasonal nature of the Company’s heating business, there are substantial variations in operations reported on a quarterly basis.
		Quarter Ended	Operating		Operating		Net  Income			Earnings per
			Revenues		Income		Available for			Common Share
							Common Stock			Basic		Diluted
			(Thousands, except per common share amounts)
		2014
		9/30/14	$	366,623	$	102,004	$	57,431		$	0.68	$	0.68
		6/30/14	$	440,144	$	127,013	$	64,520		$	0.77	$	0.76
		3/31/14	$	756,242	$	180,075	$	95,210	-1	$	1.14	$	1.12
		12/31/13	$	550,072	$	160,581	$	82,252		$	0.98	$	0.97
		2013
		9/30/13	$	338,863	$	96,636	$	47,842	-2	$	0.57	$	0.57
		6/30/13	$	440,008	$	127,004	$	58,495		$	0.7	$	0.69
		3/31/13	$	597,826	$	162,991	$	85,720		$	1.03	$	1.02
		12/31/12	$	452,854	$	131,207	$	67,944		$	0.81	$	0.81
	-1	Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.
	-2	Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

Market_For_Common_Stock_And_Re

Market For Common Stock And Related Shareholder Matters	12 Months Ended
	Sep. 30, 2014
Market For Common Stock And Related Shareholder Matters [Abstract]	'
Market For Common Stock And Related Shareholder Matters (unaudited)	'
	Market for Common Stock and Related Shareholder Matters (unaudited)
	At September 30, 2014, there were 12,654 registered shareholders of Company common stock. The common stock is listed and traded on the New York Stock Exchange. Information related to restrictions on the payment of dividends can be found in Note E — Capitalization and Short-Term Borrowings. The quarterly price ranges (based on intra-day prices) and quarterly dividends declared for the fiscal years ended September 30, 2014 and 2013, are shown below:
		Price Range				Dividends
	Quarter Ended	High		Low		Declared
	2014
	9/30/14	$	78.79	$	65.29	$	0.385
	6/30/14	$	78.46	$	68.5	$	0.385
	3/31/14	$	77.05	$	68.12	$	0.375
	12/31/13	$	72.53	$	65.23	$	0.375
	2013
	9/30/13	$	69.27	$	57.52	$	0.375
	6/30/13	$	64.58	$	56.8	$	0.375
	3/31/13	$	61.44	$	48.51	$	0.365
	12/31/12	$	55.66	$	49	$	0.365

Supplementary_Information_For_

Supplementary Information For Oil And Gas Producing Activities	12 Months Ended
	Sep. 30, 2014
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'
Supplementary Information for Oil and Gas Producing Activities (unaudited, except for Capitalized Costs Relating to Oil and Gas Producing Activities)	'
	Supplementary Information for Oil and Gas Producing Activities (unaudited, except for Capitalized Costs Relating to Oil and Gas Producing Activities)
	The Company follows authoritative guidance related to oil and gas exploration and production activities that aligns the reserve estimation and disclosure requirements with the requirements of the SEC Modernization of Oil and Gas Reporting rule, which the Company also follows. The SEC rules require companies to value their year-end reserves using an unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve month period prior to the end of the reporting period.
	The following supplementary information is presented in accordance with the authoritative guidance regarding disclosures about oil and gas producing activities and related SEC accounting rules. All monetary amounts are expressed in U.S. dollars.
	Capitalized Costs Relating to Oil and Gas Producing Activities
		At September 30
		2014				2013
		(Thousands)
	Proved Properties(1)	$	3,941,143			$	3,393,612
	Unproved Properties	141,719				106,085
		4,082,862				3,499,697
	Less — Accumulated Depreciation, Depletion and Amortization	1,211,610				919,989
		$	2,871,252			$	2,579,708
	-1	Includes asset retirement costs of $75.7 million and $80.6 million at September 30, 2014 and 2013, respectively.
	Costs related to unproved properties are excluded from amortization until proved reserves are found or it is determined that the unproved properties are impaired. All costs related to unproved properties are reviewed quarterly to determine if impairment has occurred. The amount of any impairment is transferred to the pool of capitalized costs being amortized. Although the timing of the ultimate evaluation or disposition of the unproved properties cannot be determined, the Company expects the majority of its acquisition costs associated with unproved properties to be transferred into the amortization base by 2020. It expects the majority of its development and exploration costs associated with unproved properties to be transferred into the amortization base by 2015. Following is a summary of costs excluded from amortization at September 30, 2014:
		Total				Year Costs Incurred
		as of
		September 30,
		2014				2014				2013			2012		Prior
		(Thousands)
	Acquisition Costs	$	61,712			$	7,057			$	905		$	5,585	$	48,165
	Development Costs	42,362				39,339				677			1,405		941
	Exploration Costs	36,882				36,882				—			—		—
	Capitalized Interest	763				763				—			—		—
		$	141,719			$	84,041			$	1,582		$	6,990	$	49,106
	Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities
		Year Ended September 30
		2014				2013				2012
		(Thousands)
	United States
	Property Acquisition Costs:
	Proved	$	18,213			$	7,575			$	13,095
	Unproved	7,884				9,274				13,867
	Exploration Costs(1)	71,850				49,483				84,624
	Development Costs(2)	490,164				460,554				576,397
	Asset Retirement Costs	(4,946		)		37,546				10,344
		$	583,165			$	564,432			$	698,327
	-1	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.4 million and $1.0 million, respectively.
	-2	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.7 million and $2.0 million, respectively.
	For the years ended September 30, 2014, 2013 and 2012, the Company spent $179.9 million, $148.5 million and $216.6 million, respectively, developing proved undeveloped reserves.
	Results of Operations for Producing Activities
		Year Ended September 30
		2014				2013				2012
		(Thousands, except per Mcfe amounts)
	United States
	Operating Revenues:
	Natural Gas (includes revenues from sales to affiliates of $1 for all years presented and transfers to operations of $2,145, $612 and $0, respectively)	$	515,080			$	371,311			$	181,544
	Oil, Condensate and Other Liquids	298,179				291,762				307,018
	Total Operating Revenues(1)	813,259				663,073				488,562
	Production/Lifting Costs	165,534				119,243				83,361
	Franchise/Ad Valorem Taxes	20,765				17,200				23,620
	Accretion Expense	6,192				3,929				3,084
	Depreciation, Depletion and Amortization ($1.82, $1.98 and $2.19 per Mcfe of production)	291,651				238,467				182,759
	Income Tax Expense	140,484				120,431				81,904
	Results of Operations for Producing Activities (excluding corporate overheads and interest charges)	$	188,633			$	163,803			$	113,834
	-1	Exclusive of hedging gains and losses. See further discussion in Note G — Financial Instruments.
	Reserve Quantity Information
	The Company’s proved oil and gas reserve estimates are prepared by the Company’s reservoir engineers who meet the qualifications of Reserve Estimator per the “Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserve Information” promulgated by the Society of Petroleum Engineers as of February 19, 2007. The Company maintains comprehensive internal reserve guidelines and a continuing education program designed to keep its staff up to date with current SEC regulations and guidance.
	The Company’s Vice President of Reservoir Engineering is the primary technical person responsible for overseeing the Company’s reserve estimation process and engaging and overseeing the third party reserve audit. His qualifications include a Bachelor of Science Degree in Petroleum Engineering and over 25 years of Petroleum Engineering experience with both major and independent oil and gas companies. He has maintained oversight of the Company’s reserve estimation process for the past eleven years. He is a member of the Society of Petroleum Engineers and a Registered Professional Engineer in the State of Texas.
	The Company maintains a system of internal controls over the reserve estimation process. Management reviews the price, heat content, lease operating cost and future investment assumptions used in the economic model that determines the reserves. The Vice President of Reservoir Engineering reviews and approves all new reserve assignments and significant reserve revisions. Access to the reserve database is restricted. Significant changes to the reserve report are reviewed by senior management on a quarterly basis. Periodically, the Company’s internal audit department assesses the design of these controls and performs testing to determine the effectiveness of such controls.
	All of the Company’s reserve estimates are audited annually by Netherland, Sewell and Associates, Inc. (NSAI). Since 1961, NSAI has evaluated gas and oil properties and independently certified petroleum reserve quantities in the United States and internationally under the Texas Board of Professional Engineers Registration No. F-002699. The primary technical persons (employed by NSAI) that are responsible for leading the audit include a professional engineer registered with the State of Texas (consulting at NSAI since 2004 and with over 5 years of prior industry experience in petroleum engineering) and a professional geoscientist registered in the State of Texas (consulting at NSAI since 2008 with over 11 years of prior industry experience in petroleum geosciences). NSAI was satisfied with the methods and procedures used by the Company to prepare its reserve estimates at September 30, 2014 and did not identify any problems which would cause it to take exception to those estimates.
	The reliable technologies that were utilized in estimating the reserves include wire line open-hole log data, performance data, log cross sections, core data, 2D and 3D seismic data and statistical analysis. The statistical method utilized production performance from both the Company’s and competitors’ wells. Geophysical data includes data from the Company’s wells, published documents, state data-sites and 2D and 3D seismic data. This data was used to confirm continuity of the formation.
		Gas MMcf
		U. S.
	Appalachian			West			Total
	Region			Coast			Company
				Region
Proved Developed and Undeveloped Reserves:
September 30, 2011	606,606			68,316			674,922
Extensions and Discoveries	435,460		-1	638			436,098
Revisions of Previous Estimates	(53,992	)		(2,463	)		(56,455	)
Production	(62,663	)	-2	(3,468	)		(66,131	)
September 30, 2012	925,411			63,023			988,434
Extensions and Discoveries	360,922		-1	702			361,624
Revisions of Previous Estimates	53,038			112			53,150
Production	(100,633	)	-2	(3,060	)		(103,693	)
September 30, 2013	1,238,738			60,777			1,299,515
Extensions and Discoveries	446,821		-1	—			446,821
Revisions of Previous Estimates	43,690			1,358			45,048
Production	(139,097	)	-2	(3,210	)		(142,307	)
Purchases of Minerals in Place	33,986			—			33,986
Sale of Minerals in Place	(76	)		(103	)		(179	)
September 30, 2014	1,624,062			58,822			1,682,884
Proved Developed Reserves:
September 30, 2011	350,458			63,965			414,423
September 30, 2012	544,560			59,923			604,483
September 30, 2013	807,055			59,862			866,917
September 30, 2014	1,119,901			57,907			1,177,808
Proved Undeveloped Reserves:
September 30, 2011	256,148			4,351			260,499
September 30, 2012	380,851			3,100			383,951
September 30, 2013	431,683			915			432,598
September 30, 2014	504,161			915			505,076
-1	Extensions and discoveries include 435 Bcf (during 2012), 355 Bcf (during 2013) and 442 Bcf (during 2014), of Marcellus Shale gas in the Appalachian Region.
-2	Production includes 55,812 MMcf (during 2012), 93,999 MMcf (during 2013) and 131,590 MMcf (during 2014), from Marcellus Shale fields (which exceed 15% of total reserves).
	Oil Mbbl
	U. S.
	Appalachian			West			Total
	Region			Coast			Company
				Region
Proved Developed and Undeveloped Reserves:
September 30, 2011	279			43,066			43,345
Extensions and Discoveries	28			1,229			1,257
Revisions of Previous Estimates	35			1,095			1,130
Production	(36	)		(2,834	)		(2,870	)
September 30, 2012	306			42,556			42,862
Extensions and Discoveries	—			2,443			2,443
Revisions of Previous Estimates	5			(881	)		(876	)
Production	(28	)		(2,803	)		(2,831	)
September 30, 2013	283			41,315			41,598
Extensions and Discoveries	18			1,521			1,539
Revisions of Previous Estimates	(17	)		(1,677	)		(1,694	)
Production	(31	)		(3,005	)		(3,036	)
Purchases of Minerals in Place	—			83			83
Sales of Minerals in Place	—			(13	)		(13	)
September 30, 2014	253			38,224			38,477
Proved Developed Reserves:
September 30, 2011	274			37,306			37,580
September 30, 2012	306			38,138			38,444
September 30, 2013	283			38,082			38,365
September 30, 2014	253			37,002			37,255
Proved Undeveloped Reserves:
September 30, 2011	5			5,760			5,765
September 30, 2012	—			4,418			4,418
September 30, 2013	—			3,233			3,233
September 30, 2014	—			1,222			1,222
The Company’s proved undeveloped (PUD) reserves increased from 452 Bcfe at September 30, 2013 to 512 Bcfe at September 30, 2014. PUD reserves in the Marcellus Shale increased from 432 Bcf at September 30, 2013 to 504 Bcf at September 30, 2014. The Company’s total PUD reserves were 27% of total proved reserves at September 30, 2014, down from 29% of total proved reserves at September 30, 2013.
The Company’s PUD reserves increased from 410 Bcfe at September 30, 2012 to 452 Bcfe at September 30, 2013. PUD reserves in the Marcellus Shale increased from 381 Bcf at September 30, 2012 to 432 Bcf at September 30, 2013. The Company’s total PUD reserves were 29% of total proved reserves at September 30, 2013, down from 33% of total proved reserves at September 30, 2012.
The increase in PUD reserves in 2014 of 60 Bcfe is a result of 290 Bcfe in new PUD reserve additions (288 Bcfe from the Marcellus Shale), 20 Bcfe in PUD reserves acquired, 12 Bcfe in upward revisions to remaining PUD reserves, offset by 229 Bcfe in PUD conversions to developed reserves and 33 Bcfe in PUD reserves removed. The PUD reserves removed were primarily in the Marcellus Shale (24 Bcfe) in Seneca’s non-operated joint venture in Clearfield County where the operator had previously drilled and cased the horizontal wells to total depth and does not appear now to have firm plans for their completion. An additional 9 Bcfe (1,501 Mbbl) of PUD reserves were removed at the Midway Sunset field in the Tulare reservoir as the Company has no near term plans to develop these reserves as it is employing capital elsewhere.
The increase in PUD reserves in 2013 of 42 Bcfe is a result of 221 Bcfe in new PUD reserve additions (219 Bcfe from the Marcellus Shale), offset by 160 Bcfe in PUD conversions to developed reserves and 19 Bcfe in downward PUD revisions. The downward revisions were primarily due to reductions to planned lateral lengths for several horizontal wells in the Marcellus Shale.
The Company invested $180 million during the year ended September 30, 2014 to convert 229 Bcfe (248 Bcfe including revisions) of PUD reserves to developed reserves. This represents 51% of the PUD reserves booked at September 30, 2013. The Company invested $149 million during the year ended September 30, 2013 to convert 160 Bcfe (171 Bcfe including revisions) of September 30, 2012 PUD reserves to proved developed reserves. This represented 39% of the PUD reserves booked at September 30, 2012. In 2015, the Company estimates that it will invest approximately $239 million to develop its PUD reserves. The Company is committed to developing its PUD reserves within five years as required by the SEC’s final rule on Modernization of Oil and Gas Reporting. Since that rule, and over the last five years, the Company developed 19% of its beginning year PUD reserves in fiscal 2010, 47% of its beginning year PUD reserves in fiscal 2011, 33% of its beginning year PUD reserves in fiscal 2012, 39% of its beginning year PUD reserves in fiscal 2013 and 51% of its beginning year PUD reserves in fiscal 2014.
At September 30, 2014, the Company does not have a material concentration of proved undeveloped reserves that have been on the books for more than five years at the corporate level, country level or field level. All of the Company’s proved reserves are in the United States.
Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves
The Company cautions that the following presentation of the standardized measure of discounted future net cash flows is intended to be neither a measure of the fair market value of the Company’s oil and gas properties, nor an estimate of the present value of actual future cash flows to be obtained as a result of their development and production. It is based upon subjective estimates of proved reserves only and attributes no value to categories of reserves other than proved reserves, such as probable or possible reserves, or to unproved acreage. Furthermore, in accordance with the SEC’s final rule on Modernization of Oil and Gas Reporting, it is based on the unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve-month period prior to the end of the reporting period and costs adjusted only for existing contractual changes. It assumes an arbitrary discount rate of 10%. Thus, it gives no effect to future price and cost changes certain to occur under widely fluctuating political and economic conditions.
The standardized measure is intended instead to provide a means for comparing the value of the Company’s proved reserves at a given time with those of other oil- and gas-producing companies than is provided by a simple comparison of raw proved reserve quantities.
	Year Ended September 30
	2014				2013				2012
	(Thousands)
United States
Future Cash Inflows	$	10,001,545			$	8,943,942			$	7,373,129
Less:
Future Production Costs	2,795,657				2,334,393				1,919,530
Future Development Costs	790,033				749,876				619,573
Future Income Tax Expense at Applicable Statutory Rate	2,434,370				2,113,101				1,812,055
Future Net Cash Flows	3,981,485				3,746,572				3,021,971
Less:
10% Annual Discount for Estimated Timing of Cash Flows	1,914,607				1,780,206				1,552,180
Standardized Measure of Discounted Future Net Cash Flows	$	2,066,878			$	1,966,366			$	1,469,791
The principal sources of change in the standardized measure of discounted future net cash flows were as follows:
	Year Ended September 30
	2014				2013				2012
	(Thousands)
United States
Standardized Measure of Discounted Future
Net Cash Flows at Beginning of Year	$	1,966,366			$	1,469,791			$	1,524,157
Sales, Net of Production Costs	(626,960		)		(526,630		)		(381,581		)
Net Changes in Prices, Net of Production Costs	(38,723		)		339,655				(385,019		)
Extensions and Discoveries	381,008				390,255				224,474
Changes in Estimated Future Development Costs	68,731				6,117				29,627
Purchases of Minerals in Place	34,705				—				—
Sales of Minerals in Place	(691		)		—				—
Previously Estimated Development Costs Incurred	179,502				148,535				252,967
Net Change in Income Taxes at Applicable Statutory Rate	(231,807		)		(130,574		)		(19,280		)
Revisions of Previous Quantity Estimates	55,184				34,864				103,472
Accretion of Discount and Other	279,563				234,353				120,974
Standardized Measure of Discounted Future Net Cash Flows at End of Year	$	2,066,878			$	1,966,366			$	1,469,791

Valuation_And_Qualifying_Accou

Valuation And Qualifying Accounts	12 Months Ended
	Sep. 30, 2014
Valuation and Qualifying Accounts [Abstract]	'
Valuation And Qualifying Accounts	'
	Schedule II — Valuation and Qualifying Accounts
	Description	Balance at Beginning of Period		Additions Charged to Costs and Expenses		Additions Charged to Other Accounts(1)		Deductions (2)		Balance at End of Period
	Year Ended September 30, 2014
	Allowance for Uncollectible Accounts	$	27,144	$	10,856	$	3,241	$	9,430	$	31,811
	Year Ended September 30, 2013
	Allowance for Uncollectible Accounts	$	30,317	$	5,568	$	2,390	$	11,131	$	27,144
	Year Ended September 30, 2012
	Allowance for Uncollectible Accounts	$	31,039	$	9,183	$	1,946	$	11,851	$	30,317
	-1	Represents the discount on accounts receivable purchased in accordance with the Utility segment’s 2005 New York rate agreement.
	-2	Amounts represent net accounts receivable written-off.

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Principles Of Consolidation	'
	Principles of Consolidation
	The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to oil and gas producing properties accounted for under the full cost method of accounting.
	The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Regulation	'
	Regulation
	The Company is subject to regulation by certain state and federal authorities. The Company has accounting policies which conform to GAAP, as applied to regulated enterprises, and are in accordance with the accounting requirements and ratemaking practices of the regulatory authorities. Reference is made to Note C — Regulatory Matters for further discussion.
Revenue Recognition	'
	Revenue Recognition
	The Company’s Exploration and Production segment records revenue based on entitlement, which means that revenue is recorded based on the actual amount of gas or oil that is delivered to a pipeline and the Company’s ownership interest in the producing well. If a production imbalance occurs between what was supposed to be delivered to a pipeline and what was actually produced and delivered, the Company accrues the difference as an imbalance.
	The Company’s Pipeline and Storage segment records revenue for natural gas transportation and storage services. Revenue from reservation charges on firm contracted capacity is recognized through equal monthly charges over the contract period regardless of the amount of gas that is transported or stored. Commodity charges on firm contracted capacity and interruptible contracts are recognized as revenue when physical deliveries of natural gas are made at the agreed upon delivery point or when gas is injected or withdrawn from the storage field. The point of delivery into the pipeline or injection or withdrawal from storage is the point at which ownership and risk of loss transfers to the buyer of such transportation and storage services.
	In the Company’s Gathering segment, revenue is recorded at the point at which gathered volumes are delivered into interstate pipelines.
	The Company’s Utility segment records revenue for gas sales and transportation in the period that gas is delivered to customers. This includes the recording of receivables for gas delivered but not yet billed to customers based on the Company's estimate of the amount of gas delivered between the last meter reading date and the end of the accounting period. Such receivables are a component of Unbilled Revenue on the Consolidated Balance Sheets.
	The Company’s Energy Marketing segment records revenue for gas sales in the period that gas is delivered to customers. This includes the recording of receivables for gas delivered but not yet billed to customers based on the Company's estimate of the amount of gas delivered between the last meter reading date and the end of the accounting period. Such receivables are a component of Unbilled Revenue on the Consolidated Balance Sheets.
Allowance For Uncollectible Accounts	'
	Allowance for Uncollectible Accounts
	The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is determined based on historical experience, the age and other specific information about customer accounts. Account balances are charged off against the allowance twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered.
Regulatory Mechanisms	'
	Regulatory Mechanisms
	The Company’s rate schedules in the Utility segment contain clauses that permit adjustment of revenues to reflect price changes from the cost of purchased gas included in base rates. Differences between amounts currently recoverable and actual adjustment clause revenues, as well as other price changes and pipeline and storage company refunds not yet includable in adjustment clause rates, are deferred and accounted for as either unrecovered purchased gas costs or amounts payable to customers. Such amounts are generally recovered from (or passed back to) customers during the following fiscal year.
	Estimated refund liabilities to ratepayers represent management’s current estimate of such refunds. Reference is made to Note C — Regulatory Matters for further discussion.
	The impact of weather on revenues in the Utility segment’s New York rate jurisdiction is tempered by a WNC, which covers the eight-month period from October through May. The WNC is designed to adjust the rates of retail customers to reflect the impact of deviations from normal weather. Weather that is warmer than normal results in a surcharge being added to customers’ current bills, while weather that is colder than normal results in a refund being credited to customers’ current bills. Since the Utility segment’s Pennsylvania rate jurisdiction does not have a WNC, weather variations have a direct impact on the Pennsylvania rate jurisdiction’s revenues.
	The impact of weather normalized usage per customer account in the Utility segment’s New York rate jurisdiction is tempered by a revenue decoupling mechanism. The effect of the revenue decoupling mechanism is to render the Company financially indifferent to throughput decreases resulting from conservation. Weather normalized usage per account that exceeds the average weather normalized usage per customer account results in a refund being credited to customers’ bills. Weather normalized usage per account that is below the average weather normalized usage per account results in a surcharge being added to customers’ bills. The surcharge or credit is calculated over a twelve-month period ending December 31st, and applied to customer bills annually, beginning March 1st.
	In the Pipeline and Storage segment, the allowed rates that Supply Corporation and Empire bill their customers are based on a straight fixed-variable rate design, which allows recovery of all fixed costs, including return on equity and income taxes, through fixed monthly reservation charges. Because of this rate design, changes in throughput due to weather variations do not have a significant impact on the revenues of Supply Corporation or Empire.
Property, Plant And Equipment	'
	Property, Plant and Equipment
	In the Company’s Exploration and Production segment, oil and gas property acquisition, exploration and development costs are capitalized under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of oil and gas properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and gas attributable to a cost center. For further discussion of capitalized costs, refer to Note M — Supplementary Information for Oil and Gas Producing Activities.
	Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying prices of oil and gas (as adjusted for hedging) to estimated future production of proved oil and gas reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unevaluated properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The natural gas and oil prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent impairment is required to be charged to earnings in that quarter. In adjusting estimated future net cash flows for hedging under the ceiling test at September 30, 2014, 2013, and 2012, estimated future net cash flows were decreased by $33.6 million and increased by $71.6 million and $128.4 million, respectively. At September 30, 2014, the ceiling exceeded the book value of the oil and gas properties by approximately $148.4 million.
	The principal assets of the Utility and Pipeline and Storage segments, consisting primarily of gas plant in service, are recorded at the historical cost when originally devoted to service.
	Maintenance and repairs of property and replacements of minor items of property are charged directly to maintenance expense. The original cost of the regulated subsidiaries’ property, plant and equipment retired, and the cost of removal less salvage, are charged to accumulated depreciation.
Depreciation, Depletion And Amortization	'
	Depreciation, Depletion and Amortization
	For oil and gas properties, depreciation, depletion and amortization is computed based on quantities produced in relation to proved reserves using the units of production method. The cost of unproved oil and gas properties is excluded from this computation. In the All Other category, for timber properties, depletion, determined on a property by property basis, is charged to operations based on the actual amount of timber cut in relation to the total amount of recoverable timber. For all other property, plant and equipment, depreciation and amortization is computed using the straight-line method in amounts sufficient to recover costs over the estimated service lives of property in service. The following is a summary of depreciable plant by segment:
		As of September 30
		2014				2013
		(Thousands)
	Exploration and Production	$	3,996,834			$	3,437,767
	Pipeline and Storage	1,609,593				1,547,192
	Gathering	239,507				130,082
	Utility	1,833,104				1,778,140
	Energy Marketing	3,366				3,460
	All Other and Corporate	108,986				109,690
		$	7,791,390			$	7,006,331
	Average depreciation, depletion and amortization rates are as follows:
		Year Ended September 30
		2014				2013			2012
	Exploration and Production, per Mcfe(1)	$	1.85			$	2.02		$	2.25
	Pipeline and Storage	2.4		%		2.5		%	2.9		%
	Gathering	3.3		%		3.7		%	3.3		%
	Utility	2.6		%		2.6		%	2.6		%
	Energy Marketing	5.8		%		3.9		%	3.6		%
	All Other and Corporate	0.9		%		1.3		%	1.1		%
	-1	Amounts include depletion of oil and gas producing properties as well as depreciation of fixed assets. As disclosed in Note M — Supplementary Information for Oil and Gas Producing Properties, depletion of oil and gas producing properties amounted to $1.82, $1.98 and $2.19 per Mcfe of production in 2014, 2013 and 2012, respectively.
Goodwill	'
	Goodwill
	The Company has recognized goodwill of $5.5 million as of September 30, 2014 and 2013 on its Consolidated Balance Sheets related to the Company’s acquisition of Empire in 2003. The Company accounts for goodwill in accordance with the current authoritative guidance, which requires the Company to test goodwill for impairment annually. At September 30, 2014, 2013 and 2012, the fair value of Empire was greater than its book value. As such, the goodwill was not considered impaired at those dates. Going back to the origination of the goodwill in 2003, the Company has never recorded an impairment of its goodwill balance.
Financial Instruments	'
	Financial Instruments
	Unrealized gains or losses from the Company’s investments in an equity mutual fund and the stock of an insurance company (securities available for sale) are recorded as a component of accumulated other comprehensive income (loss). Reference is made to Note G — Financial Instruments for further discussion.
	The Company uses a variety of derivative financial instruments to manage a portion of the market risk associated with fluctuations in the price of natural gas and crude oil. These instruments include price swap agreements and futures contracts. The Company accounts for these instruments as either cash flow hedges or fair value hedges. In both cases, the fair value of the instrument is recognized on the Consolidated Balance Sheets as either an asset or a liability labeled Fair Value of Derivative Financial Instruments. Reference is made to Note F — Fair Value Measurements for further discussion concerning the fair value of derivative financial instruments.
	For effective cash flow hedges, the offset to the asset or liability that is recorded is a gain or loss recorded in accumulated other comprehensive income (loss) on the Consolidated Balance Sheets. The gain or loss recorded in accumulated other comprehensive income (loss) remains there until the hedged transaction occurs, at which point the gains or losses are reclassified to operating revenues or purchased gas expense on the Consolidated Statements of Income. Reference is made to Note G - Financial Instruments for further discussion concerning cash flow hedges.
	For fair value hedges, the offset to the asset or liability that is recorded is a gain or loss recorded to operating revenues or purchased gas expense on the Consolidated Statements of Income. However, in the case of fair value hedges, the Company also records an asset or liability on the Consolidated Balance Sheets representing the change in fair value of the asset or firm commitment that is being hedged (see Other Current Assets section in this footnote). The offset to this asset or liability is a gain or loss recorded to operating revenues or purchased gas expense on the Consolidated Statements of Income as well. If the fair value hedge is effective, the gain or loss from the derivative financial instrument is offset by the gain or loss that arises from the change in fair value of the asset or firm commitment that is being hedged.
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	The components of Accumulated Other Comprehensive Income (Loss) and changes for the year ended September 30, 2014, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands):
		Gains and Losses on Derivative Financial Instruments				Gains and Losses on Securities Available for Sale			Funded Status of the Pension and Other Post-Retirement Benefit Plans			Total
	Year Ended September 30, 2014
	Balance at October 1, 2013	$	30,722			$	6,337		$	(56,293	)	$	(19,234	)
	Other Comprehensive Gains and Losses Before Reclassifications	4,805				2,465			(5,560		)	1,710
	Amounts Reclassified From Other Comprehensive Loss	8,132				(420		)	5,833			13,545
	Balance at September 30, 2014	$	43,659			$	8,382		$	(56,020	)	$	(3,979	)
	The amounts included in accumulated other comprehensive income (loss) related to the funded status of the Company’s pension and other post-retirement benefit plans consist of prior service costs and accumulated losses. The total amount for prior service credit was $0.2 million and $0.3 million at September 30, 2014 and 2013, respectively. The total amount for accumulated losses was $56.2 million and $56.6 million at September 30, 2014 and 2013, respectively.
Reclassifications Out Of Accumulated Other Comprehensive Loss	'
	Reclassifications Out of Accumulated Other Comprehensive Loss
	The details about the reclassification adjustments out of accumulated other comprehensive loss for the year ended September 30, 2014 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands):
	Details About Accumulated Other		Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Loss for the				Affected Line Item in the Statement Where Net Income is Presented
	Comprehensive Loss Components		Year Ended
			30-Sep-14
	Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges:
	Commodity Contracts			($14,880	)		Operating Revenues
	Commodity Contracts		(2,767		)		Purchased Gas
	Gains (Losses) on Securities Available for Sale		662				Other Income
	Amortization of Prior Year Funded Status of the Pension and Other Post-Retirement Benefit Plans:
	Prior Service Credit		131				-1
	Net Actuarial Loss		(9,334		)		-1
			(26,188		)		Total Before Income Tax
			12,643				Income Tax Expense
				($13,545	)		Net of Tax
	-1	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note H — Retirement Plan and Other Post-Retirement Benefits for additional details.
Gas Stored Underground - Current	'
	Gas Stored Underground — Current
	In the Utility segment, gas stored underground — current in the amount of $25.3 million is carried at lower of cost or market, on a LIFO method. Based upon the average price of spot market gas purchased in September 2014, including transportation costs, the current cost of replacing this inventory of gas stored underground — current exceeded the amount stated on a LIFO basis by approximately $33.2 million at September 30, 2014. All other gas stored underground — current, which is in the Energy Marketing segment, is carried at an average cost method, subject to lower of cost or market adjustments.
Unamortized Debt Expense	'
	Unamortized Debt Expense
	Costs associated with the issuance of debt by the Company are deferred and amortized over the lives of the related debt.
	Costs associated with the reacquisition of debt related to rate-regulated subsidiaries are deferred and amortized over the remaining life of the issue or the life of the replacement debt in order to match regulatory treatment. At September 30, 2014, the remaining weighted average amortization period for such costs was approximately 5 years.
Income Taxes	'
	Income Taxes
	The Company and its subsidiaries file a consolidated federal income tax return. State tax returns are filed on a combined or separate basis depending on the applicable laws in the jurisdictions where tax returns are filed. Investment tax credit, prior to its repeal in 1986, was deferred and is being amortized over the estimated useful lives of the related property, as required by regulatory authorities having jurisdiction.
	The Company reports a liability or a reduction of deferred tax assets for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company recognizes interest relating to uncertain tax positions in Other Interest Expense and penalties in Other Income.
Consolidated Statements Of Cash Flows	'
	Consolidated Statement of Cash Flows
	For purposes of the Consolidated Statement of Cash Flows, the Company considers all highly liquid debt instruments purchased with a maturity of generally three months or less to be cash equivalents.
Hedging Collateral Deposits	'
	Hedging Collateral Deposits
	This is an account title for cash held in margin accounts funded by the Company to serve as collateral for hedging positions. In accordance with its accounting policy, the Company does not offset hedging collateral deposits paid or received against related derivative financial instrument liability or asset balances.
Other Current Assets	'
	Other Current Assets
	The components of the Company’s Other Current Assets are as follows:
		Year Ended September 30
		2014				2013
		(Thousands)
	Prepayments	$	10,079			$	10,605
	Prepaid Property and Other Taxes	13,743				13,079
	Federal Income Taxes Receivable	8,211				1,122
	State Income Taxes Receivable	—				3,275
	Fair Values of Firm Commitments	—				1,829
	Regulatory Assets	22,719				26,995
		$	54,752			$	56,905
Other Accruals And Current Liabilities	'
	Other Accruals and Current Liabilities
	The components of the Company’s Other Accruals and Current Liabilities are as follows:
		Year Ended September 30
		2014				2013
		(Thousands)
	Accrued Capital Expenditures	$	80,348			$	41,100
	Regulatory Liabilities	18,072				20,013
	State Income Taxes Payable	5,798				—
	Other	32,454				22,833
		$	136,672			$	83,946
Customer Advances	'
	Customer Advances
	The Company’s Utility and Energy Marketing segments have balanced billing programs whereby customers pay their estimated annual usage in equal installments over a twelve-month period. Monthly payments under the balanced billing programs are typically higher than current month usage during the summer months. During the winter months, monthly payments under the balanced billing programs are typically lower than current month usage.
Customer Security Deposits	'
	Customer Security Deposits
	The Company, in its Utility, Pipeline and Storage, and Energy Marketing segments, often times requires security deposits from marketers, producers, pipeline companies, and commercial and industrial customers before providing services to such customers.
Earnings Per Common Share	'
	Earnings Per Common Share
	Basic earnings per common share is computed by dividing income available for common stock by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For purposes of determining earnings per common share, the only potentially dilutive securities the Company has outstanding are stock options, SARs, restricted stock units and performance shares. The diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. Stock options, SARs, restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company has various stock option and stock award plans which provide or provided for the issuance of one or more of the following to key employees: incentive stock options, nonqualified stock options, SARs, restricted stock, restricted stock units, performance units or performance shares. The Company follows authoritative guidance which requires the measurement and recognition of compensation cost at fair value for all share-based payments. Stock options and SARs under all plans have exercise prices equal to the average market price of Company common stock on the date of grant, and generally no stock option or SAR is exercisable less than one year or more than ten years after the date of each grant. The Company has chosen the Black-Scholes-Merton closed form model to calculate the compensation expense associated with stock options and SARs.
	Restricted stock is subject to restrictions on vesting and transferability. Restricted stock awards entitle the participants to full dividend and voting rights. The market value of restricted stock on the date of the award is recorded as compensation expense over the vesting period. Certificates for shares of restricted stock awarded under the Company’s stock option and stock award plans are held by the Company during the periods in which the restrictions on vesting are effective. Restrictions on restricted stock awards generally lapse ratably over a period of not more than ten years after the date of each grant. Restricted stock units also are subject to restrictions on vesting and transferability. Restricted stock units, both performance and non-performance based, represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. The performance based and non-performance based restricted stock units do not entitle the participants to dividend and voting rights. The accounting for performance based and non-performance based restricted stock units is the same as the accounting for restricted share awards, except that the fair value at the date of grant of the restricted stock units (represented by the market value of Company common stock on the date of the award) must be reduced by the present value of forgone dividends over the vesting term of the award. The fair value of restricted stock units on the date of award is recorded as compensation expense over the vesting period.
	Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied. Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period. For performance shares based on a return on capital goal, the fair value at the date of grant of the performance shares is determined by multiplying the expected number of performance shares to be issued by the market value of Company common stock on the date of grant reduced by the present value of forgone dividends. For performance shares based on a total shareholder return goal, the Company uses the Monte Carlo simulation technique to estimate the fair value price at the date of grant.
New Authoritative Accounting And Financial Reporting Guidance	'
	New Authoritative Accounting and Financial Reporting Guidance
	In May 2014, the FASB issued authoritative guidance regarding revenue recognition. The authoritative guidance provides a single, comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. This authoritative guidance will be effective as of the Company's first quarter of fiscal 2018 and early adoption is not permitted. The Company is currently evaluating the impact that adoption of this guidance will have on its consolidated financial statements and disclosures.
	In June 2014, the FASB issued authoritative guidance regarding accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the employee has completed the requisite service period. This authoritative guidance requires that such performance targets that affect vesting be treated as performance conditions, meaning that the performance target should not be factored in the calculation of the award at the grant date. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved. This authoritative guidance will be effective as of the Company's first quarter of fiscal 2017, with early adoption permitted. The Company is currently evaluating the impact that adoption of this guidance will have on its consolidated financial statements.

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Schedule Of Depreciable Plant By Segment	'
	The following is a summary of depreciable plant by segment:
		As of September 30
		2014				2013
		(Thousands)
	Exploration and Production	$	3,996,834			$	3,437,767
	Pipeline and Storage	1,609,593				1,547,192
	Gathering	239,507				130,082
	Utility	1,833,104				1,778,140
	Energy Marketing	3,366				3,460
	All Other and Corporate	108,986				109,690
		$	7,791,390			$	7,006,331
Average Depreciation Depletion And Amortization Rates	'
	Average depreciation, depletion and amortization rates are as follows:
		Year Ended September 30
		2014				2013			2012
	Exploration and Production, per Mcfe(1)	$	1.85			$	2.02		$	2.25
	Pipeline and Storage	2.4		%		2.5		%	2.9		%
	Gathering	3.3		%		3.7		%	3.3		%
	Utility	2.6		%		2.6		%	2.6		%
	Energy Marketing	5.8		%		3.9		%	3.6		%
	All Other and Corporate	0.9		%		1.3		%	1.1		%
	-1	Amounts include depletion of oil and gas producing properties as well as depreciation of fixed assets. As disclosed in Note M — Supplementary Information for Oil and Gas Producing Properties, depletion of oil and gas producing properties amounted to $1.82, $1.98 and $2.19 per Mcfe of production in 2014, 2013 and 2012, respectively.
Components Of Accumulated Other Comprehensive Income (Loss)	'
	The components of Accumulated Other Comprehensive Income (Loss) and changes for the year ended September 30, 2014, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands):
		Gains and Losses on Derivative Financial Instruments				Gains and Losses on Securities Available for Sale			Funded Status of the Pension and Other Post-Retirement Benefit Plans			Total
	Year Ended September 30, 2014
	Balance at October 1, 2013	$	30,722			$	6,337		$	(56,293	)	$	(19,234	)
	Other Comprehensive Gains and Losses Before Reclassifications	4,805				2,465			(5,560		)	1,710
	Amounts Reclassified From Other Comprehensive Loss	8,132				(420		)	5,833			13,545
	Balance at September 30, 2014	$	43,659			$	8,382		$	(56,020	)	$	(3,979	)
Schedule Of Reclassifications Out Of Accumulated Other Comprehensive Loss	'
	The details about the reclassification adjustments out of accumulated other comprehensive loss for the year ended September 30, 2014 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands):
	Details About Accumulated Other		Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Loss for the				Affected Line Item in the Statement Where Net Income is Presented
	Comprehensive Loss Components		Year Ended
			30-Sep-14
	Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges:
	Commodity Contracts			($14,880	)		Operating Revenues
	Commodity Contracts		(2,767		)		Purchased Gas
	Gains (Losses) on Securities Available for Sale		662				Other Income
	Amortization of Prior Year Funded Status of the Pension and Other Post-Retirement Benefit Plans:
	Prior Service Credit		131				-1
	Net Actuarial Loss		(9,334		)		-1
			(26,188		)		Total Before Income Tax
			12,643				Income Tax Expense
				($13,545	)		Net of Tax
	-1	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note H — Retirement Plan and Other Post-Retirement Benefits for additional details.
Schedule Of Other Current Assets	'
	The components of the Company’s Other Current Assets are as follows:
		Year Ended September 30
		2014				2013
		(Thousands)
	Prepayments	$	10,079			$	10,605
	Prepaid Property and Other Taxes	13,743				13,079
	Federal Income Taxes Receivable	8,211				1,122
	State Income Taxes Receivable	—				3,275
	Fair Values of Firm Commitments	—				1,829
	Regulatory Assets	22,719				26,995
		$	54,752			$	56,905
Schedule of Other Accruals And Current Liabilities	'
	The components of the Company’s Other Accruals and Current Liabilities are as follows:
		Year Ended September 30
		2014				2013
		(Thousands)
	Accrued Capital Expenditures	$	80,348			$	41,100
	Regulatory Liabilities	18,072				20,013
	State Income Taxes Payable	5,798				—
	Other	32,454				22,833
		$	136,672			$	83,946

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation [Abstract]	'
Schedule Of Change In Asset Retirement Obligation	'
	A reconciliation of the Company’s asset retirement obligations are shown below:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Balance at Beginning of Year	$	119,511		$	119,246		$	75,731
	Liabilities Incurred and Revisions of Estimates	(2,496		)	(4,796		)	41,653
	Liabilities Settled	(6,955		)	(1,744		)	(2,997		)
	Accretion Expense	7,653			6,805			4,859
	Balance at End of Year	$	117,713		$	119,511		$	119,246

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Sep. 30, 2014
Regulatory Assets and Liabilities, Other Disclosures [Abstract]	'
Schedule Of Regulatory Assets And Liabilities	'
	The Company has recorded the following regulatory assets and liabilities:
		At September 30
		2014			2013
		(Thousands)
	Regulatory Assets(1):
	Pension Costs(2) (Note H)	$	164,804		$	187,181
	Post-Retirement Benefit Costs(2) (Note H)	17,128			29,838
	Recoverable Future Taxes (Note D)	163,485			163,355
	Environmental Site Remediation Costs(2) (Note I)	25,645			18,104
	NYPSC Assessment(3)	12,730			13,169
	Asset Retirement Obligations(2) (Note B)	12,006			11,837
	Unamortized Debt Expense (Note A)	2,747			3,276
	Other(4)	14,842			19,434
	Total Regulatory Assets	413,387			446,194
	Less: Amounts Included in Other Current Assets	(22,719		)	(26,995		)
	Total Long-Term Regulatory Assets	$	390,668		$	419,199
		At September 30
		2014			2013
		(Thousands)
	Regulatory Liabilities:
	Cost of Removal Regulatory Liability	$	173,199		$	157,622
	Taxes Refundable to Customers (Note D)	91,736			85,655
	Post-Retirement Benefit Costs (Note H)	53,650			37,923
	Amounts Payable to Customers (See Regulatory Mechanisms in Note A)	33,745			12,828
	Off-System Sales and Capacity Release Credits(5)	12,805			10,228
	Other(6)	32,769			33,411
	Total Regulatory Liabilities	397,904			337,667
	Less: Amounts included in Current and Accrued Liabilities	(51,817		)	(32,841		)
	Total Long-Term Regulatory Liabilities	$	346,087		$	304,826
	-1	The Company recovers the cost of its regulatory assets but generally does not earn a return on them. There are a few exceptions to this rule. For example, the Company does earn a return on Unrecovered Purchased Gas Costs and, in the New York jurisdiction of its Utility segment, earns a return, within certain parameters, on the excess of cumulative funding to the pension plan over the cumulative amount collected in rates.
	-2	Included in Other Regulatory Assets on the Consolidated Balance Sheets.
	-3	Amounts are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be recovered from ratepayers in the next 12 months.
	-4	$9,989 and $13,826 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $4,853 and $5,608 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.
	-5	Amounts are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be passed back to ratepayers in the next 12 months.
	-6	$5,267 and $9,785 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $27,502 and $23,626 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Components Of Federal And State Income Taxes Included In The Consolidated Statements Of Income	'
	The components of federal and state income taxes included in the Consolidated Statements of Income are as follows:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Current Income Taxes —
	Federal	$	34,579		$	(632	)	$	(8	)
	State	12,620			5,503			6,412
	Deferred Income Taxes —
	Federal	116,143			130,318			111,176
	State	26,272			37,569			32,974
		189,614			172,758			150,554
	Deferred Investment Tax Credit	(434		)	(426		)	(581		)
	Total Income Taxes	$	189,180		$	172,332		$	149,973
	Presented as Follows:
	Other Income	$	(434	)	$	(426	)	$	(581	)
	Income Tax Expense	189,614			172,758			150,554
	Total Income Taxes	$	189,180		$	172,332		$	149,973
Schedule Of Income Tax Reconciliation By Applying Federal Income Tax Rate	'
	The following is a reconciliation of this difference:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	U.S. Income Before Income Taxes	$	488,593		$	432,333		$	370,050
	Income Tax Expense, Computed at U.S. Federal Statutory Rate of 35%	$	171,008		$	151,317		$	129,518
	Increase (Reduction) in Taxes Resulting from:
	State Income Taxes	25,280			27,997			25,601
	Miscellaneous	(7,108		)	(6,982		)	(5,146		)
	Total Income Taxes	$	189,180		$	172,332		$	149,973
Significant Components Of Deferred Tax Liabilities And Assets	'
	Significant components of the Company’s deferred tax liabilities and assets were as follows:
		At September 30
		2014			2013
		(Thousands)
	Deferred Tax Liabilities:
	Property, Plant and Equipment	$	1,614,515		$	1,504,187
	Pension and Other Post-Retirement Benefit Costs	113,248			124,021
	Other	87,935			75,419
	Total Deferred Tax Liabilities	1,815,698			1,703,627
	Deferred Tax Assets:
	Pension and Other Post-Retirement Benefit Costs	(124,452		)	(130,256		)
	Tax Loss and Credit Carryforwards	(171,423		)	(215,262		)
	Other	(103,863		)	(90,461		)
	Total Deferred Tax Assets	(399,738		)	(435,979		)
	Total Net Deferred Income Taxes	$	1,415,960		$	1,267,648
	Presented as Follows:
	Deferred Tax Liability/(Asset) — Current	$	(40,323	)	$	(79,359	)
	Deferred Tax Liability — Non-Current	1,456,283			1,347,007
	Total Net Deferred Income Taxes	$	1,415,960		$	1,267,648
Reconciliation Of The Change In Unrecognized Tax Benefits	'
	The following is a reconciliation of the change in unrecognized tax benefits:
		Year Ended September 30
		2014			2013			2012
		(Thousands)
	Balance at Beginning of Year	$	2,001		$	11,170		$	7,766
	Additions for Tax Positions Related to Current Year	—			700			1,600
	Additions for Tax Positions of Prior Years	2,447			164			2,751
	Reductions for Tax Positions of Prior Years	(1,301		)	(10,033		)	(947		)
	Balance at End of Year	$	3,147		$	2,001		$	11,170

Capitalization_And_ShortTerm_B1

Capitalization And Short-Term Borrowings (Tables)	12 Months Ended
	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary Of Changes In Common Stock Equity	'
	Summary of Changes in Common Stock Equity
									Paid In				Earnings				Accumulated
		Common Stock							Capital				Reinvested				Other
													in the				Comprehensive
													Business				Income
		Shares			Amount												(Loss)
		(Thousands, except per share amounts)
	Balance at September 30, 2011	82,813			$	82,813			$	650,749			$	1,206,022			$	(47,699	)
	Net Income Available for Common Stock												220,077
	Dividends Declared on Common Stock ($1.44 Per Share)												(119,815		)
	Other Comprehensive Loss, Net of Tax																(51,321		)
	Share-Based Payment Expense(2)								7,156
	Common Stock Issued Under Stock and Benefit Plans(1)	517			517				11,596
	Balance at September 30, 2012	83,330			83,330				669,501				1,306,284				(99,020		)
	Net Income Available for Common Stock												260,001
	Dividends Declared on Common Stock ($1.48 Per Share)												(123,668		)
	Other Comprehensive Income, Net of Tax																79,786
	Share-Based Payment Expense(2)								11,537
	Common Stock Issued Under Stock and Benefit Plans(1)	332			332				6,646
	Balance at September 30, 2013	83,662			83,662				687,684				1,442,617				(19,234		)
	Net Income Available for Common Stock												299,413
	Dividends Declared on Common Stock ($1.52 Per Share)												(127,669		)
	Other Comprehensive Income, Net of Tax																15,255
	Share-Based Payment Expense(2)								10,654
	Common Stock Issued Under Stock and Benefit Plans(1)	495			495				17,806
	Balance at September 30, 2014	84,157			$	84,157			$	716,144			$	1,614,361		-3	$	(3,979	)
	-1	Paid in Capital includes tax benefits of $4.6 million, $0.7 million and $1.0 million for September 30, 2014, 2013 and 2012, respectively, related to stock-based compensation.
	-2	Paid in Capital includes compensation costs associated with stock option, SARs, performance share and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.
	-3	The availability of consolidated earnings reinvested in the business for dividends payable in cash is limited under terms of the indentures covering long-term debt. At September 30, 2014, $1.5 billion of accumulated earnings was free of such limitations.
Schedule Of Share-Based Compensation For Stock Options	'
	Transactions involving option shares for all plans are summarized as follows:
		Number of			Weighted				Weighted		Aggregate
		Shares Subject			Average				Average		Intrinsic
		to Option			Exercise Price				Remaining		Value
									Contractual
									Life (Years)
											(In thousands)
	Outstanding at September 30, 2013	803,500			$	34.71
	Granted in 2014	—			$	—
	Exercised in 2014	(321,500	)		$	31.71
	Forfeited in 2014	—			$	—
	Outstanding at September 30, 2014	482,000			$	36.71			1.8		$	16,039
	Option shares exercisable at September 30, 2014	482,000			$	36.71			1.8		$	16,039
	Option shares available for future grant at September 30, 2014(1)	712,232
	-1	Includes shares available for SARs, restricted stock and performance share grants.
Schedule Of Share-Based Compensation For SARs	'
	Transactions involving SARs for all plans are summarized as follows:
		Number of			Weighted				Weighted		Aggregate
		Shares Subject			Average				Average		Intrinsic
		To Option			Exercise Price				Remaining		Value
									Contractual
									Life (Years)
											(In thousands)
	Outstanding at September 30, 2013	2,002,704			$	46.73
	Granted in 2014	—			$	—
	Exercised in 2014	(209,222	)		$	34.9
	Forfeited in 2014	—			$	—
	Canceled in 2014	—			$	—
	Outstanding at September 30, 2014	1,793,482			$	48.11			5.93		$	39,246
	SARs exercisable at September 30, 2014	1,434,023			$	46.65			5.45		$	33,466
Schedule Of Share-Based Compensation For Restricted Share Awards	'
	Transactions involving restricted share awards for all plans are summarized as follows:
		Number of			Weighted Average
		Restricted			Fair Value per
		Share Awards			Award
	Outstanding at September 30, 2013	127,453			$	51.69
	Granted in 2014	—			$	—
	Vested in 2014	(34,601	)		$	58.17
	Forfeited in 2014	(3,334	)		$	55.09
	Outstanding at September 30, 2014	89,518			$	49.05
Schedule Of Share-Based Compensation For Non-Performance Based Restricted Stock Units	'
	Transactions involving non-performance based restricted stock units for all plans are summarized as follows:
		Number of			Weighted Average
		Restricted			Fair Value per
		Stock Units			Award
	Outstanding at September 30, 2013	143,500			$	51.53
	Granted in 2014	82,151			$	65.24
	Vested in 2014	(12,432	)		$	60.54
	Forfeited in 2014	(8,700	)		$	54.53
	Outstanding at September 30, 2014	204,519			$	56.36
Schedule Of Share-Based Compensation For Performance Based Restricted Stock Units	'
	Transactions involving performance based restricted stock units for all plans are summarized as follows:
		Number of Performance Based			Weighted Average
		Restricted Stock Units			Fair Value per
					Award
	Outstanding at September 30, 2013	255,604			$	49.51
	Granted in 2014	—			$	—
	Vested in 2014	—			$	—
	Forfeited in 2014	(21,728	)		$	48.49
	Outstanding at September 30, 2014	233,876			$	49.61
Schedule of Share-based Compensation for Performance Shares	'
	Transactions involving performance shares for all plans are summarized as follows:
		Number of			Weighted Average
		Performance			Fair Value per
		Shares			Award
	Outstanding at September 30, 2013	—			$	—
	Granted in 2014	116,090			$	67.16
	Vested in 2014	—			$	—
	Forfeited in 2014	(17,624	)		$	67.16
	Outstanding at September 30, 2014	98,466			$	67.16
Schedule Of Long-Term Debt	'
	The outstanding long-term debt is as follows:
		At September 30
		2014				2013
		(Thousands)
	Medium-Term Notes(1):
	7.4% due March 2023 to June 2025	$	99,000			$	99,000
	Notes(1)(3):
	3.75% to 8.75% due April 2018 to March 2023	1,550,000				1,550,000
	Total Long-Term Debt	1,649,000				1,649,000
	Less Current Portion(2)	—				—
		$	1,649,000			$	1,649,000
	-1	The Medium-Term Notes and Notes are unsecured.
	-2	None of the Company’s long-term debt at September 30, 2014 and 2013 will mature within the following twelve-month period.
	-3	The holders of these notes may require the Company to repurchase their notes at a price equal to 101% of the principal amount in the event of both a change in control and a ratings downgrade to a rating below investment grade.
Performance Shares [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Schedule of Weighted Average Assumptions Used in Estimating Fair Value	'
	The following assumptions were used in estimating the fair value of the TSR performance shares at the date of grant:
		Year Ended September 30
		2014			2013		2012
	Risk-Free Interest Rate	0.62	%		N/A		N/A
	Remaining Term at Date of Grant (Years)	2.78			N/A		N/A
	Expected Volatility	28.3	%		N/A		N/A
	Expected Dividend Yield (Quarterly)	N/A			N/A		N/A
Stock Appreciation Rights (SARs) [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Schedule of Weighted Average Assumptions Used in Estimating Fair Value	'
	The following weighted average assumptions were used in estimating the fair value of SARs at the date of grant:
		Year Ended September 30
		2014		2013			2012
	Risk-Free Interest Rate	N/A		1.55	%		1.59	%
	Expected Life (Years)	N/A		8.25			8.25
	Expected Volatility	N/A		25.61	%		24.97	%
	Expected Dividend Yield (Quarterly)	N/A		0.69	%		0.64	%

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following table sets forth, by level within the fair value hierarchy, the Company’s financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of September 30, 2014 and 2013. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The fair value presentation for over the counter swaps has been changed to combine gas and oil swaps at both September 30, 2014 and September 30, 2013. In the September 30, 2013 Form 10-K, gas swaps were reported separately from oil swaps. This change in presentation was made because a significant number of the counterparties enter into both gas and oil swap agreements with the Company.
		At Fair Value as of September 30, 2014
	Recurring Fair Value Measures	Level 1			Level 2			Level 3			Netting			Total(1)
											Adjustments(1)
		(Dollars in thousands)
	Assets:
	Cash Equivalents — Money Market Mutual Funds	$	23,794		$	—		$	—		$	—		$	23,794
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	2,725			—			—			(1,987		)	738
	Over the Counter Swaps — Gas and Oil	—			75,951			1,368			(5,451		)	71,868
	Other Investments:
	Balanced Equity Mutual Fund	35,331			—			—			—			35,331
	Common Stock — Financial Services Industry	6,629			—			—			—			6,629
	Other Common Stock	455			—			—			—			455
	Hedging Collateral Deposits	2,734			—			—			—			2,734
	Total	$	71,668		$	75,951		$	1,368		$	(7,438	)	$	141,549
	Liabilities:
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	$	2,674		$	—		$	—		$	(1,987	)	$	687
	Over the Counter Swaps — Gas and Oil	—			5,523			—			(5,451		)	72
	Total	$	2,674		$	5,523		$	—		$	(7,438	)	$	759
	Total Net Assets/(Liabilities)	$	68,994		$	70,428		$	1,368		$	—		$	140,790
		At Fair Value as of September 30, 2013
	Recurring Fair Value Measures	Level 1			Level 2			Level 3			Netting			Total(1)
											Adjustments(1)
		(Dollars in thousands)
	Assets:
	Cash Equivalents — Money Market Mutual Funds	$	51,332		$	—		$	—		$	—		$	51,332
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	2,552			—			—			(1,641		)	911
	Over the Counter Swaps — Gas and Oil	—			57,070			—			(9,003		)	48,067
	Other Investments:
	Balanced Equity Mutual Fund	31,813			—			—			—			31,813
	Common Stock — Financial Services Industry	6,544			—			—			—			6,544
	Other Common Stock	330			—			—			—			330
	Hedging Collateral Deposits	1,094			—			—			—			1,094
	Total	$	93,665		$	57,070		$	—		$	(10,644	)	$	140,091
	Liabilities:
	Derivative Financial Instruments:
	Commodity Futures Contracts — Gas	$	1,641		$	—		$	—		$	(1,641	)	$	—
	Over the Counter Swaps — Gas and Oil	—			4,452			5,190			(9,003		)	639
	Total	$	1,641		$	4,452		$	5,190		$	(10,644	)	$	639
	Total Net Assets/(Liabilities)	$	92,024		$	52,618		$	(5,190	)	$	—		$	139,452
	-1	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.
Fair Value Measurements Using Unobservable Inputs (Level 3)	'
	All settlements of the derivative financial instruments are reflected in the Gains/Losses Realized and Included in Earnings column of the tables below (amounts in parentheses indicate credits in the derivative asset/liability accounts).
	Fair Value Measurements Using Unobservable Inputs (Level 3)
					Total Gains/Losses
		October 1,			(Gains)/Losses			Gains/(Losses)			Transfer			September 30,
		2013			Realized and			Unrealized and			In/(Out) of			2014
					Included in			Included in Other			Level 3
					Earnings			Comprehensive
								Income (Loss)
		(Dollars in thousands)
	Derivative Financial Instruments(2)	$	(5,190	)	$	2,217	-1	$	4,341		$	—		$	1,368
	-1	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2014.
	-2	Derivative Financial Instruments are shown on a net basis.
					Total Gains/Losses
		October 1,			(Gains)/Losses			Gains/(Losses)			Transfer			September 30,
		2012			Realized and			Unrealized and			In/(Out) of			2013
					Included in			Included in Other			Level 3
					Earnings			Comprehensive
								Income (Loss)
		(Dollars in thousands)
	Derivative Financial Instruments(2)	$	(19,664	)	$	13,408	-1	$	1,066		$	—		$	(5,190	)
	-1	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2013.
	-2	Derivative Financial Instruments are shown on a net basis.

Financial_Instruments_Tables

Financial Instruments (Tables)	12 Months Ended
	Sep. 30, 2014
Financial Instruments, Owned, at Fair Value [Abstract]	'
Long-Term Debt	'
	Based on these criteria, the fair market value of long-term debt, including current portion, was as follows:
		At September 30
		2014  Carrying				2014 Fair				2013 Carrying			2013 Fair
		Amount				Value				Amount			Value
		(Thousands)
	Long-Term Debt	$	1,649,000			$	1,775,715			$	1,649,000		$	1,767,519
Schedule Of Derivatives Financial Instruments Designated And Qualifying As Cash Flow Hedges On The Statements Of Financial Performance	'
	The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the
	Year Ended September 30, 2014 and 2013 (Dollar Amounts in Thousands)
	Derivatives in Cash		Amount of								Location of	Amount of						Location of	Derivative Gain or (Loss) Recognized in the Consolidated Statement of Income (Ineffective Portion and Amount Excluded from Effectiveness Testing) for the Year Ended September 30,
	Flow Hedging		Derivative Gain or								Derivative Gain or (Loss) Reclassified	Derivative Gain or						Derivative Gain or (Loss) Recognized
	Relationships		(Loss) Recognized								from Accumulated	(Loss) Reclassified						in the Consolidated
			in Other								Other Comprehensive	from Accumulated						Statement of Income
			Comprehensive								Income (Loss) on	Other						(Ineffective Portion
			Income (Loss) on								the Consolidated	Comprehensive						and Amount
			the Consolidated								Balance Sheet into	Income (Loss) on						Excluded from
			Statement of								the Consolidated	the Consolidated						Effectiveness Testing)
			Comprehensive								Statement of Income	Balance Sheet into
			Income (Loss)								(Effective Portion)	the Consolidated
			(Effective Portion)									Statement of Income
			for the Year Ended									(Effective Portion)
			September 30,									for the Year Ended
												September 30,
			2014				2013					2014			2013				2014		2013
	Commodity Contracts		$	9,763			$	87,813			Operating Revenue	$	(14,880	)	$	36,949		Operating Revenue	$	624	$	(2,045	)
	Commodity Contracts		$	(4,429	)		$	3,977			Purchased Gas	$	(2,767	)	$	(920	)	Not Applicable	$	—	$	—
	Total		$	5,334			$	91,790				$	(17,647	)	$	36,029			$	624	$	(2,045	)
Schedule Of Derivatives And Hedged Items In Fair Value Hedging Relationships	'
	For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting gain or loss on the hedged item attributable to the hedged risk completely offset each other in current earnings, as shown below.
	Derivatives in Fair Value Hedging Relationships		Location of Gain or (Loss) on Derivative and Hedged Item Recognized in the Consolidated Statement of Income		Amount of Gain  or				Amount of Gain  or
					(Loss) on Derivative				(Loss) on Hedged Item
					Recognized in the				Recognized in the
					Consolidated				Consolidated
					Statement of Income				Statement of Income
					for the Year Ended				for the Year Ended
					September 30, 2014				September 30, 2014
					(In thousands)
	Commodity Contracts		Operating Revenues		$	696			$	(696	)
	Commodity Contracts		Purchased Gas		(574		)		574
					$	122			$	(122	)

Retirement_Plan_And_Other_Post1

Retirement Plan And Other Post-Retirement Benefits (Tables)	12 Months Ended
	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]	'
Schedule Of Benefit Obligations, Plan Assets And Funded Status	'
		Retirement Plan											Other Post-Retirement Benefits
		Year Ended September 30											Year Ended September 30
		2014			2013				2012				2014				2013			2012
		(Thousands)
	Change in Benefit Obligation
	Benefit Obligation at Beginning of Period	$	946,305		$	1,070,744			$	949,777			$	460,634			$	561,263		$	485,452
	Service Cost	11,987			15,846				14,202				2,939				4,705			4,016
	Interest Cost	43,574			36,498				41,526				21,308				19,212			21,315
	Plan Participants’ Contributions	—			—				—				2,265				2,141			1,956
	Retiree Drug Subsidy Receipts	—			—				—				1,419				1,526			1,528
	Actuarial (Gain) Loss	53,887			(121,631		)		120,338				1,087				(104,455		)	71,708
	Benefits Paid	(56,254		)	(55,152		)		(55,099		)		(24,069		)		(23,758		)	(24,712		)
	Benefit Obligation at End of Period	$	999,499		$	946,305			$	1,070,744			$	465,583			$	460,634		$	561,263
	Change in Plan Assets
	Fair Value of Assets at Beginning of Period	$	799,307		$	701,676			$	601,719			$	472,392			$	414,134		$	351,990
	Actual Return on Plan Assets	93,238			98,783				111,034				44,898				61,715			63,552
	Employer Contributions	33,500			54,000				44,022				2,115				18,160			21,348
	Plan Participants’ Contributions	—			—				—				2,265				2,141			1,956
	Benefits Paid	(56,254		)	(55,152		)		(55,099		)		(24,069		)		(23,758		)	(24,712		)
	Fair Value of Assets at End of Period	$	869,791		$	799,307			$	701,676			$	497,601			$	472,392		$	414,134
	Net Amount Recognized at End of Period (Funded Status)	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	32,018			$	11,758		$	(147,129	)
	Amounts Recognized in the Balance Sheets Consist of:
	Non-Current Liabilities	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	(4,494	)		$	(11,016	)	$	(147,129	)
	Non-Current Assets	—			—				—				36,512				22,774			—
	Net Amount Recognized at End of Period	$	(129,708	)	$	(146,998	)		$	(369,068	)		$	32,018			$	11,758		$	(147,129	)
	Accumulated Benefit Obligation	$	940,068		$	886,942			$	986,223			N/A				N/A			N/A
	Weighted Average Assumptions Used to Determine Benefit Obligation at September 30
	Discount Rate	4.25		%	4.75		%		3.5		%		4.25		%		4.75		%	3.5		%
	Rate of Compensation Increase	4.75		%	4.75		%		4.75		%		4.75		%		4.75		%	4.75		%
		Retirement Plan											Other Post-Retirement Benefits
		Year Ended September 30											Year Ended September 30
		2014			2013				2012				2014				2013			2012
		(Thousands)
	Components of Net Periodic Benefit Cost
	Service Cost	$	11,987		$	15,846			$	14,202			$	2,939			$	4,705		$	4,016
	Interest Cost	43,574			36,498				41,526				21,308				19,212			21,315
	Expected Return on Plan Assets	(59,974		)	(57,346		)		(59,701		)		(37,424		)		(32,872		)	(28,971		)
	Amortization of Prior Service Cost (Credit)	210			238				269				(2,138		)		(2,138		)	(2,138		)
	Amortization of Transition Amount	—			—				—				—				8			10
	Recognition of Actuarial Loss(1)	36,007			52,776				39,615				2,645				20,892			24,057
	Net Amortization and Deferral for Regulatory Purposes	8,151			(10,406		)		(6,900		)		23,263				11,844			6,162
	Net Periodic Benefit Cost	$	39,955		$	37,606			$	29,011			$	10,593			$	21,651		$	24,451
	Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost at September 30
	Discount Rate	4.75		%	3.5		%		4.5		%		4.75		%		3.5		%	4.5		%
	Expected Return on Plan Assets	8		%	8		%		8.25		%		8		%		8		%	8.25		%
	Rate of Compensation Increase	4.75		%	4.75		%		4.75		%		4.75		%		4.75		%	4.75		%
	-1	Distribution Corporation’s New York jurisdiction calculates the amortization of the actuarial loss on a vintage year basis over 10 years, as mandated by the NYPSC. All the other subsidiaries of the Company utilize the corridor approach.
Schedule Of Cumulative Amounts Recognized In AOCI (Loss) And Regulatory Assets And Liabilities	'
		Retirement			Other				Non-Qualified
		Plan			Post-Retirement				Benefit Plans
					Benefits
		(Thousands)
	Amounts Recognized in Accumulated Other Comprehensive Income (Loss), Regulatory Assets and Regulatory Liabilities(1)
	Net Actuarial Loss	$	(226,897	)	$	(32,082	)		$	(23,532	)
	Prior Service (Cost) Credit	(856		)	6,940				—
	Net Amount Recognized	$	(227,753	)	$	(25,142	)		$	(23,532	)
	Changes to Accumulated Other Comprehensive Income (Loss), Regulatory Assets and Regulatory Liabilities Recognized During Fiscal 2014(1)
	Decrease (Increase) in Actuarial Loss, excluding amortization(2)	$	(20,622	)	$	6,387			$	(5,424	)
	Change due to Amortization of Actuarial Loss	36,007			2,645				3,008
	Prior Service (Cost) Credit	210			(2,138		)		—
	Net Change	$	15,595		$	6,894			$	(2,416	)
	Amounts Expected to be Recognized in Net Periodic Benefit Cost in the Next Fiscal Year(1)
	Net Actuarial Loss	$	(36,129	)	$	(4,148	)		$	(2,925	)
	Prior Service (Cost) Credit	(183		)	1,913				—
	Net Amount Expected to be Recognized	$	(36,312	)	$	(2,235	)		$	(2,925	)
	-1	Amounts presented are shown before recognizing deferred taxes.
	-2	Amounts presented include the impact of actuarial gains/losses related to return on assets, as well as the Actuarial (Gain) Loss amounts presented in the Change in Benefit Obligation.
Schedule Of Expected Benefit Payments	'
		Benefit Payments			Subsidy Receipts
	2015	$	25,594		$	(1,955	)
	2016	$	26,909		$	(2,143	)
	2017	$	28,113		$	(2,323	)
	2018	$	29,226		$	(2,511	)
	2019	$	30,173		$	(2,708	)
	2020 through 2024	$	163,470		$	(16,104	)
Schedule Of Health Care Cost Trend Rates	'
		2014			2013				2012
	Rate of Increase for Pre Age 65 Participants	7.1	%	-1	7.28	%	-1		7.46	%	-1
	Rate of Increase for Post Age 65 Participants	6.73	%	-1	6.78	%	-1		6.84	%	-1
	Annual Rate of Increase in the Per Capita Cost of Covered Prescription Drug Benefits	7.47	%	-1	7.78	%	-1		8.08	%	-1
	Annual Rate of Increase in the Per Capita Medicare Part B Reimbursement	6.73	%	-1	6.78	%	-1		6.84	%	-1
	Annual Rate of Increase in the Per Capita Medicare Part D Subsidy	6.79	%	-1	7.03	%	-1		7.13	%	-1
	-1	It was assumed that this rate would gradually decline to 4.5% by 2028.
Other Post-Retirement Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule Of Fair Value Of Plan Assets	'
		Total Fair Value			Level 1				Level 2				Level 3
		Amounts at
		September 30, 2014
	Other Post-Retirement Benefit Assets held in VEBA Trusts
	Collective Trust Funds — Domestic Equities	$	148,219		$	—			$	148,219			$	—
	Collective Trust Funds — International Equities	54,881			—				54,881				—
	Exchange Traded Funds — Fixed Income	236,513			236,513				—				—
	Cash Held in Collective Trust Funds	6,412			—				6,412				—
	Total VEBA Trust Investments	446,025			236,513				209,512				—
	401(h) Investments	54,921			14,105				37,907				2,909
	Total Investments (including 401(h) Investments)	$	500,946		$	250,618			$	247,419			$	2,909
	Miscellaneous Accruals (Including Current and Deferred Taxes, Claims Incurred But Not Reported, Administrative)	(3,345		)
	Total Other Post-Retirement Benefit Assets	$	497,601
		Total Fair Value			Level 1				Level 2				Level 3
		Amounts at
		September 30, 2013
	Other Post-Retirement Benefit Assets held in VEBA Trusts
	Collective Trust Funds — Domestic Equities	$	205,623		$	—			$	205,623			$	—
	Collective Trust Funds — International Equities	87,613			—				87,613				—
	Exchange Traded Funds — Fixed Income	122,558			122,558				—				—
	Real Estate	55			—				—				55
	Cash Held in Collective Trust Funds	11,678			—				11,678				—
	Total VEBA Trust Investments	427,527			122,558				304,914				55
	401(h) Investments	49,453			20,141				26,706				2,606
	Total Investments (including 401(h) Investments)	$	476,980		$	142,699			$	331,620			$	2,661
	Miscellaneous Accruals (Including Current and Deferred Taxes, Claims Incurred But Not Reported, Administrative)	(4,588		)
	Total Other Post-Retirement Benefit Assets	$	472,392
Schedule Of Significant Unobservable Input Changes In Plan Assets	'
		Other Post-Retirement Benefit Level 3 Assets
		(Thousands)
		VEBA			Including				Other
		Trust			401(h)				Post-Retirement
		Investments			Investments				Benefit
		Real							Investments
		Estate
	Balance at September 30, 2012	$	1,305		$	2,680			$	3,985
	Realized Gains/(Losses)	940			(4		)		936
	Unrealized Gains/(Losses)	385			156				541
	Purchases	—			11				11
	Sales	(2,575		)	(237		)		(2,812		)
	Balance at September 30, 2013	55			2,606				2,661
	Realized Gains/(Losses)	(40		)	4				(36		)
	Unrealized Gains/(Losses)	—			239				239
	Purchases	—			65				65
	Sales	(15		)	(5		)		(20		)
	Balance at September 30, 2014	$	—		$	2,909			$	2,909
Retirement Plan [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule Of Fair Value Of Plan Assets	'
		Total Fair Value			Level 1				Level 2				Level 3
		Amounts at
		September 30, 2014
	Retirement Plan Investments
	Domestic Equities(1)	$	268,649		$	171,979			$	96,670			$	—
	International Equities(2)	80,957			1,969				78,988				—
	Global Equities(3)	104,238			—				104,238				—
	Domestic Fixed Income(4)	299,494			63,187				236,307				—
	International Fixed Income(5)	1,240			508				732				—
	Global Fixed Income(6)	93,704			—				93,704				—
	Hedge Fund Investments	45,213			—				—				45,213
	Real Estate	3,792			—				—				3,792
	Cash and Cash Equivalents	33,544			—				33,544				—
	Total Retirement Plan Investments	930,831			237,643				644,183				49,005
	401(h) Investments	(54,921		)	(14,105		)		(37,907		)		(2,909		)
	Total Retirement Plan Investments (excluding 401(h) Investments)	$	875,910		$	223,538			$	606,276			$	46,096
	Miscellaneous Accruals, Interest Receivables, and Non-Interest Cash	(6,119		)
	Total Retirement Plan Assets	$	869,791
		Total Fair Value			Level 1				Level 2				Level 3
		Amounts at
		September 30, 2013
	Retirement Plan Investments
	Domestic Equities(1)	$	402,107		$	271,071			$	131,036			$	—
	International Equities(2)	103,028			2,355				100,673				—
	Global Equities(3)	25,325			—				25,325				—
	Domestic Fixed Income(4)	163,750			71,185				92,565				—
	International Fixed Income(5)	2,762			1,318				1,444				—
	Global Fixed Income(6)	88,084			—				88,084				—
	Hedge Fund Investments	42,027			—				—				42,027
	Real Estate	2,723			—				—				2,723
	Cash and Cash Equivalents	22,694			—				22,694				—
	Total Retirement Plan Investments	852,500			345,929				461,821				44,750
	401(h) Investments	(49,453		)	(20,141		)		(26,706		)		(2,606		)
	Total Retirement Plan Investments (excluding 401(h) Investments)	$	803,047		$	325,788			$	435,115			$	42,144
	Miscellaneous Accruals, Interest Receivables, and Non-Interest Cash	(3,740		)
	Total Retirement Plan Assets	$	799,307
	-1	Domestic Equities include mostly collective trust funds, common stock, and exchange traded funds.
	-2	International Equities include mostly collective trust funds and common stock.
	-3	Global Equities are comprised of a collective trust fund.
	-4	Domestic Fixed Income securities include mostly collective trust funds, corporate/government bonds and mortgages, and exchange traded funds.
	-5	International Fixed Income securities include mostly collective trust funds and exchange traded funds.
	-6	Global Fixed Income securities are comprised of a collective trust fund.
Schedule Of Significant Unobservable Input Changes In Plan Assets	'
			Retirement Plan Level 3 Assets
			(Thousands)
			Hedge			Real				Excluding				Total
			Funds			Estate				401(h)
										Investments
		Balance at September 30, 2012	$	39,956		$	6,170			$	(2,680	)		$	43,446
		Realized Gains/(Losses)	—			(73		)		4				(69		)
		Unrealized Gains/(Losses)	2,071			515				(156		)		2,430
		Purchases	—			188				(11		)		177
		Sales	—			(4,077		)		237				(3,840		)
		Balance at September 30, 2013	42,027			2,723				(2,606		)		42,144
		Realized Gains/(Losses)	—			62				(4		)		58
		Unrealized Gains/(Losses)	3,186			(10		)		(239		)		2,937
		Purchases	—			1,111				(65		)		1,046
		Sales	—			(94		)		5				(89		)
		Balance at September 30, 2014	$	45,213		$	3,792			$	(2,909	)		$	46,096

Business_Segment_Information_T

Business Segment Information (Tables)	12 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Information By Segment	'
		Year Ended September 30, 2014
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Eliminations
		(Thousands)
	Revenue from External Customers(1)	$	804,096	$	200,664	$	673	$	831,156	$	271,993	$	2,108,582	$	3,532		$	967		$	2,113,081
	Intersegment Revenues	$	—	$	83,744	$	69,937	$	18,462	$	1,159	$	173,302	$	—		$	(173,302	)	$	—
	Interest Income	$	1,909	$	284	$	120	$	3,010	$	173	$	5,496	$	106		$	(1,432	)	$	4,170
	Interest Expense	$	42,232	$	26,428	$	1,726	$	27,693	$	31	$	98,110	$	6		$	(3,839	)	$	94,277
	Depreciation, Depletion and Amortization	$	296,210	$	36,642	$	6,116	$	43,594	$	197	$	382,759	$	344		$	678		$	383,781
	Income Tax Expense (Benefit)	$	81,370	$	47,100	$	23,636	$	33,918	$	3,761	$	189,785	$	822		$	(993	)	$	189,614
	Segment Profit: Net Income (Loss)	$	121,569	$	77,559	$	32,709	$	64,059	$	6,631	$	302,527	$	1,160		$	(4,274	)	$	299,413
	Expenditures for Additions to Long-Lived Assets	$	602,705	$	139,821	$	137,799	$	88,810	$	264	$	969,399	$	274		$	234		$	969,907
		At September 30, 2014
		(Thousands)
	Segment Assets	$	3,100,514	$	1,367,181	$	326,662	$	1,862,850	$	76,238	$	6,733,445	$	86,460		$	(80,308	)	$	6,739,597
		Year Ended September 30, 2013
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Elimination
		(Thousands)
	Revenue from External Customers(1)	$	702,937	$	178,184	$	1,324	$	730,319	$	211,990	$	1,824,754	$	3,910		$	887		$	1,829,551
	Intersegment Revenues	$	—	$	89,424	$	33,457	$	16,020	$	1,384	$	140,285	$	—		$	(140,285	)	$	—
	Interest Income	$	1,501	$	193	$	55	$	3,417	$	169	$	5,335	$	115		$	(1,115	)	$	4,335
	Interest Expense	$	39,745	$	26,248	$	2,283	$	29,076	$	36	$	97,388	$	2		$	(3,279	)	$	94,111
	Depreciation, Depletion and Amortization	$	243,431	$	35,156	$	3,945	$	42,729	$	123	$	325,384	$	577		$	799		$	326,760
	Income Tax Expense (Benefit)	$	95,317	$	38,626	$	10,287	$	31,065	$	2,450	$	177,745	$	529		$	(5,516	)	$	172,758
	Segment Profit: Net Income (Loss)	$	115,391	$	63,245	$	13,321	$	65,686	$	4,589	$	262,232	$	894		$	(3,125	)	$	260,001
	Expenditures for Additions to Long-Lived Assets	$	533,129	$	56,144	$	54,792	$	71,970	$	595	$	716,630	$	307		$	160		$	717,097
		At September 30, 2013
		(Thousands)
	Segment Assets	$	2,746,233	$	1,246,027	$	203,323	$	1,870,587	$	67,267	$	6,133,437	$	95,793		$	(10,883	)	$	6,218,347
		Year Ended September 30, 2012
		Exploration		Pipeline		Gathering		Utility		Energy		Total		All			Corporate			Total
		and		and						Marketing		Reportable		Other			and			Consolidated
		Production		Storage								Segments					Intersegment
																	Eliminations
		(Thousands)
	Revenue from External Customers(1)	$	558,180	$	172,312	$	704	$	704,518	$	186,579	$	1,622,293	$	3,603		$	957		$	1,626,853
	Intersegment Revenues	$	—	$	86,963	$	16,771	$	14,604	$	1,425	$	119,763	$	—		$	(119,763	)	$	—
	Interest Income	$	1,493	$	199	$	1	$	2,765	$	188	$	4,646	$	174		$	(1,131	)	$	3,689
	Interest Expense	$	29,243	$	25,603	$	1,444	$	33,181	$	41	$	89,512	$	294		$	(3,566	)	$	86,240
	Depreciation, Depletion and Amortization	$	187,624	$	38,182	$	1,691	$	42,757	$	90	$	270,344	$	400		$	786		$	271,530
	Income Tax Expense (Benefit)	$	79,050	$	37,655	$	4,825	$	29,110	$	1,933	$	152,573	$	(490	)	$	(1,529	)	$	150,554
	Segment Profit: Net Income (Loss)	$	96,498	$	60,527	$	6,855	$	58,590	$	4,169	$	226,639	$	13		$	(6,575	)	$	220,077
	Expenditures for Additions to Long-Lived Assets	$	693,810	$	144,167	$	80,012	$	58,284	$	770	$	977,043	$	5		$	346		$	977,394
		At September 30, 2012
		(Thousands)
	Segment Assets	$	2,367,485	$	1,243,862	$	116,756	$	2,070,413	$	61,968	$	5,860,484	$	93,178		$	(18,520	)	$	5,935,142
	-1	All Revenue from External Customers originated in the United States.
Schedule Of Long-Lived Assets, By Geographical Areas	'
	Geographic Information	At September 30
		2014		2013		2012
		(Thousands)
	Long-Lived Assets:
	United States	$	6,362,265	$	5,769,670	$	5,579,566

Quarterly_Financial_Data_Table

Quarterly Financial Data (Tables)	12 Months Ended
	Sep. 30, 2014
Quarterly Financial Information Disclosure [Abstract]	'
Schedule Of Quarterly Financial Information	'
		Quarter Ended	Operating		Operating		Net  Income			Earnings per
			Revenues		Income		Available for			Common Share
							Common Stock			Basic		Diluted
			(Thousands, except per common share amounts)
		2014
		9/30/14	$	366,623	$	102,004	$	57,431		$	0.68	$	0.68
		6/30/14	$	440,144	$	127,013	$	64,520		$	0.77	$	0.76
		3/31/14	$	756,242	$	180,075	$	95,210	-1	$	1.14	$	1.12
		12/31/13	$	550,072	$	160,581	$	82,252		$	0.98	$	0.97
		2013
		9/30/13	$	338,863	$	96,636	$	47,842	-2	$	0.57	$	0.57
		6/30/13	$	440,008	$	127,004	$	58,495		$	0.7	$	0.69
		3/31/13	$	597,826	$	162,991	$	85,720		$	1.03	$	1.02
		12/31/12	$	452,854	$	131,207	$	67,944		$	0.81	$	0.81
	-1	Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.
	-2	Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

Market_For_Common_Stock_And_Re1

Market For Common Stock And Related Shareholder Matters (Tables)	12 Months Ended
	Sep. 30, 2014
Market For Common Stock And Related Shareholder Matters [Abstract]	'
Schedule Of Price Ranges And Dividends Declared	'
	The quarterly price ranges (based on intra-day prices) and quarterly dividends declared for the fiscal years ended September 30, 2014 and 2013, are shown below:
		Price Range				Dividends
	Quarter Ended	High		Low		Declared
	2014
	9/30/14	$	78.79	$	65.29	$	0.385
	6/30/14	$	78.46	$	68.5	$	0.385
	3/31/14	$	77.05	$	68.12	$	0.375
	12/31/13	$	72.53	$	65.23	$	0.375
	2013
	9/30/13	$	69.27	$	57.52	$	0.375
	6/30/13	$	64.58	$	56.8	$	0.375
	3/31/13	$	61.44	$	48.51	$	0.365
	12/31/12	$	55.66	$	49	$	0.365

Supplementary_Information_For_1

Supplementary Information For Oil And Gas Producing Activities (Tables)	12 Months Ended
	Sep. 30, 2014
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'
Capitalized Costs Relating To Oil And Gas Producing Activities	'
	Capitalized Costs Relating to Oil and Gas Producing Activities
		At September 30
		2014				2013
		(Thousands)
	Proved Properties(1)	$	3,941,143			$	3,393,612
	Unproved Properties	141,719				106,085
		4,082,862				3,499,697
	Less — Accumulated Depreciation, Depletion and Amortization	1,211,610				919,989
		$	2,871,252			$	2,579,708
	-1	Includes asset retirement costs of $75.7 million and $80.6 million at September 30, 2014 and 2013, respectively.
Summary Of Capitalized Costs Of Unproved Properties Excluded From Amortization	'
	Following is a summary of costs excluded from amortization at September 30, 2014:
		Total				Year Costs Incurred
		as of
		September 30,
		2014				2014				2013			2012		Prior
		(Thousands)
	Acquisition Costs	$	61,712			$	7,057			$	905		$	5,585	$	48,165
	Development Costs	42,362				39,339				677			1,405		941
	Exploration Costs	36,882				36,882				—			—		—
	Capitalized Interest	763				763				—			—		—
		$	141,719			$	84,041			$	1,582		$	6,990	$	49,106
Costs Incurred In Oil And Gas Property Acquisition, Exploration And Development Activities	'
	Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities
		Year Ended September 30
		2014				2013				2012
		(Thousands)
	United States
	Property Acquisition Costs:
	Proved	$	18,213			$	7,575			$	13,095
	Unproved	7,884				9,274				13,867
	Exploration Costs(1)	71,850				49,483				84,624
	Development Costs(2)	490,164				460,554				576,397
	Asset Retirement Costs	(4,946		)		37,546				10,344
		$	583,165			$	564,432			$	698,327
	-1	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.4 million and $1.0 million, respectively.
	-2	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.7 million and $2.0 million, respectively.
Results Of Operations For Producing Activities	'
	Results of Operations for Producing Activities
		Year Ended September 30
		2014				2013				2012
		(Thousands, except per Mcfe amounts)
	United States
	Operating Revenues:
	Natural Gas (includes revenues from sales to affiliates of $1 for all years presented and transfers to operations of $2,145, $612 and $0, respectively)	$	515,080			$	371,311			$	181,544
	Oil, Condensate and Other Liquids	298,179				291,762				307,018
	Total Operating Revenues(1)	813,259				663,073				488,562
	Production/Lifting Costs	165,534				119,243				83,361
	Franchise/Ad Valorem Taxes	20,765				17,200				23,620
	Accretion Expense	6,192				3,929				3,084
	Depreciation, Depletion and Amortization ($1.82, $1.98 and $2.19 per Mcfe of production)	291,651				238,467				182,759
	Income Tax Expense	140,484				120,431				81,904
	Results of Operations for Producing Activities (excluding corporate overheads and interest charges)	$	188,633			$	163,803			$	113,834
	-1	Exclusive of hedging gains and losses. See further discussion in Note G — Financial Instruments.
Proved Developed And Undeveloped Oil And Gas Reserve Quantities	'
		Gas MMcf
		U. S.
		Appalachian			West			Total
		Region			Coast			Company
					Region
	Proved Developed and Undeveloped Reserves:
	September 30, 2011	606,606			68,316			674,922
	Extensions and Discoveries	435,460		-1	638			436,098
	Revisions of Previous Estimates	(53,992	)		(2,463	)		(56,455	)
	Production	(62,663	)	-2	(3,468	)		(66,131	)
	September 30, 2012	925,411			63,023			988,434
	Extensions and Discoveries	360,922		-1	702			361,624
	Revisions of Previous Estimates	53,038			112			53,150
	Production	(100,633	)	-2	(3,060	)		(103,693	)
	September 30, 2013	1,238,738			60,777			1,299,515
	Extensions and Discoveries	446,821		-1	—			446,821
	Revisions of Previous Estimates	43,690			1,358			45,048
	Production	(139,097	)	-2	(3,210	)		(142,307	)
	Purchases of Minerals in Place	33,986			—			33,986
	Sale of Minerals in Place	(76	)		(103	)		(179	)
	September 30, 2014	1,624,062			58,822			1,682,884
	Proved Developed Reserves:
	September 30, 2011	350,458			63,965			414,423
	September 30, 2012	544,560			59,923			604,483
	September 30, 2013	807,055			59,862			866,917
	September 30, 2014	1,119,901			57,907			1,177,808
	Proved Undeveloped Reserves:
	September 30, 2011	256,148			4,351			260,499
	September 30, 2012	380,851			3,100			383,951
	September 30, 2013	431,683			915			432,598
	September 30, 2014	504,161			915			505,076
	-1	Extensions and discoveries include 435 Bcf (during 2012), 355 Bcf (during 2013) and 442 Bcf (during 2014), of Marcellus Shale gas in the Appalachian Region.
	-2	Production includes 55,812 MMcf (during 2012), 93,999 MMcf (during 2013) and 131,590 MMcf (during 2014), from Marcellus Shale fields (which exceed 15% of total reserves).
		Oil Mbbl
		U. S.
		Appalachian			West			Total
		Region			Coast			Company
					Region
	Proved Developed and Undeveloped Reserves:
	September 30, 2011	279			43,066			43,345
	Extensions and Discoveries	28			1,229			1,257
	Revisions of Previous Estimates	35			1,095			1,130
	Production	(36	)		(2,834	)		(2,870	)
	September 30, 2012	306			42,556			42,862
	Extensions and Discoveries	—			2,443			2,443
	Revisions of Previous Estimates	5			(881	)		(876	)
	Production	(28	)		(2,803	)		(2,831	)
	September 30, 2013	283			41,315			41,598
	Extensions and Discoveries	18			1,521			1,539
	Revisions of Previous Estimates	(17	)		(1,677	)		(1,694	)
	Production	(31	)		(3,005	)		(3,036	)
	Purchases of Minerals in Place	—			83			83
	Sales of Minerals in Place	—			(13	)		(13	)
	September 30, 2014	253			38,224			38,477
	Proved Developed Reserves:
	September 30, 2011	274			37,306			37,580
	September 30, 2012	306			38,138			38,444
	September 30, 2013	283			38,082			38,365
	September 30, 2014	253			37,002			37,255
	Proved Undeveloped Reserves:
	September 30, 2011	5			5,760			5,765
	September 30, 2012	—			4,418			4,418
	September 30, 2013	—			3,233			3,233
September 30, 2014	—			1,222			1,222
Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves	'
		Year Ended September 30
		2014				2013				2012
		(Thousands)
	United States
	Future Cash Inflows	$	10,001,545			$	8,943,942			$	7,373,129
	Less:
	Future Production Costs	2,795,657				2,334,393				1,919,530
	Future Development Costs	790,033				749,876				619,573
	Future Income Tax Expense at Applicable Statutory Rate	2,434,370				2,113,101				1,812,055
	Future Net Cash Flows	3,981,485				3,746,572				3,021,971
	Less:
	10% Annual Discount for Estimated Timing of Cash Flows	1,914,607				1,780,206				1,552,180
	Standardized Measure of Discounted Future Net Cash Flows	$	2,066,878			$	1,966,366			$	1,469,791
Principal Sources Of Change In The Standardized Measure Of Discounted Future Net Cash Flows	'
	The principal sources of change in the standardized measure of discounted future net cash flows were as follows:
		Year Ended September 30
		2014				2013				2012
		(Thousands)
	United States
	Standardized Measure of Discounted Future
	Net Cash Flows at Beginning of Year	$	1,966,366			$	1,469,791			$	1,524,157
	Sales, Net of Production Costs	(626,960		)		(526,630		)		(381,581		)
	Net Changes in Prices, Net of Production Costs	(38,723		)		339,655				(385,019		)
	Extensions and Discoveries	381,008				390,255				224,474
	Changes in Estimated Future Development Costs	68,731				6,117				29,627
	Purchases of Minerals in Place	34,705				—				—
	Sales of Minerals in Place	(691		)		—				—
	Previously Estimated Development Costs Incurred	179,502				148,535				252,967
	Net Change in Income Taxes at Applicable Statutory Rate	(231,807		)		(130,574		)		(19,280		)
	Revisions of Previous Quantity Estimates	55,184				34,864				103,472
	Accretion of Discount and Other	279,563				234,353				120,974
	Standardized Measure of Discounted Future Net Cash Flows at End of Year	$	2,066,878			$	1,966,366			$	1,469,791

Summary_Of_Significant_Account3

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Full cost ceiling test discount factor	10.00%	'	'
Increase (decrease) estimated future net cash flows	($33,600,000)	$71,600,000	$128,400,000
Amount full cost ceiling exceeds book value of oil and gas properties	148,400,000	'	'
Goodwill	5,476,000	5,476,000	'
Prior service credit	200,000	300,000	'
Gas stored underground - current	39,422,000	51,484,000	'
Customer Advances	19,005,000	21,959,000	'
Customer Security Deposits	15,761,000	16,183,000	'
Antidilutive securities	1,007	181,418	844,872
Accumulated Losses [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Accumulated losses	56,200,000	56,600,000	'
Unamortized Debt Expense [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Regulated Reacquisition of Debt Cost Weighted Average Amortization Period	'5 years	'	'
Amount Exceeds LIFO Basis [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Gas stored underground - current	33,200,000	'	'
LIFO Method [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Gas stored underground - current	$25,300,000	'	'

Summary_Of_Significant_Account4

Summary Of Significant Accounting Policies (Schedule Of Depreciable Plant By Segment) (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Depreciable plant	$7,791,390	$7,006,331
Utility [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	1,833,104	1,778,140
Pipeline And Storage [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	1,609,593	1,547,192
Exploration And Production [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	3,996,834	3,437,767
Energy Marketing [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	3,366	3,460
Gathering [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	239,507	130,082
All Other And Corporate [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Depreciable plant	$108,986	$109,690

Summary_Of_Significant_Account5

Summary Of Significant Accounting Policies (Average Depreciation Depletion And Amortization Rates) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Exploration And Production [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Depreciation depletion and amortization rate per Mcfe	$1.85	[1]	$2.02	[1]	$2.25	[1]
Utility [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Average depreciation, depletion and amortization rates	2.60%		2.60%		2.60%
Pipeline And Storage [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Average depreciation, depletion and amortization rates	2.40%		2.50%		2.90%
Energy Marketing [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Average depreciation, depletion and amortization rates	5.80%		3.90%		3.60%
Gathering [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Average depreciation, depletion and amortization rates	3.30%		3.70%		3.30%
All Other And Corporate [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Average depreciation, depletion and amortization rates	0.90%		1.30%		1.10%
Oil And Gas Producing Properties [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Depreciation depletion and amortization rate per Mcfe	$1.82		$1.98		$2.19
[1]	Amounts include depletion of oil and gas producing properties as well as depreciation of fixed assets. As disclosed in Note M — Supplementary Information for Oil and Gas Producing Properties, depletion of oil and gas producing properties amounted to $1.82, $1.98 and $2.19 per Mcfe of production in 2014, 2013 and 2012, respectively.

Summary_Of_Significant_Account6

Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Accumulated Other Comprehensive Income [Roll Forward]	'
Beginning balance	($19,234)
Other Comprehensive Gains and Losses Before Reclassifications	1,710
Amounts Reclassified From Other Comprehensive Loss	13,545
Ending balance	-3,979
Gains and Losses on Derivative Financial Instruments [Member]	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Beginning balance	30,722
Other Comprehensive Gains and Losses Before Reclassifications	4,805
Amounts Reclassified From Other Comprehensive Loss	8,132
Ending balance	43,659
Gains And Losses On Securities Available For Sale [Member]	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Beginning balance	6,337
Other Comprehensive Gains and Losses Before Reclassifications	2,465
Amounts Reclassified From Other Comprehensive Loss	-420
Ending balance	8,382
Funded Status of the Pension and Other Post-Retirement Benefit Plans [Member]	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Beginning balance	-56,293
Other Comprehensive Gains and Losses Before Reclassifications	-5,560
Amounts Reclassified From Other Comprehensive Loss	5,833
Ending balance	($56,020)

Summary_Of_Significant_Account7

Summary Of Significant Accounting Policies Summary Of Significant Accounting Policies (Reclassification Out of Accumulated Other Comprehensive Loss) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Operating Revenues

$366,623

$440,144

$756,242

$550,072

$338,863

$440,008

$597,826

$452,854

$2,113,081

$1,829,551

$1,626,853

Purchased Gas

'

'

'

'

'

'

'

'

-605,838

-460,432

-415,589

Other Income

'

'

'

'

'

'

'

'

9,461

4,697

5,133

Income Before Income Taxes

'

'

'

'

'

'

'

'

489,027

432,759

370,631

Income Tax Expense

'

'

'

'

'

'

'

'

-189,614

-172,758

-150,554

Net Income Available for Common Stock

57,431

64,520

95,210

[1]

82,252

47,842

[2]

58,495

85,720

67,944

299,413

260,001

220,077

Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Loss [Member]

'

'

'

'

'

'

'

'

'

'

'

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Income Before Income Taxes

'

'

'

'

'

'

'

'

-26,188

'

'

Income Tax Expense

'

'

'

'

'

'

'

'

12,643

'

'

Net Income Available for Common Stock

'

'

'

'

'

'

'

'

-13,545

'

'

Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Loss [Member] | Gains and Losses on Securities Available for Sale [Member]

'

'

'

'

'

'

'

'

'

'

'

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Other Income

'

'

'

'

'

'

'

'

662

'

'

Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Loss [Member] | Amortization of Prior Year Funded Status of Pension and Other Post-Retirement Benefit Plans [Member] | Prior Service Credit [Member]

'

'

'

'

'

'

'

'

'

'

'

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net periodic benefit cost

'

'

'

'

'

'

'

'

131

[3]

'

'

Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Loss [Member] | Amortization of Prior Year Funded Status of Pension and Other Post-Retirement Benefit Plans [Member] | Net Actuarial Loss [Member]

'

'

'

'

'

'

'

'

'

'

'

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net periodic benefit cost

'

'

'

'

'

'

'

'

-9,334

[3]

'

'

Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Loss [Member] | Commodity Contract [Member] | Gains and Losses on Derivative Financial Instruments [Member]

'

'

'

'

'

'

'

'

'

'

'

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Operating Revenues

'

'

'

'

'

'

'

'

-14,880

'

'

Purchased Gas

'

'

'

'

'

'

'

'

($2,767)

'

'

[1]

Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.

[2]

Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

[3]

These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note H — Retirement Plan and Other Post-Retirement Benefits for additional details.

Summary_Of_Significant_Account8

Summary Of Significant Accounting Policies (Components Of Other Current Assets) (Details) (USD $)	Sep. 30, 2014		Sep. 30, 2013
In Thousands, unless otherwise specified
Summary Of Significant Accounting Policies [Line Items]	'		'
Prepayments	$10,079		$10,605
Prepaid Property and Other Taxes	13,743		13,079
Fair Values of Firm Commitments	0		1,829
Regulatory Assets	22,719	[1]	26,995	[1]
Other Current Assets	54,752		56,905
Federal [Member]	'		'
Summary Of Significant Accounting Policies [Line Items]	'		'
Income Taxes Receivable	8,211		1,122
State [Member]	'		'
Summary Of Significant Accounting Policies [Line Items]	'		'
Income Taxes Receivable	$0		$3,275
[1]	The Company recovers the cost of its regulatory assets but generally does not earn a return on them. There are a few exceptions to this rule. For example, the Company does earn a return on Unrecovered Purchased Gas Costs and, in the New York jurisdiction of its Utility segment, earns a return, within certain parameters, on the excess of cumulative funding to the pension plan over the cumulative amount collected in rates.

Summary_Of_Significant_Account9

Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Summary Of Significant Accounting Policies [Line Items]	'	'
Regulatory Liability	$51,817	$32,841
Other Accruals and Current Liabilities	136,672	83,946
Accrued Capital Expenditures [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Other	80,348	41,100
Regulatory Liabilities [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Regulatory Liability	18,072	20,013
Other Accruals [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Other	32,454	22,833
State [Member]	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'
Income Taxes Payable	$5,798	$0

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'
Balance at Beginning of Year	$119,511	$119,246	$75,731
Liabilities Incurred and Revisions of Estimates	-2,496	-4,796	41,653
Liabilities Settled	-6,955	-1,744	-2,997
Accretion Expense	7,653	6,805	4,859
Balance at End of Year	$117,713	$119,511	$119,246

Regulatory_Matters_Narrative_D

Regulatory Matters (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Regulatory Matters [Line Items]	'	'
Authorized Increase In Distribution Corporation's Pipeline Replacement Spending	$8.20	'
Allowed Rate Of Return On Equity	9.10%	'
Rate proceeding refund provision pre tax	'	$7.50
Maximum [Member]	'	'
Regulatory Matters [Line Items]	'	'
Allowed Rate Of Return On Equity Range	10.50%	'
Minimum [Member]	'	'
Regulatory Matters [Line Items]	'	'
Allowed Rate Of Return On Equity Range	9.50%	'
Shareholder Allocation [Member] | Nine Point Five Percent To Ten Point Five Percent Rate Of Return On Equity [Member]	'	'
Regulatory Matters [Line Items]	'	'
Earnings Sharing Mechanism Allocation Of Earnings	50.00%	'
Shareholder Allocation [Member] | Above10.5 Percent Rate Of Return On Equity [Member]	'	'
Regulatory Matters [Line Items]	'	'
Earnings Sharing Mechanism Allocation Of Earnings	20.00%	'
Deferred For Benefit Of Customers [Member] | Nine Point Five Percent To Ten Point Five Percent Rate Of Return On Equity [Member]	'	'
Regulatory Matters [Line Items]	'	'
Earnings Sharing Mechanism Allocation Of Earnings	50.00%	'
Deferred For Benefit Of Customers [Member] | Above10.5 Percent Rate Of Return On Equity [Member]	'	'
Regulatory Matters [Line Items]	'	'
Earnings Sharing Mechanism Allocation Of Earnings	80.00%	'

Regulatory_Matters_Schedule_Of

Regulatory Matters (Schedule Of Regulatory Assets And Liabilities) (Details) (USD $)	Sep. 30, 2014		Sep. 30, 2013
In Thousands, unless otherwise specified
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	$413,387	[1]	$446,194	[1]
Less: Amounts Included in Other Current Assets	-22,719	[1]	-26,995	[1]
Total Long-Term Regulatory Assets	224,436		252,568
Total Regulatory Liabilities	397,904		337,667
Less: Amounts Included in Current and Accrued Liabilities	-51,817		-32,841
Total Long-Term Regulatory Liabilities	81,152		61,549
Cost Of Removal Regulatory Liability [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	173,199		157,622
Taxes Refundable To Customers [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	91,736		85,655
Post-Retirement Benefit Costs [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	53,650		37,923
Amounts Payable To Customers [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	33,745		12,828
Off-System Sales And Capacity Release Credits [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	12,805	[2]	10,228	[2]
Other Accruals and Current Liabilities [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Less: Amounts Included in Current and Accrued Liabilities	-5,267		-9,785
Other Regulatory Liabilities [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Liabilities	32,769	[3]	33,411	[3]
Total Long-Term Regulatory Liabilities	27,502		23,626
Non-Current Regulatory Liabilities [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Long-Term Regulatory Liabilities	346,087		304,826
Pension Costs Asset [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	164,804	[1],[4]	187,181	[1],[4]
Post-Retirement Benefit Costs [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	17,128	[1],[4]	29,838	[1],[4]
Recoverable Future Taxes [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	163,485	[1]	163,355	[1]
Environmental Site Remediation Costs [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	25,645	[1],[4]	18,104	[1],[4]
NYPSC Assessment [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	12,730	[1],[5]	13,169	[1],[5]
Asset Retirement Obligations [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	12,006	[1],[4]	11,837	[1],[4]
Unamortized Debt Expense [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	2,747	[1]	3,276	[1]
Other Regulatory Assets [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Regulatory Assets	14,842	[1],[6]	19,434	[1],[6]
Total Long-Term Regulatory Assets	4,853		5,608
Other Current Assets [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Less: Amounts Included in Other Current Assets	-9,989		-13,826
Long-Term Regulatory Assets [Member]	'		'
Regulatory Assets And Liabilities [Line Items]	'		'
Total Long-Term Regulatory Assets	$390,668	[1]	$419,199	[1]
[1]	The Company recovers the cost of its regulatory assets but generally does not earn a return on them. There are a few exceptions to this rule. For example, the Company does earn a return on Unrecovered Purchased Gas Costs and, in the New York jurisdiction of its Utility segment, earns a return, within certain parameters, on the excess of cumulative funding to the pension plan over the cumulative amount collected in rates.
[2]	Amounts are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be passed back to ratepayers in the next 12 months.
[3]	$5,267 and $9,785 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $27,502 and $23,626 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.
[4]	Included in Other Regulatory Assets on the Consolidated Balance Sheets.
[5]	Amounts are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and September 30, 2013 since such amounts are expected to be recovered from ratepayers in the next 12 months.
[6]	$9,989 and $13,826 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $4,853 and $5,608 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2014 and 2013, respectively.

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Taxes [Line Items]	'	'	'
Tax benefit recorded from exercise of stock options	$4,600,000	$700,000	$1,000,000
Tax benefit not realized due to tax loss carryforwards	34,200,000	34,200,000	'
Taxes Refundable to Customers	91,736,000	85,655,000	'
Recoverable Future Taxes	163,485,000	163,355,000	'
Tax Credit Carryforwards	36,000,000	'	'
Federal net operating loss, certain annual limitations	10,000,000	'	'
Federal net operating loss, excess tax deductions related to stock based compensation	87,000,000	'	'
Tax benefit from change in enacted rate	-26,272,000	-37,569,000	-32,974,000
Deferred Income Taxes [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Taxes Refundable to Customers	91,736,000	85,655,000	'
Recoverable Future Taxes	163,485,000	163,355,000	'
Regulatory liabilities	52,600,000	52,600,000	'
Regulatory assets	85,300,000	82,500,000	'
Pennsylvania [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Net operating loss	297,000,000	'	'
California [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Net operating loss	183,000,000	'	'
New York [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Net operating loss	103,000,000	'	'
Federal [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Net operating loss	367,000,000	'	'
State Tax Law Change [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Tax benefit from change in enacted rate	$2,800,000	'	'
New York [Member] | State and Local Jurisdiction [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Corporate Tax Rate	7.10%	'	'
Effective January 1, 2016 [Member] | New York [Member] | State and Local Jurisdiction [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Corporate Tax Rate	6.50%	'	'

Income_Taxes_Components_Of_Fed

Income Taxes (Components Of Federal And State Income Taxes Included In The Consolidated Statements Of Income) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Current Income Taxes [Abstract]	'	'	'
Federal	$34,579	($632)	($8)
State	12,620	5,503	6,412
Deferred Income Taxes [Abstract]	'	'	'
Federal	116,143	130,318	111,176
State	26,272	37,569	32,974
Income Tax Expense	189,614	172,758	150,554
Deferred Investment Tax Credit	-434	-426	-581
Total Income Taxes	189,180	172,332	149,973
Presented as Follows [Abstract]	'	'	'
Other Income	-434	-426	-581
Income Tax Expense	$189,614	$172,758	$150,554

Income_Taxes_Schedule_Of_Incom

Income Taxes (Schedule Of Income Tax Reconciliation By Applying Federal Income Tax Rate) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'
U.S. Income Before Income Taxes	$488,593	$432,333	$370,050
Income Tax Expense, Computed at U.S. Federal Statutory Rate of 35%	171,008	151,317	129,518
Increase (Reduction) in Taxes Resulting from State Income Taxes	25,280	27,997	25,601
Increase (Reduction) in Taxes Resulting From Miscellaneous	-7,108	-6,982	-5,146
Total Income Taxes	$189,180	$172,332	$149,973
Federal Statutory Rate	35.00%	35.00%	35.00%

Income_Taxes_Significant_Compo

Income Taxes (Significant Components Of Deferred Tax Liabilities And Assets) (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Property, Plant and Equipment	$1,614,515	$1,504,187
Pension and Other Post-Retirement Benefit Costs	113,248	124,021
Other	87,935	75,419
Total Deferred Tax Liabilities	1,815,698	1,703,627
Pension and Other Post-Retirement Benefit Costs	-124,452	-130,256
Tax Loss Carryforwards	-171,423	-215,262
Other	-103,863	-90,461
Total Deferred Tax Assets	-399,738	-435,979
Total Net Deferred Income Taxes	1,415,960	1,267,648
Deferred Tax Liability/(Asset) - Current	-40,323	-79,359
Deferred Tax Liability - Non-Current	$1,456,283	$1,347,007

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of The Change In Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'
Balance at Beginning of Year	$2,001	$11,170	$7,766
Additions for Tax Positions Related to Current Year	0	700	1,600
Additions for Tax Positions of Prior Years	2,447	164	2,751
Reductions for Tax Positions of Prior Years	-1,301	-10,033	-947
Balance at End of Year	$3,147	$2,001	$11,170

Capitalization_And_ShortTerm_B2

Capitalization And Short-Term Borrowings (Narrative) (Details) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2014

Sep. 30, 2014

Mar. 31, 2013

Feb. 15, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Stock Options And SARs [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Right [Member]

Stock Appreciation Right [Member]

Stock Appreciation Right [Member]

Restricted Share Awards [Member]

Restricted Share Awards [Member]

Restricted Share Awards [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Performance Based Restricted Stock Units (RSUs) [Member]

Performance Based Restricted Stock Units (RSUs) [Member]

Performance Based Restricted Stock Units (RSUs) [Member]

Performance Shares [Member]

Performance Shares [Member]

Performance Shares [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock [Member]

5.25% Notes Due March 2013 [Member]

3.75% Notes Due In March 1, 2023 [Member]

Indenture From 1974 [Member]

Commercial Paper [Member]

2015 [Member]

2015 [Member]

2016 [Member]

2016 [Member]

2016 [Member]

2017 [Member]

2017 [Member]

2018 [Member]

2018 [Member]

2019 [Member]

2021 [Member]

Board Of Directors [Member]

Restricted Share Awards [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Restricted Share Awards [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Performance Based Restricted Stock Units (RSUs) [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Performance Shares [Member]

Restricted Share Awards [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Non-Performance Based Restricted Stock Units (RSUs) [Member]

Restricted Share Awards [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issue shares of common stock for the Direct Stock Purchase and Dividend Reinvestment Plan

93,731

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued for 401(k) plans

69,729

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock shares issued due to stock option and SARs exercises

-321,500

'

'

433,602

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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Common stock issued

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

12,432

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,412

Shares tendered

126,321

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'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

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'

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'

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'

'

'

'

'

'

'

'

'

'

'

Number of Shares Forfeited

'

'

'

'

'

'

'

0

'

'

'

'

'

3,334

'

'

8,700

'

'

21,728

'

'

17,624

'

'

'

3,334

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of voting power

10.00%

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of assets or earning power that are sold or transferred

50.00%

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

Equity redemption price per share

$0.01

'

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'

'

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'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Voting power percentage to redeem rights

75.00%

'

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'

'

'

'

'

'

'

'

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'

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'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rights expiration date

31-Jul-18

'

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'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-Based Payment Expense

$10,500,000

$11,500,000

$7,200,000

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tax benefit related to stock-based compensation expense

4,300,000

4,600,000

2,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized stock-based compensation costs

100,000

100,000

0

'

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'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tax benefit realized from exercise of stock-based compensation

3,100,000

3,600,000

14,200,000

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tax benefit recorded from exercise of stock-based compensation

4,600,000

700,000

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options, exercises in period, total intrinsic value

'

'

'

'

13,700,000

11,600,000

13,500,000

'

'

'

'

'

'

'

'

'

'

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'

'

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'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Stock Options Exercised

'

'

'

'

7,400,000

2,600,000

7,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

Number of Shares Granted

'

'

'

'

'

'

'

0

412,970

166,000

'

'

'

0

0

41,525

82,151

44,200

68,450

0

255,604

0

116,090

0

0

'

'

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'

'

Weighted Average Fair Value per Award Granted

'

'

'

'

'

'

'

'

$10.66

$11.20

'

'

'

$0

'

$55.09

$65.24

$51.11

$47.10

$0

$49.51

'

$67.16

'

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'

'

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'

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'

'

'

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'

'

'

'

'

Total intrinsic value of SAR's exercised

'

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'

'

'

8,400,000

800,000

100,000

'

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'

'

'

'

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'

'

'

'

'

'

'

'

'

'

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'

'

'

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'

'

Number of Awards Vested

'

'

'

'

'

'

'

'

'

'

323,188

287,168

435,169

34,601

'

'

12,432

'

'

0

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity instruments other than options, vested in period, total fair value

'

'

'

'

'

'

'

3,800,000

3,600,000

3,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation expense

'

'

'

'

'

'

'

500,000

'

'

'

'

'

1,300,000

'

'

5,400,000

'

'

3,100,000

'

'

4,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation expense recognized weighted average period

'

'

'

'

'

'

'

'8 months 0 days

'

'

'

'

'

'2 years 8 months 6 days

'

'

'1 year 8 months 15 days

'

'

'1 year 0 months

'

'

'1 year 6 months 0 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Non-vested stock-based compensation lapse

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

29,518

49,340

5,000

61,534

233,876

59,893

98,466

35,000

22,967

10,785

20,000

'

Carrying Amount

1,649,000,000

1,649,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

99,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt, face value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of Long-Term Debt issued under 1974 Indenture

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt, interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.25%

3.75%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing in 2015

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing in 2016

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing in 2017

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing in 2018

300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing in 2019

250,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amounts of long-term debt maturing after 2019

1,099,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commercial paper available

300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity

750,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commercial paper, outstanding

85,600,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.31%

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Expiration Date

6-Jan-17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Short-term notes payable outstanding

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Committed credit facility debt to capitalization ratio

0.65

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt to capitalization ratio

0.42

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional borrowing

2,740,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum debt increase under existing indenture covenants

1,920,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregated indebtedness

40,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds from issuance of long-term debt

0

495,415,000

496,085,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

495,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current portion of long-term debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

250,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, shares authorized

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock par value

$1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Committed credit facility, outstanding amount

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalization_And_ShortTerm_B3

Capitalization And Short-Term Borrowings (Summary Of Changes In Common Stock Equity) (Details) (USD $)

3 Months Ended

12 Months Ended

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Schedule of Capitalization [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Beginning balance (shares)

'

'

'

83,661,969

'

'

'

'

83,661,969

'

'

Beginning balance

'

'

'

$687,684,000

'

'

'

'

$687,684,000

'

'

Balance at Beginning of Year

'

'

'

1,442,617,000

'

'

'

1,306,284,000

1,442,617,000

1,306,284,000

1,206,022,000

Beginning balance

'

'

'

-19,234,000

'

'

'

'

-19,234,000

'

'

Net Income Available for Common Stock

57,431,000

64,520,000

95,210,000

[1]

82,252,000

47,842,000

[2]

58,495,000

85,720,000

67,944,000

299,413,000

260,001,000

220,077,000

Dividends Declared on Common Stock

'

'

'

'

'

'

'

'

-127,669,000

-123,668,000

-119,815,000

Other Comprehensive Income (Loss), Net of Tax

'

'

'

'

'

'

'

'

15,255,000

79,786,000

-51,321,000

Share-Based Payment Expense

'

'

'

'

'

'

'

'

10,500,000

11,500,000

7,200,000

Ending balance (Shares)

84,157,220

'

'

'

83,661,969

'

'

'

84,157,220

83,661,969

'

Ending balance

716,144,000

'

'

'

687,684,000

'

'

'

716,144,000

687,684,000

'

Balance at End of Year

1,614,361,000

'

'

'

1,442,617,000

'

'

'

1,614,361,000

1,442,617,000

1,306,284,000

Ending balance

-3,979,000

'

'

'

-19,234,000

'

'

'

-3,979,000

-19,234,000

'

Tax benefits related to stock-based compensation

'

'

'

'

'

'

'

'

4,641,000

675,000

985,000

Dividend per share

'

'

'

'

'

'

'

'

$1.52

$1.48

$1.44

Accumulated earnings free from limitations

1,500,000,000

'

'

'

'

'

'

'

1,500,000,000

'

'

Common Stock [Member]

'

'

'

'

'

'

'

'

'

'

'

Schedule of Capitalization [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Beginning balance (shares)

'

'

'

83,662,000

'

'

'

83,330,000

83,662,000

83,330,000

82,813,000

Beginning balance (value)

'

'

'

83,662,000

'

'

'

83,330,000

83,662,000

83,330,000

82,813,000

Common Stock Issued Under Stock and Benefit Plans (Shares)

'

'

'

'

'

'

'

'

495,000

[3]

332,000

[3]

517,000

[3]

Common Stock Issued Under Stock and Benefit Plans (Value)

'

'

'

'

'

'

'

'

495,000

[3]

332,000

[3]

517,000

[3]

Ending balance (Shares)

84,157,000

'

'

'

83,662,000

'

'

'

84,157,000

83,662,000

83,330,000

Ending balance (Value)

84,157,000

'

'

'

83,662,000

'

'

'

84,157,000

83,662,000

83,330,000

Paid In Capital [Member]

'

'

'

'

'

'

'

'

'

'

'

Schedule of Capitalization [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Beginning balance

'

'

'

687,684,000

'

'

'

669,501,000

687,684,000

669,501,000

650,749,000

Share-Based Payment Expense

'

'

'

'

'

'

'

'

10,654,000

[4]

11,537,000

[4]

7,156,000

[4]

Common Stock Issued Under Stock and Benefit Plans (Value)

'

'

'

'

'

'

'

'

17,806,000

[3]

6,646,000

[3]

11,596,000

[3]

Ending balance

716,144,000

'

'

'

687,684,000

'

'

'

716,144,000

687,684,000

669,501,000

Earnings Reinvested In The Business [Member]

'

'

'

'

'

'

'

'

'

'

'

Schedule of Capitalization [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Balance at Beginning of Year

'

'

'

1,442,617,000

'

'

'

1,306,284,000

1,442,617,000

1,306,284,000

1,206,022,000

Net Income Available for Common Stock

'

'

'

'

'

'

'

'

299,413,000

260,001,000

220,077,000

Dividends Declared on Common Stock

'

'

'

'

'

'

'

'

-127,669,000

-123,668,000

-119,815,000

Balance at End of Year

1,614,361,000

[5]

'

'

'

1,442,617,000

'

'

'

1,614,361,000

[5]

1,442,617,000

1,306,284,000

Accumulated Other Comprehensive Income (Loss) [Member]

'

'

'

'

'

'

'

'

'

'

'

Schedule of Capitalization [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Beginning balance

'

'

'

-19,234,000

'

'

'

-99,020,000

-19,234,000

-99,020,000

-47,699,000

Other Comprehensive Income (Loss), Net of Tax

'

'

'

'

'

'

'

'

15,255,000

79,786,000

-51,321,000

Ending balance

($3,979,000)

'

'

'

($19,234,000)

'

'

'

($3,979,000)

($19,234,000)

($99,020,000)

[1]

Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.

[2]

Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

[3]

Paid in Capital includes tax benefits of $4.6 million, $0.7 million and $1.0 million for September 30, 2014, 2013 and 2012, respectively, related to stock-based compensation.

[4]

Paid in Capital includes compensation costs associated with stock option, SARs, performance share and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.

[5]

The availability of consolidated earnings reinvested in the business for dividends payable in cash is limited under terms of the indentures covering long-term debt. At September 30, 2014, $1.5 billion of accumulated earnings was free of such limitations.

Capitalization_And_ShortTerm_B4

Capitalization And Short-Term Borrowings (Schedule Of Share-Based Compensation For Stock Options And Share Awards) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2012
Schedule of Capitalization [Line Items]	'		'	'
Number of Shares Outstanding, Beginning of Year	803,500		'	'
Number of Shares Granted	0		'	'
Number of Shares Exercised	-321,500		'	'
Number of Shares Forfeited	0		'	'
Number of Shares Outstanding, End of Year	482,000		'	'
Number of Option shares exercisable	482,000		'	'
Number of Shares Subject to Option, Option shares available for future grant	712,232	[1]	'	'
Weighted Average Exercise Price, Outstanding Beginning of Year	$34.71		'	'
Weighted Average Exercise Price, Granted	$0		'	'
Weighted Average Exercise Price, Exercised	$31.71		'	'
Weighted Average Exercise Price, Forfeited	$0		'	'
Weighted Average Exercise Price, Outstanding End of Year	$36.71		'	'
Weighted Average Exercise Price, Option shares exercisable	$36.71		'	'
Weighted Average Remaining Contractual Life, Outstanding	'1 year 9 months 20 days		'	'
Weighted Average Remaining Contractual Life, Option shares exercisable	'1 year 9 months 20 days		'	'
Aggregate Intrinsic Value Outstanding	$16,039		'	'
Aggregate Intrinsic Value, Option Shares exercisable	16,039		'	'
Performance Shares [Member]	'		'	'
Schedule of Capitalization [Line Items]	'		'	'
Number of Shares Outstanding, Beginning of Year	0		'	'
Number of Shares Granted	116,090		0	0
Number of Awards Vested	0		'	'
Number of Shares Forfeited	-17,624		'	'
Number of Shares Outstanding, End of Year	98,466		0	'
Weighted Average Fair Value per Award, Beginning of Year	$0		'	'
Weighted Average Fair Value per Award Granted	$67.16		'	'
Weighted Average Fair Value per Award Vested	$0		'	'
Weighted Average Fair Value per Award Forfeited	$67.16		'	'
Weighted Average Fair Value per Award, End of Year	$67.16		$0	'
Stock Appreciation Rights (SARs) [Member]	'		'	'
Schedule of Capitalization [Line Items]	'		'	'
Number of Shares Outstanding, Beginning of Year	2,002,704		'	'
Number of Shares Granted	0		412,970	166,000
Number of Shares Exercised	-209,222		'	'
Number of Shares Forfeited	0		'	'
Number of Shares Cancelled	0		'	'
Number of Shares Outstanding, End of Year	1,793,482		2,002,704	'
Number of SARs exercisable	1,434,023		'	'
Weighted Average Exercise Price, Outstanding Beginning of Year	$48.11		$46.73	'
Weighted Average Exercise Price, Granted	$0		'	'
Weighted Average Exercise Price, Exercised	$34.90		'	'
Weighted Average Exercise Price, Forfeited	$0		'	'
Weighted Average Exercise Price, Cancelled	$0		'	'
Weighted Average Exercise Price, Outstanding End of Year	$48.11		$46.73	'
Weighted Average Exercise Price, SARs exercisable	$46.65		'	'
Weighted Average Remaining Contractual Life, Outstanding	'5 years 11 months 4 days		'	'
Weighted Average Remaining Contractual Life, SARs exercisable	'5 years 5 months 13 days		'	'
Aggregate Intrinsic Value Outstanding	39,246		'	'
Aggregate Intrinsic Value, SARs exercisable	$33,466		'	'
Weighted Average Fair Value per Award Granted	'		$10.66	11.2
[1]	Includes shares available for SARs, restricted stock and performance share grants.

Capitalization_And_ShortTerm_B5

Capitalization And Short-Term Borrowings (Schedule Of Share-Based Compensation For Restricted Stock Units) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Restricted Share Awards [Member]	'	'	'
Schedule of Capitalization [Line Items]	'	'	'
Number of Shares Outstanding, Beginning of Year	127,453	'	'
Number of Shares Granted	0	0	41,525
Number of Awards Vested	-34,601	'	'
Number of Shares Forfeited	-3,334	'	'
Number of Shares Outstanding, End of Year	89,518	127,453	'
Weighted Average Fair Value per Award, Beginning of Year	$51.69	'	'
Weighted Average Fair Value per Award Granted	$0	'	$55.09
Weighted Average Fair Value per Award Vested	$58.17	'	'
Weighted Average Fair Value per Award Forfeited	$55.09	'	'
Weighted Average Fair Value per Award, End of Year	$49.05	$51.69	'
Non-Performance Based Restricted Stock Units (RSUs) [Member]	'	'	'
Schedule of Capitalization [Line Items]	'	'	'
Number of Shares Outstanding, Beginning of Year	143,500	'	'
Number of Shares Granted	82,151	44,200	68,450
Number of Awards Vested	-12,432	'	'
Number of Shares Forfeited	-8,700	'	'
Number of Shares Outstanding, End of Year	204,519	143,500	'
Weighted Average Fair Value per Award, Beginning of Year	$51.53	'	'
Weighted Average Fair Value per Award Granted	$65.24	$51.11	$47.10
Weighted Average Fair Value per Award Vested	$60.54	'	'
Weighted Average Fair Value per Award Forfeited	$54.53	'	'
Weighted Average Fair Value per Award, End of Year	$56.36	$51.53	'
Performance Based Restricted Stock Units (RSUs) [Member]	'	'	'
Schedule of Capitalization [Line Items]	'	'	'
Number of Shares Outstanding, Beginning of Year	255,604	'	'
Number of Shares Granted	0	255,604	0
Number of Awards Vested	0	'	'
Number of Shares Forfeited	-21,728	'	'
Number of Shares Outstanding, End of Year	233,876	255,604	'
Weighted Average Fair Value per Award, Beginning of Year	$49.51	'	'
Weighted Average Fair Value per Award Granted	$0	$49.51	'
Weighted Average Fair Value per Award Vested	$0	'	'
Weighted Average Fair Value per Award Forfeited	$48.49	'	'
Weighted Average Fair Value per Award, End of Year	$49.61	$49.51	'

Capitalization_And_ShortTerm_B6

Capitalization And Short-Term Borrowings (Weighted Average Assumptions Used In Estimating Fair Value) (Details)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
	Performance Shares [Member]	Stock Appreciation Rights (SARs) [Member]	Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk Free Interest Rate	0.62%	1.55%	1.59%
Expected Life (Years)	'	'8 years 3 months	'8 years 3 months
Remaining Term at Date of Grant (Years)	'2 years 9 months 12 days	'	'
Expected Volatility	28.30%	25.61%	24.97%
Expected Dividend Yield (Quarterly)	'	0.69%	0.64%

Capitalization_And_ShortTerm_B7

Capitalization And Short-Term Borrowings (Schedule Of Long-Term Debt) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Debt Instrument [Line Items]	'		'
Total Long-Term Debt	$1,649,000		$1,649,000
Less Current Portion	0	[1]	0	[1]
Long-term debt, excluding current portion	1,649,000		1,649,000
7.4% Due March 2023 To June 2025 [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt interest rate, minimum	7.40%		'
Medium-Term Notes	99,000	[2]	99,000	[2]
3.75% To 8.75% Due April 2018 To March 2023 [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt interest rate, minimum	3.75%		'
Debt interest rate, maximum	8.75%		'
Notes	$1,550,000	[2],[3]	$1,550,000	[2],[3]
Percentage of principal amount	101.00%		101.00%
[1]	None of the Company’s long-term debt at September 30, 2014 and 2013 will mature within the following twelve-month period.
[2]	The Medium-Term Notes and Notes are unsecured.
[3]	The holders of these notes may require the Company to repurchase their notes at a price equal to 101% of the principal amount in the event of both a change in control and a ratings downgrade to a rating below investment grade.

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Hedging collateral deposits	$2,734,000	[1]	$1,094,000	[1]
Assumed 12 month Midway Sunset Oil comparison to NYMEX	98.20%		'
Assumed 12 month minimum Midway Sunset Oil comparison to NYMEX	95.30%		'
Assumed 12 month maximum Midway Sunset Oil comparison to NYMEX	100.60%		'
Fair value measured on recurring basis, net	140,790,000	[1]	139,452,000	[1]
Benefit assets transferred	0		0
Derivative Financial Instruments [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Benefit assets transferred	0		0
Sales of Derivative Financial Instruments	0		0
Purchases of Derivative Financial Instruments	0		0
Fair Value, Inputs, Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Hedging collateral deposits	2,734,000		1,094,000
Fair value measured on recurring basis, net	68,994,000		92,024,000
Fair Value, Inputs, Level 1 [Member] | Futures [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Hedging collateral deposits	2,700,000		1,100,000
Fair Value, Inputs, Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Hedging collateral deposits	0		0
Fair value measured on recurring basis, net	1,368,000		-5,190,000
Fair Value, Inputs, Level 3 [Member] | Over The Counter Swaps - Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value measured on recurring basis, net	1,400,000		'
Lower [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Midway Sunset Oil Comparison to NYMEX Sensitivity percentage points	10.00%		'
Lower [Member] | Fair Value, Inputs, Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of crude oil price swap sensitivity	2,600,000		'
Higher [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Midway Sunset Oil Comparison to NYMEX Sensitivity percentage points	10.00%		'
Higher [Member] | Fair Value, Inputs, Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fair value of crude oil price swap sensitivity	($1,200,000)		'
[1]	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

Fair_Value_Measurements_Recurr

Fair Value Measurements (Recurring Fair Value Measures Of Assets And Liabilities) (Details) (USD $)	Sep. 30, 2014		Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Cash Equivalents - Money Market Mutual Funds	$23,794,000	[1]	$51,332,000	[1]
Hedging Collateral Deposits	2,734,000	[1]	1,094,000	[1]
Total Assets	141,549,000	[1]	140,091,000	[1]
Total Liabilities	759,000	[1]	639,000	[1]
Total Net Assets/(Liabilities)	140,790,000	[1]	139,452,000	[1]
Commodity Futures Contracts - Gas [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	738,000	[1]	911,000	[1]
Derivative Financial Instruments	687,000	[1]	0	[1]
Over Counter Swaps Gas And Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	71,868,000	[1]	48,067,000	[1]
Derivative Financial Instruments	72,000	[1]	639,000	[1]
Balanced Equity Mutual Fund [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	35,331,000	[1]	31,813,000	[1]
Common Stock - Financial Services Industry [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	6,629,000	[1]	6,544,000	[1]
Other Common Stock [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	455,000	[1]	330,000	[1]
Fair Value, Inputs, Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Cash Equivalents - Money Market Mutual Funds	23,794,000		51,332,000
Hedging Collateral Deposits	2,734,000		1,094,000
Total Assets	71,668,000		93,665,000
Total Liabilities	2,674,000		1,641,000
Total Net Assets/(Liabilities)	68,994,000		92,024,000
Fair Value, Inputs, Level 1 [Member] | Commodity Futures Contracts - Gas [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	2,725,000		2,552,000
Derivative Financial Instruments	2,674,000		1,641,000
Fair Value, Inputs, Level 1 [Member] | Over Counter Swaps Gas And Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	0		0
Derivative Financial Instruments	0		0
Fair Value, Inputs, Level 1 [Member] | Balanced Equity Mutual Fund [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	35,331,000		31,813,000
Fair Value, Inputs, Level 1 [Member] | Common Stock - Financial Services Industry [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	6,629,000		6,544,000
Fair Value, Inputs, Level 1 [Member] | Other Common Stock [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	455,000		330,000
Fair Value, Inputs, Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Cash Equivalents - Money Market Mutual Funds	0		0
Hedging Collateral Deposits	0		0
Total Assets	75,951,000		57,070,000
Total Liabilities	5,523,000		4,452,000
Total Net Assets/(Liabilities)	70,428,000		52,618,000
Fair Value, Inputs, Level 2 [Member] | Commodity Futures Contracts - Gas [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	0		0
Derivative Financial Instruments	0		0
Fair Value, Inputs, Level 2 [Member] | Over Counter Swaps Gas And Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	75,951,000		57,070,000
Derivative Financial Instruments	5,523,000		4,452,000
Fair Value, Inputs, Level 2 [Member] | Balanced Equity Mutual Fund [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Fair Value, Inputs, Level 2 [Member] | Common Stock - Financial Services Industry [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Fair Value, Inputs, Level 2 [Member] | Other Common Stock [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Fair Value, Inputs, Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Cash Equivalents - Money Market Mutual Funds	0		0
Hedging Collateral Deposits	0		0
Total Assets	1,368,000		0
Total Liabilities	0		5,190,000
Total Net Assets/(Liabilities)	1,368,000		-5,190,000
Fair Value, Inputs, Level 3 [Member] | Commodity Futures Contracts - Gas [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	0		0
Derivative Financial Instruments	0		0
Fair Value, Inputs, Level 3 [Member] | Over Counter Swaps Gas And Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	1,368,000		0
Derivative Financial Instruments	0		5,190,000
Fair Value, Inputs, Level 3 [Member] | Balanced Equity Mutual Fund [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Common Stock - Financial Services Industry [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Fair Value, Inputs, Level 3 [Member] | Other Common Stock [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0		0
Netting Adjustments [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Cash Equivalents - Money Market Mutual Funds	0	[1]	0	[1]
Hedging Collateral Deposits	0	[1]	0	[1]
Total Assets	-7,438,000	[1]	-10,644,000	[1]
Total Liabilities	-7,438,000	[1]	-10,644,000	[1]
Total Net Assets/(Liabilities)	0	[1]	0	[1]
Netting Adjustments [Member] | Commodity Futures Contracts - Gas [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	-1,987,000	[1]	-1,641,000	[1]
Derivative Financial Instruments	-1,987,000	[1]	-1,641,000	[1]
Netting Adjustments [Member] | Over Counter Swaps Gas And Oil [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Derivative Financial Instruments	-5,451,000	[1]	-9,003,000	[1]
Derivative Financial Instruments	-5,451,000	[1]	-9,003,000	[1]
Netting Adjustments [Member] | Balanced Equity Mutual Fund [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0	[1]	0	[1]
Netting Adjustments [Member] | Common Stock - Financial Services Industry [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	0	[1]	0	[1]
Netting Adjustments [Member] | Other Common Stock [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'		'
Other Investments	$0	[1]	$0	[1]
[1]	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements Using Unobservable Inputs (Level 3)) (Details) (Derivative Financial Instruments [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Derivative Financial Instruments [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Balance, Beginning of Year	($5,190)	[1]	($19,664)	[1]
Total Gains/Losses, Realized and Included in Earnings	2,217	[1],[2]	13,408	[1],[3]
Total Gains/Losses, Unrealized and Included in Other Comprehensive Income (Loss)	4,341	[1]	1,066	[1]
Transfer In/(Out) of Level 3	0	[1]	0	[1]
Balance, End of Year	$1,368	[1]	($5,190)	[1]
[1]	Derivative Financial Instruments are shown on a net basis.
[2]	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2014.
[3]	Amounts are reported in Operating Revenues in the Consolidated Statement of Income for the year ended September 30, 2013.

Financial_Instruments_Narrativ

Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Cash Surrender Value of Life Insurance	$44,400,000		$57,600,000
Net hedging gains (losses) in accumulated other comprehensive income (loss)	76,100,000		'
After tax net hedging gains (losses) in accumulated other comprehensive income (loss)	43,700,000		'
Pre-tax Net hedging gains (losses) reclassified within twelve months	41,100,000		'
After tax Net hedging gains (losses) reclassified within twelve months	23,600,000		'
Pre-Tax Net Hedging Gain (Losses) Reclassified After Twelve Months	35,000,000		'
After Tax Net Hedging Gains (Losses) Reclassified After Twelve Months	20,100,000		'
Number of counterparties in which the company holds over-the-counter swap positions	16		'
Number of counterparties in net gain position	14		'
Collateral Received from Counterparties by the Company	0		'
Fair market value of derivative asset with a credit-risk related contingency	60,100,000		'
Fair market value of derivative liability with a credit-risk related contingency	100,000		'
Hedging collateral deposits	2,734,000	[1]	1,094,000	[1]
Equity Mutual Fund [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Fair value	35,300,000		31,800,000
Gross unrealized gain	8,400,000		5,700,000
Insurance Company Stock [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Fair value	6,600,000		6,500,000
Gross unrealized gain	4,500,000		4,100,000
Over-The-Counter Swap Position [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Credit risk exposure per counterparty	5,100,000		'
Maximum credit risk exposure per counterparty	18,700,000		'
Hedging collateral deposits	0		'
Over-The-Counter Swap Position [Member] | Credit Risk Related Contingency Feature [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Number of counterparties with a common credit-risk related contingency	11		'
Fixed Price Purchase Commitments MMCf [Member] | Energy Marketing [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk fair value hedge derivatives, natural gas	200		'
Exchange-Traded Futures Contracts [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Hedging collateral deposits	2,700,000		'
Fair Value Hedges MMCf [Member] | Energy Marketing [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk fair value hedge derivatives, natural gas	16,100		'
Fixed Price Sales Commitments MMCf [Member] | Energy Marketing [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk fair value hedge derivatives, natural gas	15,800		'
Fixed Price Commitments Related To Withdrawal Of Storage Gas MMCf [Member] | Energy Marketing [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk fair value hedge derivatives, natural gas	100		'
Over The Counter Swaps - Oil [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Derivative loss	($100,000)		($3,700,000)
Cash Flow Hedges Short Position [Member] | Natural Gas MMCf [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk cash flow hedge derivatives, natural gas	212,100		'
Cash Flow Hedges Short Position [Member] | Crude Oil Bbls [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk cash flow hedge derivative, crude oil	3,285,000		'
Cash Flow Hedges Long Position [Member] | Natural Gas MMCf [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Nonmonetary notional amount of price risk cash flow hedge derivatives, natural gas	3,300		'
[1]	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

Financial_Instruments_LongTerm

Financial Instruments (Long-Term Debt) (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Financial Instruments, Owned, at Fair Value [Abstract]	'	'
Carrying Amount	$1,649,000	$1,649,000
Fair Value	$1,775,715	$1,767,519

Financial_Instruments_Schedule

Financial Instruments (Schedule Of Derivatives Financial Instruments Designated And Qualifying As Cash Flow Hedges On The Statements Of Financial Performance) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) (Effective Portion)	$5,334	$91,790	($7,248)
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income (Effective Portion)	-17,647	36,029	'
Derivative Gain or (Loss) Recognized in the Consolidated Statement of Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	624	-2,045	'
Operating Revenues [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) (Effective Portion)	9,763	87,813	'
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income (Effective Portion)	-14,880	36,949	'
Derivative Gain or (Loss) Recognized in the Consolidated Statement of Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	624	-2,045	'
Purchased Gas [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) (Effective Portion)	-4,429	3,977	'
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income (Effective Portion)	-2,767	-920	'
Derivative Gain or (Loss) Recognized in the Consolidated Statement of Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$0	$0	'

Financial_Instruments_Schedule1

Financial Instruments (Schedule Of Derivatives And Hedged Items In Fair Value Hedging Relationships) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]	'
Amount of Gain or (Loss) on Derivative Recognized in the Consolidated Statement of Income	$122
Amount of Gain or (Loss) on Hedged Item Recognized in the Consolidated Statement of Income	-122
Operating Revenues [Member]	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Amount of Gain or (Loss) on Derivative Recognized in the Consolidated Statement of Income	696
Amount of Gain or (Loss) on Hedged Item Recognized in the Consolidated Statement of Income	-696
Purchased Gas [Member]	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Amount of Gain or (Loss) on Derivative Recognized in the Consolidated Statement of Income	-574
Amount of Gain or (Loss) on Hedged Item Recognized in the Consolidated Statement of Income	$574

Retirement_Plan_And_Other_Post2

Retirement Plan And Other Post-Retirement Benefits (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Decrease to accumulated other comprehensive loss	($27,105,000)	($132,024,000)	$86,676,000	'
Expected future benefit payments in year one	59,400,000	'	'	'
Expected future benefit payments in year two	60,400,000	'	'	'
Expected future benefit payments in year three	61,300,000	'	'	'
Expected future benefit payments in year four	62,200,000	'	'	'
Expected future benefit payments in year five	62,900,000	'	'	'
Expected future benefit payments in five years thereafter	326,200,000	'	'	'
Effect of one percentage point increase on accumulated postretirement benefit obligation	53,000,000	'	'	'
Effect of one percentage point increase on service and interest cost components	3,300,000	'	'	'
Effect of one percentage point decrease on accumulated postretirement benefit obligation	44,600,000	'	'	'
Effect of one percentage point decrease on service and interest cost components	2,800,000	'	'	'
Benefit assets transferred	0	0	'	'
Benefit assets transferred in/out of Level 3	0	0	'	'
Retirement Savings Account [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Costs Recognized	1,900,000	1,200,000	900,000	'
Tax-Deferred Savings Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Costs Recognized	5,200,000	4,400,000	4,300,000	'
Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Net periodic benefit cost	39,955,000	37,606,000	29,011,000	'
Accumulated benefit obligation	940,068,000	886,942,000	986,223,000	'
Benefit obligation	999,499,000	946,305,000	1,070,744,000	949,777,000
Discount rate	4.25%	4.75%	3.50%	'
Rate of compensation increase	4.75%	4.75%	4.75%	'
Employer Contributions	33,500,000	54,000,000	44,022,000	'
Expected long term rate of return on plan assets	8.00%	8.00%	8.25%	'
Other Post-Retirement Benefit Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Net periodic benefit cost	10,593,000	21,651,000	24,451,000	'
Benefit obligation	465,583,000	460,634,000	561,263,000	485,452,000
Discount rate	4.25%	4.75%	3.50%	'
Rate of compensation increase	4.75%	4.75%	4.75%	'
Employer Contributions	2,115,000	18,160,000	21,348,000	'
Expected future benefit payments in year one	25,594,000	'	'	'
Expected future benefit payments in year two	26,909,000	'	'	'
Expected future benefit payments in year three	28,113,000	'	'	'
Expected future benefit payments in year four	29,226,000	'	'	'
Expected future benefit payments in year five	30,173,000	'	'	'
Expected future benefit payments in five years thereafter	163,470,000	'	'	'
Expected long term rate of return on plan assets	8.00%	8.00%	8.25%	'
Non-Qualified Benefit Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Net periodic benefit cost	7,500,000	9,600,000	9,100,000	'
Accumulated benefit obligation	65,700,000	57,200,000	54,500,000	'
Benefit obligation	85,500,000	77,100,000	88,500,000	'
Discount rate	3.50%	3.75%	2.50%	'
Rate of compensation increase	7.50%	7.75%	7.75%	'
VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Employer Contributions	2,000,000	'	'	'
Other Than Veba Trust And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Employer Contributions	100,000	'	'	'
Retirement Plan And Other Post-Retirement Benefit Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Discount rate	4.25%	'	'	'
Non-Qualified Benefit Plans, Other Post-Retirement Benefit Plan And Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Decrease in other regulatory assets	19,200,000	'	'	'
Decrease to accumulated other comprehensive loss	900,000	'	'	'
Equity Securities [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	40.00%	'	'	'
Target allocation, maximum	60.00%	'	'	'
Equity Securities [Member] | VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	40.00%	'	'	'
Target allocation, maximum	60.00%	'	'	'
Fixed Income Funds [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	35.00%	'	'	'
Target allocation, maximum	55.00%	'	'	'
Fixed Income Funds [Member] | VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	40.00%	'	'	'
Target allocation, maximum	60.00%	'	'	'
Other Securities [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	5.00%	'	'	'
Target allocation, maximum	20.00%	'	'	'
Other Securities [Member] | VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Target allocation, minimum	0.00%	'	'	'
Target allocation, maximum	15.00%	'	'	'
Actuarial Experience [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Increase (decrease) in benefit obligation	200,000	'	'	'
Actuarial Experience [Member] | Other Post-Retirement Benefit Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Increase (decrease) in benefit obligation	-25,300,000	-28,600,000	6,100,000	'
Discount Rate Change [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Increase (decrease) in benefit obligation	53,700,000	-147,900,000	118,800,000	'
Discount Rate Change [Member] | Other Post-Retirement Benefit Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Increase (decrease) in benefit obligation	26,400,000	-75,900,000	65,600,000	'
Minimum [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Estimated future employer contributions in next fiscal year	15,000,000	'	'	'
Minimum [Member] | VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Estimated future employer contributions in next fiscal year	2,000,000	'	'	'
Maximum [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Estimated future employer contributions in next fiscal year	25,000,000	'	'	'
Maximum [Member] | VEBA Trusts And 401(h) Accounts [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Estimated future employer contributions in next fiscal year	$5,000,000	'	'	'
Effective Fiscal 2015 [Member] | Retirement Plan [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Expected long term rate of return on plan assets	7.50%	'	'	'
Effective Fiscal 2015 [Member] | Other Post-Retirement Benefit Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Expected long term rate of return on plan assets	7.00%	'	'	'

Retirement_Plan_And_Other_Post3

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Benefit Obligations, Plan Assets And Funded Status) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Non-Current Assets	$36,512		$22,774		'
Amortization period	'10 years		'		'
Retirement Plan [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Benefit Obligation at Beginning of Period	946,305		1,070,744		949,777
Service Cost	11,987		15,846		14,202
Interest Cost	43,574		36,498		41,526
Plan Participants' Contributions	0		0		0
Retiree Drug Subsidy Receipts	0		0		0
Actuarial (Gain) Loss	53,887		-121,631		120,338
Benefits Paid	-56,254		-55,152		-55,099
Benefit Obligation at End of Period	999,499		946,305		1,070,744
Fair Value of Assets at Beginning of Period	799,307		701,676		601,719
Actual Return on Plan Assets	93,238		98,783		111,034
Employer Contributions	33,500		54,000		44,022
Fair Value of Assets at End of Period	869,791		799,307		701,676
Net Amount Recognized at End of Period (Funded Status)	-129,708		-146,998		-369,068
Non-Current Liabilities	-129,708		-146,998		-369,068
Non-Current Assets	0		0		0
Accumulated Benefit Obligation	940,068		886,942		986,223
Discount Rate	4.25%		4.75%		3.50%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Expected Return on Plan Assets	-59,974		-57,346		-59,701
Amortization of Prior Service Cost (Credit)	210		238		269
Amortization of Transition Amount	0		0		0
Recognition of Actuarial Loss	36,007	[1]	52,776	[1]	39,615	[1]
Net Amortization and Deferral for Regulatory Purposes	8,151		-10,406		-6,900
Net Periodic Benefit Cost	39,955		37,606		29,011
Discount Rate	4.75%		3.50%		4.50%
Expected Return on Plan Assets	8.00%		8.00%		8.25%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Other Post-Retirement Benefit Plans [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Benefit Obligation at Beginning of Period	460,634		561,263		485,452
Service Cost	2,939		4,705		4,016
Interest Cost	21,308		19,212		21,315
Plan Participants' Contributions	2,265		2,141		1,956
Retiree Drug Subsidy Receipts	1,419		1,526		1,528
Actuarial (Gain) Loss	1,087		-104,455		71,708
Benefits Paid	-24,069		-23,758		-24,712
Benefit Obligation at End of Period	465,583		460,634		561,263
Fair Value of Assets at Beginning of Period	472,392		414,134		351,990
Actual Return on Plan Assets	44,898		61,715		63,552
Employer Contributions	2,115		18,160		21,348
Fair Value of Assets at End of Period	497,601		472,392		414,134
Net Amount Recognized at End of Period (Funded Status)	32,018		11,758		-147,129
Non-Current Liabilities	-4,494		-11,016		-147,129
Non-Current Assets	36,512		22,774		0
Discount Rate	4.25%		4.75%		3.50%
Rate of Compensation Increase	4.75%		4.75%		4.75%
Expected Return on Plan Assets	-37,424		-32,872		-28,971
Amortization of Prior Service Cost (Credit)	-2,138		-2,138		-2,138
Amortization of Transition Amount	0		8		10
Recognition of Actuarial Loss	2,645	[1]	20,892	[1]	24,057	[1]
Net Amortization and Deferral for Regulatory Purposes	23,263		11,844		6,162
Net Periodic Benefit Cost	$10,593		$21,651		$24,451
Discount Rate	4.75%		3.50%		4.50%
Expected Return on Plan Assets	8.00%		8.00%		8.25%
Rate of Compensation Increase	4.75%		4.75%		4.75%
[1]	Distribution Corporation’s New York jurisdiction calculates the amortization of the actuarial loss on a vintage year basis over 10 years, as mandated by the NYPSC. All the other subsidiaries of the Company utilize the corridor approach.

Retirement_Plan_And_Other_Post4

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Cumulative Amounts Recognized In AOCI (Loss) And Regulatory Assets And Liabilities) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Retirement Plan [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Net Actuarial Loss	($226,897)	[1]
Prior Service (Cost) Credit	-856	[1]
Net Amount Recognized	-227,753	[1]
Decrease (Increase) in Actuarial Loss, excluding amortization	-20,622	[1],[2]
Change due to Amortization of Actuarial Loss	36,007	[1]
Prior Service (Cost) Credit	210	[1]
Net Change	15,595	[1]
Net Actuarial Loss	-36,129	[1]
Prior Service (Cost) Credit	-183	[1]
Net Amount Expected to be Recognized	-36,312	[1]
Other Post-Retirement Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Net Actuarial Loss	-32,082	[1]
Prior Service (Cost) Credit	6,940	[1]
Net Amount Recognized	-25,142	[1]
Decrease (Increase) in Actuarial Loss, excluding amortization	6,387	[1],[2]
Change due to Amortization of Actuarial Loss	2,645	[1]
Prior Service (Cost) Credit	-2,138	[1]
Net Change	6,894	[1]
Net Actuarial Loss	-4,148	[1]
Prior Service (Cost) Credit	1,913	[1]
Net Amount Expected to be Recognized	-2,235	[1]
Non Qualified Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Net Actuarial Loss	-23,532	[1]
Prior Service (Cost) Credit	0	[1]
Net Amount Recognized	-23,532	[1]
Decrease (Increase) in Actuarial Loss, excluding amortization	-5,424	[1],[2]
Change due to Amortization of Actuarial Loss	3,008	[1]
Prior Service (Cost) Credit	0	[1]
Net Change	-2,416	[1]
Net Actuarial Loss	-2,925	[1]
Prior Service (Cost) Credit	0	[1]
Net Amount Expected to be Recognized	($2,925)	[1]
[1]	Amounts presented are shown before recognizing deferred taxes.
[2]	Amounts presented include the impact of actuarial gains/losses related to return on assets, as well as the Actuarial (Gain) Loss amounts presented in the Change in Benefit Obligation.

Retirement_Plan_And_Other_Post5

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Expected Benefit Payments) (Details) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'
2015 - Benefit Payments	$59,400
2016 - Benefit Payments	60,400
2017 - Benefit Payments	61,300
2018 - Benefit Payments	62,200
2019 - Benefit Payments	62,900
2020 through 2024 - Benefit Payments	326,200
Other Post-Retirement Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2015 - Benefit Payments	25,594
2015 - Subsidy Receipts	-1,955
2016 - Benefit Payments	26,909
2016 - Subsidy Receipts	-2,143
2017 - Benefit Payments	28,113
2017 - Subsidy Receipts	-2,323
2018 - Benefit Payments	29,226
2018 - Subsidy Receipts	-2,511
2019 - Benefit Payments	30,173
2019 - Subsidy Receipts	-2,708
2020 through 2024 - Benefit Payments	163,470
2020 through 2024 - Subsidy Receipts	($16,104)

Retirement_Plan_And_Other_Post6

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Health Care Cost Trend Rates) (Details)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Compensation and Retirement Disclosure [Abstract]	'		'		'
Rate of Increase for Pre Age 65 Participants	7.10%	[1]	7.28%	[1]	7.46%	[1]
Rate of Increase for Post Age 65 Participants	6.73%	[1]	6.78%	[1]	6.84%	[1]
Annual Rate of Increase in the Per Capita Cost of Covered Prescription Drug Benefits	7.47%	[1]	7.78%	[1]	8.08%	[1]
Annual Rate of Increase in the Per Capita Medicare Part B Reimbursement	6.73%	[1]	6.78%	[1]	6.84%	[1]
Annual Rate of Increase in the Per Capita Medicare Part D Subsidy	6.79%	[1]	7.03%	[1]	7.13%	[1]
Ultimate health care trend rate by 2028	4.50%		'		'
[1]	It was assumed that this rate would gradually decline to 4.5% by 2028.

Retirement_Plan_And_Other_Post7

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Fair Value Of Plan Assets) (Details) (USD $)	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2011
In Thousands, unless otherwise specified
Retirement Plan [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	$869,791		$799,307		$701,676	$601,719
Retirement Plan [Member] | Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	268,649	[1]	402,107	[1]	'	'
Retirement Plan [Member] | International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	80,957	[2]	103,028	[2]	'	'
Retirement Plan [Member] | Global Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	104,238	[3]	25,325	[3]	'	'
Retirement Plan [Member] | Domestic Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	299,494	[4]	163,750	[4]	'	'
Retirement Plan [Member] | International Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	1,240	[5]	2,762	[5]	'	'
Retirement Plan [Member] | Global Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	93,704	[6]	88,084	[6]	'	'
Retirement Plan [Member] | Hedge Funds Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	45,213		42,027		'	'
Retirement Plan [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	3,792		2,723		'	'
Retirement Plan [Member] | Cash And Cash Equivalents [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	33,544		22,694		'	'
Retirement Plan [Member] | Retirement Plan Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	930,831		852,500		'	'
Retirement Plan [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	-54,921		-49,453		'	'
Retirement Plan [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	875,910		803,047		'	'
Other Post-Retirement Benefit Plans [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	497,601		472,392		414,134	351,990
Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	148,219		205,623		'	'
Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	54,881		87,613		'	'
Other Post-Retirement Benefit Plans [Member] | Exchange Traded Funds Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	236,513		122,558		'	'
Other Post-Retirement Benefit Plans [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	'		55		'	'
Other Post-Retirement Benefit Plans [Member] | Cash Held In Collective Trust Funds [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	6,412		11,678		'	'
Other Post-Retirement Benefit Plans [Member] | Total VEBA Trust Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	446,025		427,527		'	'
Other Post-Retirement Benefit Plans [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	54,921		49,453		'	'
Other Post-Retirement Benefit Plans [Member] | Total Investments Including 401H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	500,946		476,980		'	'
Other Post-Retirement Benefit Assets [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	497,601		472,392		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	171,979	[1]	271,071	[1]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	1,969	[2]	2,355	[2]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Global Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[3]	0	[3]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Domestic Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	63,187	[4]	71,185	[4]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | International Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	508	[5]	1,318	[5]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Global Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[6]	0	[6]	'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Hedge Funds Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Cash And Cash Equivalents [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Retirement Plan Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	237,643		345,929		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	-14,105		-20,141		'	'
Fair Value, Inputs, Level 1 [Member] | Retirement Plan [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	223,538		325,788		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Exchange Traded Funds Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	236,513		122,558		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	'		0		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Cash Held In Collective Trust Funds [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Total VEBA Trust Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	236,513		122,558		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	14,105		20,141		'	'
Fair Value, Inputs, Level 1 [Member] | Other Post-Retirement Benefit Plans [Member] | Total Investments Including 401H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	250,618		142,699		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	96,670	[1]	131,036	[1]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	78,988	[2]	100,673	[2]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Global Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	104,238	[3]	25,325	[3]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Domestic Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	236,307	[4]	92,565	[4]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | International Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	732	[5]	1,444	[5]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Global Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	93,704	[6]	88,084	[6]	'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Hedge Funds Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Cash And Cash Equivalents [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	33,544		22,694		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Retirement Plan Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	644,183		461,821		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	-37,907		-26,706		'	'
Fair Value, Inputs, Level 2 [Member] | Retirement Plan [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	606,276		435,115		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	148,219		205,623		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	54,881		87,613		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Exchange Traded Funds Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	'		0		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Cash Held In Collective Trust Funds [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	6,412		11,678		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Total VEBA Trust Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	209,512		304,914		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	37,907		26,706		'	'
Fair Value, Inputs, Level 2 [Member] | Other Post-Retirement Benefit Plans [Member] | Total Investments Including 401H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	247,419		331,620		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[1]	0	[1]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[2]	0	[2]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Global Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[3]	0	[3]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Domestic Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[4]	0	[4]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | International Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[5]	0	[5]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Global Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0	[6]	0	[6]	'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Hedge Funds Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	45,213		42,027		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	3,792		2,723		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Cash And Cash Equivalents [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Retirement Plan Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	49,005		44,750		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	-2,909		-2,606		'	'
Fair Value, Inputs, Level 3 [Member] | Retirement Plan [Member] | Total Retirement Plan Investments Excluding 401 H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	46,096		42,144		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds Domestic Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Collective Trust Funds International Equities [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Exchange Traded Funds Fixed Income [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Real Estate [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	'		55		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Cash Held In Collective Trust Funds [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		0		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Total VEBA Trust Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	0		55		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | 401(h) Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	2,909		2,606		'	'
Fair Value, Inputs, Level 3 [Member] | Other Post-Retirement Benefit Plans [Member] | Total Investments Including 401H Investments [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	2,909		2,661		'	'
Miscellaneous Accruals Including Currentand Deferred Taxes Claims Incurred But Not Reported Administrative [Member] | Other Post-Retirement Benefit Plans [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	-3,345		-4,588		'	'
Miscellaneous Accruals, Interest Receivables, And Non-Interest Cash [Member] | Retirement Plan [Member]	'		'		'	'
Defined Benefit Plan Disclosure [Line Items]	'		'		'	'
Fair Value of Investments	($6,119)		($3,740)		'	'
[1]	Domestic Equities include mostly collective trust funds, common stock, and exchange traded funds.
[2]	International Equities include mostly collective trust funds and common stock.
[3]	Global Equities are comprised of a collective trust fund.
[4]	Domestic Fixed Income securities include mostly collective trust funds, corporate/government bonds and mortgages, and exchange traded funds.
[5]	International Fixed Income securities include mostly collective trust funds and exchange traded funds.
[6]	Global Fixed Income securities are comprised of a collective trust fund.

Retirement_Plan_And_Other_Post8

Retirement Plan And Other Post-Retirement Benefits (Schedule Of Significant Unobservable Input Changes In Plan Assets) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Retirement Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	$42,144,000	$43,446,000
Realized Gains/(Losses)	58,000	-69,000
Unrealized Gains/(Losses)	2,937,000	2,430,000
Purchases	1,046,000	177,000
Sales	-89,000	-3,840,000
Balance, End of Year	46,096,000	42,144,000
Other Post-Retirement Benefit Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	2,661,000	3,985,000
Realized Gains/(Losses)	-36,000	936,000
Unrealized Gains/(Losses)	239,000	541,000
Purchases	65,000	11,000
Sales	-20,000	-2,812,000
Balance, End of Year	2,909,000	2,661,000
Hedge Funds Investments [Member] | Retirement Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	42,027,000	39,956,000
Realized Gains/(Losses)	0	0
Unrealized Gains/(Losses)	3,186,000	2,071,000
Purchases	0	0
Sales	0	0
Balance, End of Year	45,213,000	42,027,000
Real Estate [Member] | Retirement Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	2,723,000	6,170,000
Realized Gains/(Losses)	62,000	-73,000
Unrealized Gains/(Losses)	-10,000	515,000
Purchases	1,111,000	188,000
Sales	-94,000	-4,077,000
Balance, End of Year	3,792,000	2,723,000
Excluding 401(h) Investments [Member] | Retirement Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	-2,606,000	-2,680,000
Realized Gains/(Losses)	-4,000	4,000
Unrealized Gains/(Losses)	-239,000	-156,000
Purchases	-65,000	-11,000
Sales	5,000	237,000
Balance, End of Year	-2,909,000	-2,606,000
VEBA Investments [Member] | Other Post-Retirement Benefit Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	55,000	1,305,000
Realized Gains/(Losses)	-40,000	940,000
Unrealized Gains/(Losses)	0	385,000
Purchases	0	0
Sales	-15,000	-2,575,000
Balance, End of Year	0	55,000
Including 401(h) Investments [Member] | Other Post-Retirement Benefit Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Balance, Beginning of Year	2,606,000	2,680,000
Realized Gains/(Losses)	4,000	-4,000
Unrealized Gains/(Losses)	239,000	156,000
Purchases	65,000	11,000
Sales	-5,000	-237,000
Balance, End of Year	$2,909,000	$2,606,000

Commitments_And_Contingencies_

Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Site Contingency [Line Items]	'
Estimated minimum liability for environmental remediation	14
Future purchase obligation first year	263.8
Future purchase obligation second year	66.7
Future purchase obligation third year	91.8
Future purchase obligation fourth year	91.8
Future purchase obligation fifth year	82.1
Future purchase obligation thereafter year	845.1
Operating lease commitment first year	16
Operating lease commitment second year	5.8
Operating lease commitment third year	5.7
Operating lease commitment fourth year	5.6
Operating lease commitment fifth year	5.3
Operating lease commitment thereafter year	2.4
Mainframe Replacement Project [Member]	'
Site Contingency [Line Items]	'
Contract commitments first year	21
Contract commitments second year	5
Former Manufactured Gas Plant Site [Member]	'
Site Contingency [Line Items]	'
Estimated minimum liability for environmental remediation	12.6
Environmental Site Remediation Costs [Member]	'
Site Contingency [Line Items]	'
Rate recovery period	'13 years
Exploration And Production [Member]	'
Site Contingency [Line Items]	'
Contract commitments first year	95.3
Contract commitments second year	24
Contract commitments third year	0.2
Pipeline And Storage And Gathering Segments [Member]	'
Site Contingency [Line Items]	'
Contract commitments first year	103.9
Contract commitments second year	0.5

Business_Segment_Information_N

Business Segment Information (Narrative) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

segment

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Number of reportable segments

'

'

'

'

'

'

'

'

5

'

'

Segment Profit: Net Income (Loss)

$57,431

$64,520

$95,210

[1]

$82,252

$47,842

[2]

$58,495

$85,720

$67,944

$299,413

$260,001

$220,077

Energy Marketing [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

6,631

4,589

4,169

Energy Marketing [Member] | Unbilled Revenues [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue from External Customers

'

'

'

'

'

'

'

'

8,500

'

'

Energy Marketing [Member] | Margin [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

$600

'

'

[1]

Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.

[2]

Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

Business_Segment_Information_S

Business Segment Information (Segment Information By Segment) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2012

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

$4,170

$4,335

$3,689

Interest Expense

'

'

'

'

'

'

'

'

94,277

94,111

86,240

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

383,781

326,760

271,530

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

189,614

172,758

150,554

Segment Profit: Net Income (Loss)

57,431

64,520

95,210

[1]

82,252

47,842

[2]

58,495

85,720

67,944

299,413

260,001

220,077

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

969,907

717,097

977,394

Segment Assets

6,739,597

'

'

'

6,218,347

'

'

'

6,739,597

6,218,347

5,935,142

Utility [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

3,010

3,417

2,765

Interest Expense

'

'

'

'

'

'

'

'

27,693

29,076

33,181

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

43,594

42,729

42,757

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

33,918

31,065

29,110

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

64,059

65,686

58,590

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

88,810

71,970

58,284

Segment Assets

1,862,850

'

'

'

1,870,587

'

'

'

1,862,850

1,870,587

2,070,413

Pipeline And Storage [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

284

193

199

Interest Expense

'

'

'

'

'

'

'

'

26,428

26,248

25,603

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

36,642

35,156

38,182

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

47,100

38,626

37,655

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

77,559

63,245

60,527

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

139,821

56,144

144,167

Segment Assets

1,367,181

'

'

'

1,246,027

'

'

'

1,367,181

1,246,027

1,243,862

Exploration And Production [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

1,909

1,501

1,493

Interest Expense

'

'

'

'

'

'

'

'

42,232

39,745

29,243

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

296,210

243,431

187,624

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

81,370

95,317

79,050

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

121,569

115,391

96,498

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

602,705

533,129

693,810

Segment Assets

3,100,514

'

'

'

2,746,233

'

'

'

3,100,514

2,746,233

2,367,485

Energy Marketing [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

173

169

188

Interest Expense

'

'

'

'

'

'

'

'

31

36

41

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

197

123

90

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

3,761

2,450

1,933

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

6,631

4,589

4,169

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

264

595

770

Segment Assets

76,238

'

'

'

67,267

'

'

'

76,238

67,267

61,968

Gathering [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

120

55

1

Interest Expense

'

'

'

'

'

'

'

'

1,726

2,283

1,444

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

6,116

3,945

1,691

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

23,636

10,287

4,825

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

32,709

13,321

6,855

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

137,799

54,792

80,012

Segment Assets

326,662

'

'

'

203,323

'

'

'

326,662

203,323

116,756

Total Reportable Segments [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

5,496

5,335

4,646

Interest Expense

'

'

'

'

'

'

'

'

98,110

97,388

89,512

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

382,759

325,384

270,344

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

189,785

177,745

152,573

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

302,527

262,232

226,639

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

969,399

716,630

977,043

Segment Assets

6,733,445

'

'

'

6,133,437

'

'

'

6,733,445

6,133,437

5,860,484

All Other [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

106

115

174

Interest Expense

'

'

'

'

'

'

'

'

6

2

294

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

344

577

400

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

822

529

-490

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

1,160

894

13

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

274

307

5

Segment Assets

86,460

'

'

'

95,793

'

'

'

86,460

95,793

93,178

Corporate And Intersegment Eliminations [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest Income

'

'

'

'

'

'

'

'

-1,432

-1,115

-1,131

Interest Expense

'

'

'

'

'

'

'

'

-3,839

-3,279

-3,566

Depreciation, Depletion and Amortization

'

'

'

'

'

'

'

'

678

799

786

Income Tax Expense (Benefit)

'

'

'

'

'

'

'

'

-993

-5,516

-1,529

Segment Profit: Net Income (Loss)

'

'

'

'

'

'

'

'

-4,274

-3,125

-6,575

Expenditures for Additions to Long-Lived Assets

'

'

'

'

'

'

'

'

234

160

346

Segment Assets

-80,308

'

'

'

-10,883

'

'

'

-80,308

-10,883

-18,520

Revenue From External Customers [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

2,113,081

[3]

1,829,551

[3]

1,626,853

[3]

Revenue From External Customers [Member] | Utility [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

831,156

[3]

730,319

[3]

704,518

[3]

Revenue From External Customers [Member] | Pipeline And Storage [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

200,664

[3]

178,184

[3]

172,312

[3]

Revenue From External Customers [Member] | Exploration And Production [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

804,096

[3]

702,937

[3]

558,180

[3]

Revenue From External Customers [Member] | Energy Marketing [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

271,993

[3]

211,990

[3]

186,579

[3]

Revenue From External Customers [Member] | Gathering [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

673

[3]

1,324

[3]

704

[3]

Revenue From External Customers [Member] | Total Reportable Segments [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

2,108,582

[3]

1,824,754

[3]

1,622,293

[3]

Revenue From External Customers [Member] | All Other [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

3,532

[3]

3,910

[3]

3,603

[3]

Revenue From External Customers [Member] | Corporate And Intersegment Eliminations [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

967

[3]

887

[3]

957

[3]

Intersegment Revenues [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

0

0

0

Intersegment Revenues [Member] | Utility [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

18,462

16,020

14,604

Intersegment Revenues [Member] | Pipeline And Storage [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

83,744

89,424

86,963

Intersegment Revenues [Member] | Exploration And Production [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

0

0

0

Intersegment Revenues [Member] | Energy Marketing [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

1,159

1,384

1,425

Intersegment Revenues [Member] | Gathering [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

69,937

33,457

16,771

Intersegment Revenues [Member] | Total Reportable Segments [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

173,302

140,285

119,763

Intersegment Revenues [Member] | All Other [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

0

0

0

Intersegment Revenues [Member] | Corporate And Intersegment Eliminations [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

($173,302)

($140,285)

($119,763)

[1]

Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.

[2]

Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

[3]

All Revenue from External Customers originated in the United States.

Business_Segment_Information_S1

Business Segment Information (Schedule Of Long-Lived Assets, By Geographical Areas) (Details) (United States [Member], USD $)	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified
United States [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Long-Lived Assets	$6,362,265	$5,769,670	$5,579,566

Quarterly_Financial_Data_Sched

Quarterly Financial Data (Schedule Of Quarterly Financial Information) (Details) (USD $)	3 Months Ended										12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014		Dec. 31, 2013	Sep. 30, 2013		Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Operating Revenues	$366,623,000	$440,144,000	$756,242,000		$550,072,000	$338,863,000		$440,008,000	$597,826,000	$452,854,000	$2,113,081,000	$1,829,551,000	$1,626,853,000
Operating Income	102,004,000	127,013,000	180,075,000		160,581,000	96,636,000		127,004,000	162,991,000	131,207,000	569,673,000	517,838,000	448,049,000
Net Income Available for Common Stock	57,431,000	64,520,000	95,210,000	[1]	82,252,000	47,842,000	[2]	58,495,000	85,720,000	67,944,000	299,413,000	260,001,000	220,077,000
Earnings per Common Share, Basic	$0.68	$0.77	$1.14		$0.98	$0.57		$0.70	$1.03	$0.81	$3.57	$3.11	$2.65
Earnings per Common Share, Diluted	$0.68	$0.76	$1.12		$0.97	$0.57		$0.69	$1.02	$0.81	$3.52	$3.08	$2.63
Corporate Category [Member]	'	'	'		'	'		'	'	'	'	'	'
Death Benefit Gain on Life Insurance Proceeds	'	'	'		'	'		'	3,600,000	'	'	'	'
Utility [Member]	'	'	'		'	'		'	'	'	'	'	'
Net Income Available for Common Stock	'	'	'		'	'		'	'	'	64,059,000	65,686,000	58,590,000
Rate proceeding refund provision	'	'	'		'	$4,700,000		'	'	'	'	'	'
[1]	Includes $3.6 million of income associated with a death benefit gain on life insurance proceeds recorded in the Corporate category.
[2]	Includes a $4.7 million refund provision recorded in the Utility segment related to various issues raised in Distribution Corporation’s rate proceeding in New York.

Market_For_Common_Stock_And_Re2

Market For Common Stock And Related Shareholder Matters (Price Ranges And Dividends Declared) (Details) (USD $)	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
									entity
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'
Number of common stock shareholders	'	'	'	'	'	'	'	'	12,654
Dividends Declared	$0.39	$0.39	$0.38	$0.38	$0.38	$0.38	$0.37	$0.37	'
High [Member]	'	'	'	'	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'
Price Range	$78.79	$78.46	$77.05	$72.53	$69.27	$64.58	$61.44	$55.66	78.79
Low [Member]	'	'	'	'	'	'	'	'	'
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'
Price Range	$65.29	$68.50	$68.12	$65.23	$57.52	$56.80	$48.51	$49	65.29

Supplementary_Information_For_2

Supplementary Information For Oil And Gas Producing Activities (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
	ft3	ft3	ft3
Reserve Quantities [Line Items]	'	'	'	'	'	'
Amount spent for developing proved undeveloped reserves	$179.90	$148.50	$216.60	'	'	'
Increase in Proved undeveloped (PUD) reserve	60,000,000,000	42,000,000,000	'	'	'	'
Percentage of PUD reserves to the total proved reserves	27.00%	29.00%	33.00%	'	'	'
New PUD reserve additions	290,000,000,000	221,000,000,000	'	'	'	'
Proved Undeveloped Reserves, Acquired	20,000,000,000	'	'	'	'	'
Proved Undeveloped Reserve (Volume)	512,000,000,000	452,000,000,000	410,000,000,000	'	'	'
PUD conversions to developed reserves	229,000,000,000	160,000,000,000	'	'	'	'
Proved Undeveloped Reserves, Removed	33,000,000,000	'	'	'	'	'
PUD revisions	12,000,000,000	-19,000,000,000	'	'	'	'
Investment made to convert proved undeveloped reserves to developed reserves	180	149	'	'	'	'
Percentage of PUD reserves booked	'	51.00%	39.00%	33.00%	47.00%	19.00%
Conversion of undeveloped proved reserves to developed proved reserves	229,000,000,000	160,000,000,000	'	'	'	'
Arbitrary discount rate	10.00%	'	'	'	'	'
West Coast Region [Member]	'	'	'	'	'	'
Reserve Quantities [Line Items]	'	'	'	'	'	'
Proved Undeveloped Reserves, Removed	9,000,000,000	'	'	'	'	'
Midway Sunset [Member]	'	'	'	'	'	'
Reserve Quantities [Line Items]	'	'	'	'	'	'
Proved Undeveloped Reserves, Removed	1,501	'	'	'	'	'
Marcellus Shale Fields [Member]	'	'	'	'	'	'
Reserve Quantities [Line Items]	'	'	'	'	'	'
New PUD reserve additions	288,000,000,000	219,000,000,000	'	'	'	'
Proved Undeveloped Reserve (Volume)	504,000,000,000	432,000,000,000	381,000,000,000	'	'	'
Proved Undeveloped Reserves, Removed	24,000,000,000	'	'	'	'	'
Total PUD Reserve Additions Estimated In 2015 [Member]	'	'	'	'	'	'
Reserve Quantities [Line Items]	'	'	'	'	'	'
Amount to be spent on developing proved undeveloped reserves	$239	'	'	'	'	'
Conversion Of Undeveloped Proved Reserves To Developed Proved Reserves Including Revisions [Member]	'	'	'	'	'	'
Reserve Quantities [Line Items]	'	'	'	'	'	'
Conversion of undeveloped proved reserves to developed proved reserves	248,000,000,000	171,000,000,000	'	'	'	'

Supplementary_Information_For_3

Supplementary Information For Oil And Gas Producing Activities (Capitalized Costs Relating To Oil And Gas Producing Activities) (Details) (USD $)	Sep. 30, 2014		Sep. 30, 2013
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'		'
Proved Properties	$3,941,143,000	[1]	$3,393,612,000	[1]
Unproved Properties	141,719,000		106,085,000
Capitalized Costs, Oil and Gas Producing Activities, Gross, Total	4,082,862,000		3,499,697,000
Less - Accumulated Depreciation, Depletion and Amortization	1,211,610,000		919,989,000
Capitalized Costs Oil And Gas Producing Activities Net	2,871,252,000		2,579,708,000
Asset retirement costs	$75,700,000		$80,600,000
[1]	Includes asset retirement costs of $75.7 million and $80.6 million at September 30, 2014 and 2013, respectively.

Supplementary_Information_For_4

Supplementary Information For Oil And Gas Producing Activities (Summary Of Capitalized Costs Of Unproved Properties Excluded From Amortization) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014	Sep. 30, 2011
				Capitalized Costs Of Unproved Properties Cumulative Balance [Member]	Costs Incurred Prior To Fiscal 2012 [Member]
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]	'	'	'	'	'
Acquisition Costs	$7,057	$905	$5,585	$61,712	$48,165
Development Costs	39,339	677	1,405	42,362	941
Exploration Costs	36,882	0	0	36,882	0
Capitalized Interest	763	0	0	763	0
Capitalized Costs of Unproved Properties Excluded from Amortization, Total	$84,041	$1,582	$6,990	$141,719	$49,106

Supplementary_Information_For_5

Supplementary Information For Oil And Gas Producing Activities (Costs Incurred In Oil And Gas Property Acquisition, Exploration And Development Activities) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'		'		'
Proved	$18,213,000		$7,575,000		$13,095,000
Unproved	7,884,000		9,274,000		13,867,000
Exploration Costs	71,850,000	[1]	49,483,000	[1]	84,624,000	[1]
Development Costs	490,164,000	[2]	460,554,000	[2]	576,397,000	[2]
Asset Retirement Costs	-4,946,000		37,546,000		10,344,000
Total Property Acquisition Costs	583,165,000		564,432,000		698,327,000
Capitalized interest included in exploration costs	700,000		400,000		1,000,000
Capitalized interest included in development costs	$700,000		$700,000		$2,000,000
[1]	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.4 million and $1.0 million, respectively.
[2]	Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.7 million and $2.0 million, respectively.

Supplementary_Information_For_6

Supplementary Information For Oil And Gas Producing Activities (Results Of Operations For Producing Activities) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Reserve Quantities [Line Items]	'		'		'
Operating Revenues	$813,259,000	[1]	$663,073,000	[1]	$488,562,000	[1]
Production/Lifting Costs	165,534,000		119,243,000		83,361,000
Franchise/Ad Valorem Taxes	20,765,000		17,200,000		23,620,000
Accretion Expense	6,192,000		3,929,000		3,084,000
Depreciation, Depletion and Amortization ($1.82, $1.98 and $2.19 per Mcfe of production)	291,651,000		238,467,000		182,759,000
Income Tax Expense	140,484,000		120,431,000		81,904,000
Results of Operations for Producing Activities (excluding corporate overheads and interest charges)	188,633,000		163,803,000		113,834,000
Revenues from sales to affiliates	1,000		1,000		1,000
Depreciation, Depletion and Amortization, per Mcfe of Production	1.82		1.98		2.19
Results of Operations, Sales or Transfers to Entity's Other Operations	2,145,000		612,000		0
Natural Gas [Member]	'		'		'
Reserve Quantities [Line Items]	'		'		'
Natural Gas (includes revenues from sales to affiliates of $1 for all years presented and transfers to operations of $2,145, $612 and $0, respectively)	515,080,000		371,311,000		181,544,000
Oil, Condensate And Other Liquids [Member]	'		'		'
Reserve Quantities [Line Items]	'		'		'
Operating Revenues	$298,179,000		$291,762,000		$307,018,000
[1]	Exclusive of hedging gains and losses. See further discussion in Note G — Financial Instruments.

Supplementary_Information_For_7

Supplementary Information For Oil And Gas Producing Activities (Proved Developed And Undeveloped Oil And Gas Reserve Quantities) (Details)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2011
	MMcf		MMcf		MMcf		MMcf
Reserve Quantities [Line Items]	'		'		'		'
Proved Undeveloped Reserve (Volume)	512,000,000,000		452,000,000,000		410,000,000,000		'
Natural Gas (Mmcf) [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	1,299,515		988,434		674,922		'
Extensions and Discoveries	446,821		361,624		436,098		'
Revisions of Previous Estimates	45,048		53,150		-56,455		'
Production Volume	-142,307		-103,693		-66,131		'
Purchases of Minerals in Place	33,986		'		'		'
Sales of Minerals in Place	-179		'		'		'
Proved Developed and Undeveloped Reserves	1,682,884		1,299,515		988,434		'
Proved Developed Reserves (Volume)	1,177,808		866,917		604,483		414,423
Proved Undeveloped Reserve (Volume)	505,076		432,598		383,951		260,499
Oil Mbbl [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	41,598		42,862		43,345		'
Extensions and Discoveries	1,539		2,443		1,257		'
Revisions of Previous Estimates	-1,694		-876		1,130		'
Production Volume	-3,036		-2,831		-2,870		'
Purchases of Minerals in Place	83		'		'		'
Sales of Minerals in Place	-13		'		'		'
Proved Developed and Undeveloped Reserves	38,477		41,598		42,862		'
Proved Developed Reserves (Volume)	37,255		38,365		38,444		37,580
Proved Undeveloped Reserve (Volume)	1,222		3,233		4,418		5,765
West Coast Region [Member] | Natural Gas (Mmcf) [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	60,777		63,023		68,316		'
Extensions and Discoveries	0		702		638		'
Revisions of Previous Estimates	1,358		112		-2,463		'
Production Volume	-3,210		-3,060		-3,468		'
Purchases of Minerals in Place	0		'		'		'
Sales of Minerals in Place	-103		'		'		'
Proved Developed and Undeveloped Reserves	58,822		60,777		63,023		'
Proved Developed Reserves (Volume)	57,907		59,862		59,923		63,965
Proved Undeveloped Reserve (Volume)	915		915		3,100		4,351
West Coast Region [Member] | Oil Mbbl [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	41,315		42,556		43,066		'
Extensions and Discoveries	1,521		2,443		1,229		'
Revisions of Previous Estimates	-1,677		-881		1,095		'
Production Volume	-3,005		-2,803		-2,834		'
Purchases of Minerals in Place	83		'		'		'
Sales of Minerals in Place	-13		'		'		'
Proved Developed and Undeveloped Reserves	38,224		41,315		42,556		'
Proved Developed Reserves (Volume)	37,002		38,082		38,138		37,306
Proved Undeveloped Reserve (Volume)	1,222		3,233		4,418		5,760
Appalachian Region [Member] | Natural Gas (Mmcf) [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	1,238,738		925,411		606,606		'
Extensions and Discoveries	446,821	[1]	360,922	[1]	435,460	[1]	'
Revisions of Previous Estimates	43,690		53,038		-53,992		'
Production Volume	-139,097	[2]	-100,633	[2]	-62,663	[2]	'
Purchases of Minerals in Place	33,986		'		'		'
Sales of Minerals in Place	-76		'		'		'
Proved Developed and Undeveloped Reserves	1,624,062		1,238,738		925,411		'
Proved Developed Reserves (Volume)	1,119,901		807,055		544,560		350,458
Proved Undeveloped Reserve (Volume)	504,161		431,683		380,851		256,148
Appalachian Region [Member] | Oil Mbbl [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Developed and Undeveloped Reserves	283		306		279		'
Extensions and Discoveries	18		0		28		'
Revisions of Previous Estimates	-17		5		35		'
Production Volume	-31		-28		-36		'
Purchases of Minerals in Place	0		'		'		'
Sales of Minerals in Place	0		'		'		'
Proved Developed and Undeveloped Reserves	253		283		306		'
Proved Developed Reserves (Volume)	253		283		306		274
Proved Undeveloped Reserve (Volume)	0		0		0		5
Marcellus Shale Fields [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Proved Undeveloped Reserve (Volume)	504,000,000,000		432,000,000,000		381,000,000,000		'
Marcellus Shale Fields [Member] | Natural Gas (Mmcf) [Member]	'		'		'		'
Reserve Quantities [Line Items]	'		'		'		'
Extensions and Discoveries	442,000		355,000		435,000		'
Production Volume	131,590		93,999		55,812		'
Percentage exceeding total reserve of production in proved developed and undeveloped reserves	15.00%		'		'		'
[1]	Extensions and discoveries include 435 Bcf (during 2012), 355 Bcf (during 2013) and 442 Bcf (during 2014), of Marcellus Shale gas in the Appalachian Region.
[2]	Production includes 55,812 MMcf (during 2012), 93,999 MMcf (during 2013) and 131,590 MMcf (during 2014), from Marcellus Shale fields (which exceed 15% of total reserves).

Supplementary_Information_For_8

Supplementary Information For Oil And Gas Producing Activities (Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves) (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
In Thousands, unless otherwise specified
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'	'	'	'
Future Cash Inflows	$10,001,545	$8,943,942	$7,373,129	'
Future Production Costs	2,795,657	2,334,393	1,919,530	'
Future Development Costs	790,033	749,876	619,573	'
Future Income Tax Expense at Applicable Statutory Rate	2,434,370	2,113,101	1,812,055	'
Future Net Cash Flows	3,981,485	3,746,572	3,021,971	'
10% Annual Discount for Estimated Timing of Cash Flows	1,914,607	1,780,206	1,552,180	'
Standardized Measure of Discounted Future Net Cash Flows	$2,066,878	$1,966,366	$1,469,791	$1,524,157

Supplementary_Information_For_9

Supplementary Information For Oil And Gas Producing Activities (Principal Sources Of Change In The Standardized Measure Of Discounted Future Net Cash Flows) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]	'	'	'
Standardized Measure of Discounted Future Net Cash Flows at Beginning of Year	$1,966,366	$1,469,791	$1,524,157
Sales, Net of Production Costs	-626,960	-526,630	-381,581
Net Changes in Prices, Net of Production Costs	-38,723	339,655	-385,019
Extensions and Discoveries	381,008	390,255	224,474
Changes in Estimated Future Development Costs	68,731	6,117	29,627
Purchases of Minerals in Place	34,705	0	0
Sales of Minerals in Place	-691	0	0
Previously Estimated Development Costs Incurred	179,502	148,535	252,967
Net Change in Income Taxes at Applicable Statutory Rate	-231,807	-130,574	-19,280
Revisions of Previous Quantity Estimates	55,184	34,864	103,472
Accretion of Discount and Other	279,563	234,353	120,974
Standardized Measure of Discounted Future Net Cash Flows at End of Year	$2,066,878	$1,966,366	$1,469,791

Valuation_And_Qualifying_Accou1

Valuation And Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Valuation and Qualifying Accounts [Abstract]	'		'		'
Balance at Beginning of Period	$27,144		$30,317		$31,039
Additions Charged to Costs and Expenses	10,856		5,568		9,183
Additions Charged to Other Accounts	3,241	[1]	2,390	[1]	1,946	[1]
Deductions	9,430	[2]	11,131	[2]	11,851	[2]
Balance at End of Period	$31,811		$27,144		$30,317
[1]	Represents the discount on accounts receivable purchased in accordance with the Utility segment’s 2005 New York rate agreement.
[2]	Amounts represent net accounts receivable written-off.