Atmos Energy (ATO) 10-Q 3 Aug 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Jun. 30, 2016	Jul. 29, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	Atmos Energy Corporation
Entity Central Index Key	731,802
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		103,847,858

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
ASSETS
Property, plant and equipment	$ 9,972,415	$ 9,240,100
Less accumulated depreciation and amortization	1,918,868	1,809,520
Net property, plant and equipment	8,053,547	7,430,580
Current assets
Cash and cash equivalents	66,206	28,653
Accounts receivable, net	277,362	295,160
Gas stored underground	244,841	236,603
Other current assets	60,504	65,890
Total current assets	648,913	626,306
Goodwill	742,702	742,702
Deferred charges and other assets	282,206	293,357
Total assets	9,727,368	9,092,945
Shareholders' equity
Common stock, no par value (stated at $.005 per share)	519	507
Additional paid-in capital	2,371,381	2,230,591
Accumulated other comprehensive income (loss)	(178,233)	(109,330)
Retained earnings	1,273,057	1,073,029
Shareholders' equity	3,466,724	3,194,797
Long-term debt	2,205,645	2,455,388
Total capitalization	5,672,369	5,650,185
Current liabilities
Accounts payable and accrued liabilities	198,882	238,942
Other current liabilities	410,452	457,954
Short-term debt	670,466	457,927
Current maturities of long-term debt	250,000	0
Total current liabilities	1,529,800	1,154,823
Deferred income taxes	1,585,500	1,411,315
Regulatory cost of removal obligation	427,332	427,553
Pension and postretirement liabilities	283,579	287,373
Deferred credits and other liabilities	228,788	161,696
Total shareholders' equity and liabilities	$ 9,727,368	$ 9,092,945

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (PARENTHETICALS) - $ / shares	Jun. 30, 2016	Sep. 30, 2015
Statement of Financial Position [Abstract]
Common Stock, No Par Value	$ 0.005	$ 0.005
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	103,827,358	101,478,818
Common Stock, Shares, Outstanding	103,827,358	101,478,818

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating revenues
Operating revenues	$ 632,916	$ 686,401	$ 2,671,430	$ 3,485,234
Purchased gas cost
Purchased gas cost	225,605	304,728	1,302,545	2,159,538
Gross profit	407,311	381,673	1,368,885	1,325,696
Operating expenses
Operation and maintenance	137,444	132,447	395,958	384,489
Depreciation and amortization	73,459	68,444	216,670	204,059
Taxes, other than income	59,244	63,175	172,872	181,606
Total operating expenses	270,147	264,066	785,500	770,154
Operating income	137,164	117,607	583,385	555,542
Miscellaneous income (expense)	833	634	(1,061)	(2,634)
Interest charges	27,698	27,955	85,741	85,166
Income (loss) before income taxes	110,299	90,286	496,583	467,742
Income tax expense (benefit)	39,106	34,005	180,719	176,182
Net income (loss)	$ 71,193	$ 56,281	$ 315,864	$ 291,560
Basic and diluted net income per share	$ 0.69	$ 0.55	$ 3.06	$ 2.86
Cash dividends per share	$ 0.42	$ 0.39	$ 1.26	$ 1.17
Weighted average shares outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted	103,750	102,000	103,137	101,776
Regulated Distribution Segment [Member]
Operating revenues
Operating revenues	$ 414,226	$ 416,794	$ 1,902,513	$ 2,394,179
Purchased gas cost
Purchased gas cost	138,845	149,775	884,529	1,397,113
Gross profit	275,381	267,019	1,017,984	997,066
Operating expenses
Operation and maintenance	100,859	98,552	291,388	288,962
Depreciation and amortization	58,916	55,491	173,913	165,730
Taxes, other than income	52,377	56,176	152,324	162,759
Total operating expenses	212,152	210,219	617,625	617,451
Operating income	63,229	56,800	400,359	379,615
Miscellaneous income (expense)	1,111	1,045	209	(1,221)
Interest charges	18,968	19,961	58,390	60,914
Income (loss) before income taxes	45,372	37,884	342,178	317,480
Income tax expense (benefit)	15,516	15,420	124,755	121,776
Net income (loss)	29,856	22,464	217,423	195,704
Regulated Pipeline Segment [Member]
Operating revenues
Operating revenues	109,249	97,008	299,629	272,305
Purchased gas cost
Purchased gas cost	0	0	0	0
Gross profit	109,249	97,008	299,629	272,305
Operating expenses
Operation and maintenance	29,083	26,572	83,302	74,029
Depreciation and amortization	13,409	11,816	39,358	34,945
Taxes, other than income	6,220	6,193	18,529	16,296
Total operating expenses	48,712	44,581	141,189	125,270
Operating income	60,537	52,427	158,440	147,035
Miscellaneous income (expense)	(359)	(211)	(1,164)	(842)
Interest charges	9,002	8,299	27,294	25,014
Income (loss) before income taxes	51,176	43,917	129,982	121,179
Income tax expense (benefit)	18,046	15,349	46,081	42,894
Net income (loss)	33,130	28,568	83,901	78,285
Nonregulated Segment [Member]
Operating revenues
Operating revenues	214,555	278,769	774,474	1,179,379
Purchased gas cost
Purchased gas cost	191,741	260,990	722,803	1,122,655
Gross profit	22,814	17,779	51,671	56,724
Operating expenses
Operation and maintenance	7,635	7,456	21,667	21,897
Depreciation and amortization	1,134	1,137	3,399	3,384
Taxes, other than income	647	806	2,019	2,551
Total operating expenses	9,416	9,399	27,085	27,832
Operating income	13,398	8,380	24,586	28,892
Miscellaneous income (expense)	574	345	1,245	897
Interest charges	221	240	1,408	706
Income (loss) before income taxes	13,751	8,485	24,423	29,083
Income tax expense (benefit)	5,544	3,236	9,883	11,512
Net income (loss)	8,207	5,249	14,540	17,571
Intersegment Elimination [Member]
Operating revenues
Operating revenues	(105,114)	(106,170)	(305,186)	(360,629)
Purchased gas cost
Purchased gas cost	(104,981)	(106,037)	(304,787)	(360,230)
Gross profit	(133)	(133)	(399)	(399)
Operating expenses
Operation and maintenance	(133)	(133)	(399)	(399)
Depreciation and amortization	0	0	0	0
Taxes, other than income	0	0	0	0
Total operating expenses	(133)	(133)	(399)	(399)
Operating income	0	0	0	0
Miscellaneous income (expense)	(493)	(545)	(1,351)	(1,468)
Interest charges	(493)	(545)	(1,351)	(1,468)
Income (loss) before income taxes	0	0	0	0
Income tax expense (benefit)	0	0	0	0
Net income (loss)	$ 0	$ 0	$ 0	$ 0

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 71,193	$ 56,281	$ 315,864	$ 291,560
Other comprehensive income (loss), net of tax
Net unrealized holding gains (losses) on available-for-sale securities, net of tax	151	(191)	(1,496)	(296)
Schedule of Other Comprehensive Income (Loss), Cash Flow Hedges [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(21,145)	66,038	(67,407)	(49,552)
Total other comprehensive income (loss)	(20,994)	65,847	(68,903)	(49,848)
Total comprehensive income (loss)	50,199	122,128	246,961	241,712
Interest Rate Contract [Member]
Schedule of Other Comprehensive Income (Loss), Cash Flow Hedges [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(39,250)	54,475	(88,085)	(29,981)
Commodity Contract [Member]
Schedule of Other Comprehensive Income (Loss), Cash Flow Hedges [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	$ 18,105	$ 11,563	$ 20,678	$ (19,571)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (PARENTHETICALS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Comprehensive Income Loss Tax Portion Attributable To Parent Abstract
Unrealized holding gains (losses) on available-for-sale securities, tax	$ 110	$ (41)	$ (837)	$ (170)
Interest Rate Contract [Member]
Schedule of Other Comprehensive Income (Loss), Tax, Cash Flow Hedges [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(22,561)	31,314	(50,631)	(17,232)
Commodity Contract [Member]
Schedule of Other Comprehensive Income (Loss), Tax, Cash Flow Hedges [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	$ 11,575	$ 7,393	$ 13,220	$ (12,698)

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows From Operating Activities
Net income	$ 315,864	$ 291,560
Depreciation and amortization:
Charged to depreciation and amortization	216,670	204,059
Charged to other accounts	983	853
Other
Deferred income taxes	171,042	164,627
Other	19,767	18,146
Net Assets Liabilities From Risk Management Activities	(8,357)	(13,136)
Net change in operating assets and liabilities	(91,371)	51,473
Net cash provided by operating activities	624,598	717,582
Cash Flows From Investing Activities
Capital expenditures	(796,008)	(667,483)
Other, net	1,627	(1,119)
Net cash used in investing activities	(794,381)	(668,602)
Cash Flows From Financing Activities
Net increase in short-term debt	212,539	48,830
Net proceeds from equity offering	98,660	0
Net proceeds from issuance of long-term debt	0	493,538
Settlement of interest rate agreements	0	13,364
Repayments of long-term debt	0	(500,000)
Cash dividends paid	(130,363)	(116,645)
Repurchase of equity awards	0	(7,985)
Issuance of common stock	26,500	20,813
Net cash provided by (used in) financing activities	207,336	(48,085)
Net increase in cash and cash equivalents	37,553	895
Cash and cash equivalents at beginning of period	28,653	42,258
Cash and cash equivalents at end of period	$ 66,206	$ 43,153

Nature of Business

Nature of Business	9 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Atmos Energy Corporation (“Atmos Energy” or the “Company”) and our subsidiaries are engaged primarily in the regulated natural gas distribution and pipeline businesses as well as other nonregulated natural gas businesses. Historically, our regulated businesses have generated over 90 percent of our consolidated net income. Through our regulated distribution business, we deliver natural gas through sales and transportation arrangements to approximately three million residential, commercial, public authority and industrial customers through our six regulated distribution divisions, which at June 30, 2016 , covered service areas located in eight states. In addition, we transport natural gas for others through our distribution system. Our regulated businesses also include our regulated pipeline and storage operations, which include the transportation of natural gas to our North Texas distribution system and the management of our underground storage facilities. Our regulated businesses are subject to federal and state regulation and/or regulation by local authorities in each of the states in which our regulated distribution divisions operate. Our nonregulated businesses operate primarily in the Midwest and Southeast through various wholly-owned subsidiaries of Atmos Energy Holdings, Inc. (AEH). AEH is wholly owned by the Company and based in Houston, Texas. Through AEH, we provide natural gas management and transportation services to municipalities, natural gas distribution companies, including certain divisions of Atmos Energy, and third parties.

Unaudited Financial Information

Unaudited Financial Information	9 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Unaudited Financial Information	Unaudited Financial Information These consolidated interim-period financial statements have been prepared in accordance with accounting principles generally accepted in the United States on the same basis as those used for the Company’s audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . In the opinion of management, all material adjustments (consisting of normal recurring accruals) necessary for a fair presentation have been made to the unaudited consolidated interim-period financial statements. These consolidated interim-period financial statements are condensed as permitted by the instructions to Form 10-Q and should be read in conjunction with the audited consolidated financial statements of Atmos Energy Corporation included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . Because of seasonal and other factors, the results of operations for the nine -month period ended June 30, 2016 are not indicative of our results of operations for the full 2016 fiscal year, which ends September 30, 2016 . No events have occurred subsequent to the balance sheet date that would require recognition or disclosure in the condensed consolidated financial statements. Significant accounting policies Our accounting policies are described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . Certain prior-year amounts have been reclassified to conform with the current year presentation. During the second quarter of fiscal 2016, we completed our annual goodwill impairment assessment. Based on the assessment performed, we determined that our goodwill was not impaired. In May 2014, the Financial Accounting Standards Board (FASB) issued a comprehensive new revenue recognition standard that will supersede virtually all existing revenue recognition guidance under generally accepted accounting principles in the United States. Under the new standard, a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance. The new standard is currently scheduled to become effective for us beginning on October 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. As of June 30, 2016 , we were actively evaluating all of our sources of revenue to determine the potential effect on our financial position, results of operations and cash flows and the transition approach we will utilize. We are also actively monitoring the deliberations of the FASB's Transition Resource Group as decisions made by this group will impact the final conclusions of this evaluation. In April 2015, the FASB issued guidance to simplify the presentation of debt issuance costs, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The new standard will be effective for us beginning on October 1, 2016, and will be applied retrospectively. In November 2015, the FASB issued guidance that requires all deferred income tax liabilities and assets to be presented as noncurrent in a classified balance sheet. Currently, entities are required to separate deferred income tax liabilities and assets into current and noncurrent amounts in a classified balance sheet. As permitted under the new guidance, we elected early adoption as of March 31, 2016. The adoption of this guidance had no impact on our results of operations or cash flows. Because we adopted this new guidance prospectively, prior periods have not been adjusted. In January 2016, the FASB issued guidance related to the classification and measurement of financial instruments. The amendments modify the accounting and presentation for certain financial liabilities and equity investments not consolidated or reported using the equity method. The guidance is effective for us beginning October 1, 2018; limited early adoption is permitted. We are currently evaluating the potential impact of this new guidance. In February 2016, the FASB issued a comprehensive new leasing standard that will require lessees to recognize a lease liability and a right-of-use asset for all leases, including operating leases, with a term greater than 12 months on its balance sheet. The new standard will be effective for us beginning on October 1, 2019; early adoption is permitted. The new leasing standard requires modified retrospective transition, which requires application of the new guidance at the beginning of the earliest comparative period presented in the year of adoption. We are currently evaluating the effect on our financial position, results of operations and cash flows. In March 2016, the FASB issued guidance to simplify the accounting and reporting of share-based payment arrangements. Key modifications required under the new guidance include: • Recognition of all excess tax benefits and tax deficiencies associated with stock-based compensation as income tax expense or benefit in the income statement in the period the awards vest. The guidance also requires these income tax inflows and outflows to be classified as an operating activity. • Simplification of the accounting for forfeitures. • Clarification that cash paid by an employer when directly withholding shares for tax-withholding purposes should be classified as a financing activity. As permitted under the new guidance, we elected early adoption as of March 31, 2016. In accordance with the transition requirements, we recorded a $3.3 million income tax benefit during the first six months of fiscal 2016. Additionally, we recorded a $14.5 million cumulative-effect increase to retained earnings with an offsetting increase to the Company’s net operating loss (NOL) deferred tax asset to recognize the effect of excess tax benefits earned prior to September 30, 2015. For the nine months ended June 30, 2016, we have recognized a total income tax benefit of $4.9 million . Since we have adopted this new guidance prospectively, prior periods have not been adjusted. In June 2016, the FASB issued new guidance which will require credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model. Under this model, entities will estimate credit losses over the entire contractual term of the instrument from the date of initial recognition of that instrument. In contrast, current U.S. GAAP is based on an incurred loss model that delays recognition of credit losses until it is probable the loss has been incurred. The new guidance also introduces a new impairment recognition model for available-for-sale securities that will require credit losses for available-for-sale debt securities to be recorded through an allowance account. The new standard will be effective for us beginning on October 1, 2021; early adoption is permitted beginning on October 1, 2019. We are currently evaluating the potential impact of this new guidance. Regulatory assets and liabilities Accounting principles generally accepted in the United States require cost-based, rate-regulated entities that meet certain criteria to reflect the authorized recovery of costs due to regulatory decisions in their financial statements. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. We record certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. Substantially all of our regulatory assets are recorded as a component of deferred charges and other assets and substantially all of our regulatory liabilities are recorded as a component of deferred credits and other liabilities. Deferred gas costs are recorded either in other current assets or liabilities and the regulatory cost of removal obligation is reported separately. Significant regulatory assets and liabilities as of June 30, 2016 and September 30, 2015 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs (1) $ 110,425 $ 121,183 Infrastructure mechanisms (2) 31,090 32,813 Deferred gas costs 3,390 9,715 Recoverable loss on reacquired debt 14,401 16,319 APT annual adjustment mechanism 2,976 1,002 Rate case costs 1,640 1,533 Other 20,906 9,774 $ 184,828 $ 192,339 Regulatory liabilities: Regulatory cost of removal obligations $ 486,290 $ 483,676 Deferred gas costs 34,362 28,100 Asset retirement obligations 9,063 9,063 Other 5,483 3,693 $ 535,198 $ 524,532 (1) Includes $12.9 million and $16.6 million of pension and postretirement expense deferred pursuant to regulatory authorization. (2) Infrastructure mechanisms in Texas and Louisiana allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consist of interest, depreciation and other taxes, until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates.

Segment Information

Segment Information	9 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information We operate the Company through the following three segments: • The regulated distribution segment , which includes our regulated natural gas distribution and related sales operations, • The regulated pipeline segment , which includes the regulated pipeline and storage operations of our Atmos Pipeline — Texas Division and • The nonregulated segment , which is comprised of our nonregulated natural gas management, nonregulated natural gas transmission, storage and other services. Our determination of reportable segments considers the strategic operating units under which we manage sales of various products and services to customers in differing regulatory environments. Although our regulated distribution segment operations are geographically dispersed, they are reported as a single segment as each regulated distribution division has similar economic characteristics. The accounting policies of the segments are the same as those described in the summary of significant accounting policies found in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . We evaluate performance based on net income or loss of the respective operating units. Income statements for the three and nine months ended June 30, 2016 and 2015 by segment are presented in the following tables: Three Months Ended June 30, 2016 Regulated Distribution Regulated Pipeline Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 411,982 $ 28,518 $ 192,416 $ — $ 632,916 Intersegment revenues 2,244 80,731 22,139 (105,114 ) — 414,226 109,249 214,555 (105,114 ) 632,916 Purchased gas cost 138,845 — 191,741 (104,981 ) 225,605 Gross profit 275,381 109,249 22,814 (133 ) 407,311 Operating expenses Operation and maintenance 100,859 29,083 7,635 (133 ) 137,444 Depreciation and amortization 58,916 13,409 1,134 — 73,459 Taxes, other than income 52,377 6,220 647 — 59,244 Total operating expenses 212,152 48,712 9,416 (133 ) 270,147 Operating income 63,229 60,537 13,398 — 137,164 Miscellaneous income (expense) 1,111 (359 ) 574 (493 ) 833 Interest charges 18,968 9,002 221 (493 ) 27,698 Income before income taxes 45,372 51,176 13,751 — 110,299 Income tax expense 15,516 18,046 5,544 — 39,106 Net income $ 29,856 $ 33,130 $ 8,207 $ — $ 71,193 Capital expenditures $ 191,202 $ 66,639 $ (66 ) $ — $ 257,775 Three Months Ended June 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 415,160 $ 25,859 $ 245,382 $ — $ 686,401 Intersegment revenues 1,634 71,149 33,387 (106,170 ) — 416,794 97,008 278,769 (106,170 ) 686,401 Purchased gas cost 149,775 — 260,990 (106,037 ) 304,728 Gross profit 267,019 97,008 17,779 (133 ) 381,673 Operating expenses Operation and maintenance 98,552 26,572 7,456 (133 ) 132,447 Depreciation and amortization 55,491 11,816 1,137 — 68,444 Taxes, other than income 56,176 6,193 806 — 63,175 Total operating expenses 210,219 44,581 9,399 (133 ) 264,066 Operating income 56,800 52,427 8,380 — 117,607 Miscellaneous income (expense) 1,045 (211 ) 345 (545 ) 634 Interest charges 19,961 8,299 240 (545 ) 27,955 Income before income taxes 37,884 43,917 8,485 — 90,286 Income tax expense 15,420 15,349 3,236 — 34,005 Net income $ 22,464 $ 28,568 $ 5,249 $ — $ 56,281 Capital expenditures $ 170,134 $ 55,914 $ (209 ) $ — $ 225,839 Nine Months Ended June 30, 2016 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 1,896,636 $ 75,344 $ 699,450 $ — $ 2,671,430 Intersegment revenues 5,877 224,285 75,024 (305,186 ) — 1,902,513 299,629 774,474 (305,186 ) 2,671,430 Purchased gas cost 884,529 — 722,803 (304,787 ) 1,302,545 Gross profit 1,017,984 299,629 51,671 (399 ) 1,368,885 Operating expenses Operation and maintenance 291,388 83,302 21,667 (399 ) 395,958 Depreciation and amortization 173,913 39,358 3,399 — 216,670 Taxes, other than income 152,324 18,529 2,019 — 172,872 Total operating expenses 617,625 141,189 27,085 (399 ) 785,500 Operating income 400,359 158,440 24,586 — 583,385 Miscellaneous income (expense) 209 (1,164 ) 1,245 (1,351 ) (1,061 ) Interest charges 58,390 27,294 1,408 (1,351 ) 85,741 Income before income taxes 342,178 129,982 24,423 — 496,583 Income tax expense 124,755 46,081 9,883 — 180,719 Net income $ 217,423 $ 83,901 $ 14,540 $ — $ 315,864 Capital expenditures $ 533,826 $ 262,058 $ 124 $ — $ 796,008 Nine Months Ended June 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 2,389,037 $ 70,887 $ 1,025,310 $ — $ 3,485,234 Intersegment revenues 5,142 201,418 154,069 (360,629 ) — 2,394,179 272,305 1,179,379 (360,629 ) 3,485,234 Purchased gas cost 1,397,113 — 1,122,655 (360,230 ) 2,159,538 Gross profit 997,066 272,305 56,724 (399 ) 1,325,696 Operating expenses Operation and maintenance 288,962 74,029 21,897 (399 ) 384,489 Depreciation and amortization 165,730 34,945 3,384 — 204,059 Taxes, other than income 162,759 16,296 2,551 — 181,606 Total operating expenses 617,451 125,270 27,832 (399 ) 770,154 Operating income 379,615 147,035 28,892 — 555,542 Miscellaneous income (expense) (1,221 ) (842 ) 897 (1,468 ) (2,634 ) Interest charges 60,914 25,014 706 (1,468 ) 85,166 Income before income taxes 317,480 121,179 29,083 — 467,742 Income tax expense 121,776 42,894 11,512 — 176,182 Net income $ 195,704 $ 78,285 $ 17,571 $ — $ 291,560 Capital expenditures $ 482,371 $ 185,028 $ 84 $ — $ 667,483 Balance sheet information at June 30, 2016 and September 30, 2015 by segment is presented in the following tables: June 30, 2016 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) ASSETS Property, plant and equipment, net $ 6,067,548 $ 1,935,087 $ 50,912 $ — $ 8,053,547 Investment in subsidiaries 1,007,787 — — (1,007,787 ) — Current assets Cash and cash equivalents 61,441 — 4,765 — 66,206 Assets from risk management activities 3,651 — 4,047 — 7,698 Other current assets 370,444 22,269 391,265 (208,969 ) 575,009 Intercompany receivables 981,651 — — (981,651 ) — Total current assets 1,417,187 22,269 400,077 (1,190,620 ) 648,913 Goodwill 575,449 132,542 34,711 — 742,702 Noncurrent assets from risk management activities 750 — 908 — 1,658 Deferred charges and other assets 258,370 21,976 202 — 280,548 $ 9,327,091 $ 2,111,874 $ 486,810 $ (2,198,407 ) $ 9,727,368 CAPITALIZATION AND LIABILITIES Shareholders’ equity $ 3,466,724 $ 661,175 $ 346,612 $ (1,007,787 ) $ 3,466,724 Long-term debt 2,205,645 — — — 2,205,645 Total capitalization 5,672,369 661,175 346,612 (1,007,787 ) 5,672,369 Current liabilities Current maturities of long-term debt 250,000 — — — 250,000 Short-term debt 870,466 — — (200,000 ) 670,466 Liabilities from risk management activities 56,883 — — — 56,883 Other current liabilities 453,831 16,590 90,999 (8,969 ) 552,451 Intercompany payables — 953,683 27,968 (981,651 ) — Total current liabilities 1,631,180 970,273 118,967 (1,190,620 ) 1,529,800 Deferred income taxes 1,093,755 480,336 11,409 — 1,585,500 Noncurrent liabilities from risk management activities 176,491 — — — 176,491 Regulatory cost of removal obligation 427,332 — — — 427,332 Pension and postretirement liabilities 283,579 — — — 283,579 Deferred credits and other liabilities 42,385 90 9,822 — 52,297 $ 9,327,091 $ 2,111,874 $ 486,810 $ (2,198,407 ) $ 9,727,368 September 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) ASSETS Property, plant and equipment, net $ 5,670,306 $ 1,706,449 $ 53,825 $ — $ 7,430,580 Investment in subsidiaries 1,038,670 — (2,096 ) (1,036,574 ) — Current assets Cash and cash equivalents 23,863 — 4,790 — 28,653 Assets from risk management activities 378 — 8,854 — 9,232 Other current assets 421,591 24,628 480,503 (338,301 ) 588,421 Intercompany receivables 887,713 — — (887,713 ) — Total current assets 1,333,545 24,628 494,147 (1,226,014 ) 626,306 Goodwill 575,449 132,542 34,711 — 742,702 Noncurrent assets from risk management activities 368 — — — 368 Deferred charges and other assets 270,372 17,288 5,329 — 292,989 $ 8,888,710 $ 1,880,907 $ 585,916 $ (2,262,588 ) $ 9,092,945 CAPITALIZATION AND LIABILITIES Shareholders’ equity $ 3,194,797 $ 577,275 $ 461,395 $ (1,038,670 ) $ 3,194,797 Long-term debt 2,455,388 — — — 2,455,388 Total capitalization 5,650,185 577,275 461,395 (1,038,670 ) 5,650,185 Current liabilities Short-term debt 782,927 — — (325,000 ) 457,927 Liabilities from risk management activities 9,568 — — — 9,568 Other current liabilities 569,273 29,780 99,480 (11,205 ) 687,328 Intercompany payables — 867,409 20,304 (887,713 ) — Total current liabilities 1,361,768 897,189 119,784 (1,223,918 ) 1,154,823 Deferred income taxes 1,008,091 406,254 (3,030 ) — 1,411,315 Noncurrent liabilities from risk management activities 110,539 — — — 110,539 Regulatory cost of removal obligation 427,553 — — — 427,553 Pension and postretirement liabilities 287,373 — — — 287,373 Deferred credits and other liabilities 43,201 189 7,767 — 51,157 $ 8,888,710 $ 1,880,907 $ 585,916 $ (2,262,588 ) $ 9,092,945

Earnings Per Share

Earnings Per Share	9 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share We use the two-class method of computing earnings per share because we have participating securities in the form of non-vested restricted stock units with a nonforfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator. Basic and diluted earnings per share for the three and nine months ended June 30, 2016 and 2015 are calculated as follows: Three Months Ended Nine Months Ended 2016 2015 2016 2015 (In thousands, except per share amounts) Basic and Diluted Earnings Per Share Net income $ 71,193 $ 56,281 $ 315,864 $ 291,560 Less: Income allocated to participating securities 108 111 496 596 Income available to common shareholders $ 71,085 $ 56,170 $ 315,368 $ 290,964 Basic and diluted weighted average shares outstanding 103,750 102,000 103,137 101,776 Net income per share - Basic and Diluted $ 0.69 $ 0.55 $ 3.06 $ 2.86

Debt

Debt	9 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt The nature and terms of our debt instruments and credit facilities are described in detail in Note 5 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . Except as noted below, there were no material changes in the terms of our debt instruments during the nine months ended June 30, 2016 . Long-term debt Long-term debt at June 30, 2016 and September 30, 2015 consisted of the following: June 30, 2016 September 30, 2015 (In thousands) Unsecured 6.35% Senior Notes, due June 2017 $ 250,000 $ 250,000 Unsecured 8.50% Senior Notes, due 2019 450,000 450,000 Unsecured 5.95% Senior Notes, due 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due 2044 500,000 500,000 Medium-term note Series A, 1995-1, 6.67%, due 2025 10,000 10,000 Unsecured 6.75% Debentures, due 2028 150,000 150,000 Total long-term debt 2,460,000 2,460,000 Less: Original issue discount on unsecured senior notes and debentures 4,355 4,612 Current maturities 250,000 — $ 2,205,645 $ 2,455,388 On October 15, 2014 , we issued $500 million of 4.125% 30-year unsecured senior notes, which replaced, on a long-term basis, our $500 million unsecured 4.95% senior notes. The effective rate of these notes is 4.086% , after giving effect to the offering costs and the settlement of the associated forward starting interest rate swaps. The net proceeds of approximately $494 million were used to repay our $500 million 4.95% senior unsecured notes at maturity on October 15, 2014 . Short-term debt Our short-term debt is utilized to fund ongoing working capital needs, such as our seasonal requirements for gas supply, general corporate liquidity and capital expenditures. Our short-term borrowing requirements are affected primarily by the seasonal nature of the natural gas business. Changes in the price of natural gas and the amount of natural gas we need to supply our customers’ needs could significantly affect our borrowing requirements. Our short-term borrowings typically reach their highest levels in the winter months. We currently finance our short-term borrowing requirements through a combination of a $1.25 billion commercial paper program, four committed revolving credit facilities and one uncommitted revolving credit facility with third-party lenders. These facilities provide approximately $1.3 billion of working capital funding. At June 30, 2016 and September 30, 2015 a total of $670.5 million and $457.9 million was outstanding under our commercial paper program. Regulated Operations We fund our regulated operations as needed, primarily through our commercial paper program and three committed revolving credit facilities with third-party lenders that provide approximately $1.3 billion of working capital funding, including a five-year $1.25 billion unsecured facility with an accordion feature, which, if utilized would increase the borrowing capacity to $1.5 billion , a $25 million unsecured facility, which was renewed on April 1, 2016, and a $10 million unsecured revolving credit facility, which is used primarily to issue letters of credit. Due to outstanding letters of credit, the total amount available to us under our $10 million revolving credit facility was $4.1 million at June 30, 2016 . In addition to these third-party facilities, our regulated operations have a $500 million intercompany revolving credit facility with AEH, which bears interest at the lower of (i) the Eurodollar rate under the five-year revolving credit facility or (ii) the lowest rate outstanding under the commercial paper program. Applicable state regulatory commissions have approved our use of this facility through December 31, 2016. Nonregulated Operations Atmos Energy Marketing, LLC (AEM), which is wholly owned by AEH, has one uncommitted $25 million bilateral credit facility that was renewed and extended in March 2016 and one committed $15 million bilateral credit facility that was renewed and extended in December 2015. The uncommitted $25 million bilateral credit facility currently expires in December 2016 and the $15 million bilateral credit facility expires in September 2016. These facilities are used primarily to issue letters of credit. Due to outstanding letters of credit, the total amount available to us under these bilateral credit facilities was $33.0 million at June 30, 2016 . AEH has a $500 million intercompany demand credit facility with AEC. This facility bears interest at a rate equal to the one-month LIBOR rate plus 3.00 percent . Applicable state regulatory commissions have approved our use of this facility through December 31, 2016. Debt Covenants The availability of funds under our regulated credit facilities is subject to conditions specified in the respective credit agreements, all of which we currently satisfy. These conditions include our compliance with financial covenants and the continued accuracy of representations and warranties contained in these agreements. We are required by the financial covenants in each of these facilities to maintain, at the end of each fiscal quarter, a ratio of total debt to total capitalization of no greater than 70 percent . At June 30, 2016 , our total-debt-to-total-capitalization ratio, as defined in the agreements, was 49 percent . In addition, both the interest margin and the fee that we pay on unused amounts under certain of these facilities are subject to adjustment depending upon our credit ratings. In addition to these financial covenants, our credit facilities and public indentures contain usual and customary covenants for our business, including covenants substantially limiting liens, substantial asset sales and mergers. Additionally, our public debt indentures relating to our senior notes and debentures, as well as certain of our revolving credit agreements, each contain a default provision that is triggered if outstanding indebtedness arising out of any other credit agreements in amounts ranging from in excess of $15 million to in excess of $100 million becomes due by acceleration or is not paid at maturity. We were in compliance with all of our debt covenants as of June 30, 2016 . If we were unable to comply with our debt covenants, we would likely be required to repay our outstanding balances on demand, provide additional collateral or take other corrective actions.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Shelf Registration On March 28, 2016, we filed a registration statement with the Securities and Exchange Commission (SEC) that originally permitted us to issue, from time to time, up to $2.5 billion in common stock and/or debt securities, which replaced our registration statement that expired on March 28, 2016. At June 30, 2016 , $2.4 billion of securities remain available for issuance under the shelf registration statement. At-the-Market Equity Sales Program On March 28, 2016, we entered into an at-the-market (ATM) equity distribution agreement (the Agreement) with Goldman, Sachs & Co., Merrill Lynch, Pierce, Fenner & Smith Incorporated and Morgan Stanley & Co. LLC in their capacity as agents and/or as principals (Agents). Under the terms of the Agreement, we may issue and sell, through any of the Agents, shares of our common stock, up to an aggregate offering price of $200 million , through the period ended March 28, 2019. We may also sell shares from time to time to an Agent for its own account at a price to be agreed upon at the time of sale. We will pay each Agent a commission of 1.0% of the gross offering proceeds of the shares sold through it as a sales agent. We have no obligation to offer or sell any shares under the Agreement, and may at any time suspend offers and sales under the Agreement. The shares will be issued pursuant to our shelf registration statement filed with the SEC on March 28, 2016. During the third fiscal quarter of 2016, we sold 1,360,756 shares of common stock under the ATM program for $100.0 million and received net proceeds of $98.7 million . 1998 Long-Term Incentive Plan In August 1998, the Board of Directors approved and adopted the 1998 Long-Term Incentive Plan (LTIP), which became effective in October 1998 after approval by our shareholders. The LTIP is a comprehensive, long-term incentive compensation plan providing for discretionary awards of incentive stock options, non-qualified stock options, stock appreciation rights, bonus stock, time-lapse restricted stock, time-lapse restricted stock units, performance-based restricted stock units and stock units to certain employees and non-employee directors of the Company and our subsidiaries. The objectives of this plan include attracting and retaining the best personnel, providing for additional performance incentives and promoting our success by providing employees with the opportunity to acquire our common stock. As of September 30, 2015, we were authorized to grant awards for up to a maximum of 8.7 million shares of common stock under this plan subject to certain adjustment provisions. In February 2016, our shareholders voted to increase the number of authorized LTIP shares by 2.5 million shares and to extend the term of the plan for an additional five years, through September 2021. On March 29, 2016, we filed with the SEC a registration statement on Form S-8 to register an additional 2.5 million shares; we also listed such shares with the New York Stock Exchange. 2011 Share Repurchase Program We did not repurchase any shares during the nine months ended June 30, 2016 and 2015 under our 2011 share repurchase program, which is scheduled to end on September 30, 2016. Accumulated Other Comprehensive Income (Loss) We record deferred gains (losses) in AOCI related to available-for-sale securities, interest rate agreement cash flow hedges and commodity contract cash flow hedges. Deferred gains (losses) for our available-for-sale securities and commodity contract cash flow hedges are recognized in earnings upon settlement, while deferred gains (losses) related to our interest rate agreement cash flow hedges are recognized in earnings as they are amortized. The following tables provide the components of our accumulated other comprehensive income (loss) balances, net of the related tax effects allocated to each component of other comprehensive income (loss). Available- for-Sale Securities Interest Rate Agreement Cash Flow Hedges Commodity Contracts Cash Flow Hedges Total (In thousands) September 30, 2015 $ 4,949 $ (88,842 ) $ (25,437 ) $ (109,330 ) Other comprehensive loss before reclassifications (1,417 ) (88,345 ) (8,612 ) (98,374 ) Amounts reclassified from accumulated other comprehensive income (79 ) 260 29,290 29,471 Net current-period other comprehensive income (loss) (1,496 ) (88,085 ) 20,678 (68,903 ) June 30, 2016 $ 3,453 $ (176,927 ) $ (4,759 ) $ (178,233 ) Available- for-Sale Securities Interest Rate Agreement Cash Flow Hedges Commodity Contracts Cash Flow Hedges Total (In thousands) September 30, 2014 $ 7,662 $ (18,381 ) $ (1,674 ) $ (12,393 ) Other comprehensive income (loss) before reclassifications 30 (30,436 ) (37,397 ) (67,803 ) Amounts reclassified from accumulated other comprehensive income (326 ) 455 17,826 17,955 Net current-period other comprehensive income (loss) (296 ) (29,981 ) (19,571 ) (49,848 ) June 30, 2015 $ 7,366 $ (48,362 ) $ (21,245 ) $ (62,241 ) The following tables detail reclassifications out of AOCI for the three and nine months ended June 30, 2016 and 2015 . Amounts in parentheses below indicate decreases to net income in the statement of income. Three Months Ended June 30, 2016 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Cash flow hedges Interest rate agreements $ (137 ) Interest charges Commodity contracts (12,347 ) Purchased gas cost (12,484 ) Total before tax 4,865 Tax benefit Total reclassifications $ (7,619 ) Net of tax Three Months Ended June 30, 2015 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 508 Operation and maintenance expense 508 Total before tax (186 ) Tax expense $ 322 Net of tax Cash flow hedges Interest rate agreements $ (137 ) Interest charges Commodity contracts (16,488 ) Purchased gas cost (16,625 ) Total before tax 6,480 Tax benefit $ (10,145 ) Net of tax Total reclassifications $ (9,823 ) Net of tax Nine Months Ended June 30, 2016 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 124 Operation and maintenance expense 124 Total before tax (45 ) Tax expense $ 79 Net of tax Cash flow hedges Interest rate agreements $ (410 ) Interest charges Commodity contracts (48,015 ) Purchased gas cost (48,425 ) Total before tax 18,875 Tax benefit $ (29,550 ) Net of tax Total reclassifications $ (29,471 ) Net of tax Nine Months Ended June 30, 2015 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 514 Operation and maintenance expense 514 Total before tax (188 ) Tax expense $ 326 Net of tax Cash flow hedges Interest rate agreements $ (717 ) Interest charges Commodity contracts (29,222 ) Purchased gas cost (29,939 ) Total before tax 11,658 Tax benefit $ (18,281 ) Net of tax Total reclassifications $ (17,955 ) Net of tax

Interim Pension and Other Postr

Interim Pension and Other Postretirement Benefit Plan Information	9 Months Ended
	Jun. 30, 2016
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Interim Pension and Postretirement Benefit Plans	Interim Pension and Other Postretirement Benefit Plan Information The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three and nine months ended June 30, 2016 and 2015 are presented in the following table. Most of these costs are recoverable through our gas distribution rates; however, a portion of these costs is capitalized into our gas distribution rate base. The remaining costs are recorded as a component of operation and maintenance expense. Three Months Ended June 30 Pension Benefits Other Benefits 2016 2015 2016 2015 (In thousands) Components of net periodic pension cost: Service cost $ 4,698 $ 5,051 $ 2,705 $ 3,895 Interest cost 7,095 6,698 3,106 3,596 Expected return on assets (6,881 ) (6,435 ) (1,566 ) (1,608 ) Amortization of transition obligation — — 21 69 Amortization of prior service credit (57 ) (48 ) (411 ) (411 ) Amortization of actuarial (gain) loss 3,319 3,916 (541 ) — Net periodic pension cost $ 8,174 $ 9,182 $ 3,314 $ 5,541 Nine Months Ended June 30 Pension Benefits Other Benefits 2016 2015 2016 2015 (In thousands) Components of net periodic pension cost: Service cost $ 14,093 $ 15,153 $ 8,117 $ 11,687 Interest cost 21,284 20,095 9,318 10,789 Expected return on assets (20,642 ) (19,308 ) (4,698 ) (4,824 ) Amortization of transition obligation — — 62 205 Amortization of prior service credit (170 ) (144 ) (1,233 ) (1,233 ) Amortization of actuarial (gain) loss 9,959 11,749 (1,625 ) — Net periodic pension cost $ 24,524 $ 27,545 $ 9,941 $ 16,624 The assumptions used to develop our net periodic pension cost for the three and nine months ended June 30, 2016 and 2015 are as follows: Pension Benefits Other Benefits 2016 2015 2016 2015 Discount rate 4.55% 4.43% 4.55% 4.43% Rate of compensation increase 3.50% 3.50% N/A N/A Expected return on plan assets 7.00% 7.25% 4.45% 4.60% The discount rate used to compute the present value of a plan’s liabilities generally is based on rates of high-grade corporate bonds with maturities similar to the average period over which the benefits will be paid. Generally, our funding policy has been to contribute annually an amount in accordance with the requirements of the Employee Retirement Income Security Act of 1974. In accordance with the Pension Protection Act of 2006 (PPA), we determined the funded status of our plan as of January 1, 2016. Based on that determination, we are not required to make a minimum contribution to our defined benefit plan; however, we made a voluntary contribution of $15.0 million during the third quarter of fiscal 2016. We contributed $12.8 million to our other post-retirement benefit plans during the nine months ended June 30, 2016 . We expect to contribute between $15 million and $25 million to these plans during fiscal 2016 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation and Environmental Matters With respect to the specific litigation and environmental-related matters or claims that were disclosed in Note 10 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 , there were no material changes in the status of such litigation and environmental-related matters or claims during the nine months ended June 30, 2016 . We are a party to various litigation and environmental-related matters or claims that have arisen in the ordinary course of our business. While the results of such litigation and response actions to such environmental-related matters or claims cannot be predicted with certainty, we continue to believe the final outcome of such litigation and matters or claims will not have a material adverse effect on our financial condition, results of operations or cash flows. Purchase Commitments Our regulated distribution divisions, except for our Mid-Tex Division, maintain supply contracts with several vendors that generally cover a period of up to one year. Commitments for estimated base gas volumes are established under these contracts on a monthly basis at contractually negotiated prices. Commitments for incremental daily purchases are made as necessary during the month in accordance with the terms of the individual contract. Our Mid-Tex Division also maintains a limited number of long-term supply contracts to ensure a reliable source of gas for our customers in its service area which obligate it to purchase specified volumes at prices indexed to natural gas distribution hubs. These purchase commitment contracts are detailed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . There were no material changes to the purchase commitments for the nine months ended June 30, 2016 . AEH has commitments to purchase physical quantities of natural gas under contracts indexed to the forward NYMEX strip or fixed price contracts. These purchase commitment contracts are detailed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . Except for purchases made in the normal course of business under these contracts, there were no material changes to the purchase commitments for the nine months ended June 30, 2016 . Our nonregulated segment maintains long-term contracts related to storage and transportation. The estimated contractual demand fees for contracted storage and transportation under these contracts are detailed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . There were no material changes to the estimated storage and transportation fees for the nine months ended June 30, 2016 . Regulatory Matters Various regulatory agencies, including the SEC and the Commodities Futures Trading Commission, continue to adopt regulations implementing many of the provisions of the Dodd-Frank Act of 2010. We continue to enact new procedures and modify existing business practices and contractual arrangements to comply with such regulations. Additional rulemakings are pending which we believe will result in new reporting and disclosure obligations. The costs associated with hedging certain risks inherent in our business may be further increased when these expected additional regulations are adopted. As of June 30, 2016 , rate cases were in progress in our Kentucky and Virginia service areas, two formula rate mechanisms were in progress in our Louisiana service area and an infrastructure mechanism was in progress in our Mississippi service area. These regulatory proceedings are discussed in further detail below in Management’s Discussion and Analysis — Recent Ratemaking Developments .

Financial Instruments

Financial Instruments	9 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial Instruments We currently use financial instruments in our regulated distribution and nonregulated segments to mitigate commodity price risk and interest rate risk. The objectives and strategies for using financial instruments, which have been tailored to our regulated distribution and nonregulated segments, and the related accounting for these financial instruments are fully described in Notes 2 and 12 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . During the nine months ended June 30, 2016 there were no changes in our objectives, strategies and accounting for using financial instruments. Our financial instruments do not contain any credit-risk-related or other contingent features that could cause payments to be accelerated when our financial instruments are in net liability positions. The following summarizes those objectives and strategies. Regulated Commodity Risk Management Activities Our purchased gas cost adjustment mechanisms essentially insulate our regulated distribution segment from commodity price risk; however, our customers are exposed to the effects of volatile natural gas prices. We manage this exposure through a combination of physical storage, fixed-price forward contracts and financial instruments, primarily over-the-counter swap and option contracts, in an effort to minimize the impact of natural gas price volatility on our customers during the winter heating season. We typically seek to hedge between 25 and 50 percent of anticipated heating season gas purchases using financial instruments. For the 2015 - 2016 heating season (generally October through March), in the jurisdictions where we are permitted to utilize financial instruments, we hedged approximately 33 percent , or 23.0 Bcf of the winter flowing gas requirements. We have not designated these financial instruments as hedges for accounting purposes. Nonregulated Commodity Risk Management Activities Our nonregulated segment is exposed to risks associated with changes in the market price of natural gas through the purchase, sale and delivery of natural gas to its customers at competitive prices. We manage our exposure to such risks through a combination of physical storage and financial instruments, including futures, over-the-counter and exchange-traded options and swap contracts with counterparties. Specifically, these operations use financial instruments in the following ways: • Gas delivery and related services - Certain financial instruments, designated as cash flow hedges of anticipated purchases and sales at index prices, are used to mitigate the commodity price risk associated with deliveries under fixed-priced forward contracts to either deliver gas to customers or purchase gas from suppliers. These financial instruments have maturity dates ranging from one to 54 months . • Transportation and storage services - Our nonregulated operations use storage swaps and futures to capture additional storage arbitrage opportunities that arise subsequent to the execution of the original fair value hedge associated with our physical natural gas inventory, basis swaps to insulate and protect the economic value of our fixed price and storage books and various over-the-counter and exchange-traded options. These financial instruments have not been designated as hedges for accounting purposes. • Aggregating and purchasing gas supply - Certain financial instruments, designated as fair value hedges, are used to hedge our natural gas inventory used in asset optimization activities. Interest Rate Risk Management Activities We periodically manage interest rate risk by entering into financial instruments to effectively fix the Treasury yield component of the interest cost associated with anticipated financings. As of June 30, 2016 , we had forward starting interest rate swaps to effectively fix the Treasury yield component associated with the anticipated issuance of $250 million and $450 million unsecured senior notes in fiscal 2017 and fiscal 2019, at 3.37% and 3.78% , which we designated as cash flow hedges at the time the swaps were executed. As of June 30, 2016 , we had $18.4 million of net realized losses in accumulated other comprehensive income (AOCI) associated with the settlement of financial instruments used to fix the Treasury yield component of the interest cost of financing various issuances of long-term debt and senior notes, which will be recognized as a component of interest expense over the life of the associated notes from the date of settlement. The remaining amortization periods for these settled amounts extend through fiscal 2045. Quantitative Disclosures Related to Financial Instruments The following tables present detailed information concerning the impact of financial instruments on our condensed consolidated balance sheet and income statements. As of June 30, 2016 , our financial instruments were comprised of both long and short commodity positions. A long position is a contract to purchase the commodity, while a short position is a contract to sell the commodity. As of June 30, 2016 , we had net long/(short) commodity contracts outstanding in the following quantities: Contract Type Hedge Designation Regulated Distribution Nonregulated Quantity (MMcf) Commodity contracts Fair Value — (35,118 ) Cash Flow — 45,325 Not designated 10,002 51,128 10,002 61,335 Financial Instruments on the Balance Sheet The following tables present the fair value and balance sheet classification of our financial instruments by operating segment as of June 30, 2016 and September 30, 2015 . The gross amounts of recognized assets and liabilities are netted within our unaudited Condensed Consolidated Balance Sheets to the extent that we have netting arrangements with the counterparties. Regulated Distribution Nonregulated Balance Sheet Location Assets Liabilities Assets Liabilities (In thousands) June 30, 2016 Designated As Hedges: Commodity contracts Other current assets / Other current liabilities $ — $ — $ 10,149 $ (35,680 ) Interest rate contracts Other current assets / Other current liabilities — (65,533 ) — — Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities — — 3,911 (3,831 ) Interest rate contracts Deferred charges and other assets / Deferred credits and other liabilities — (184,131 ) — — Total — (249,664 ) 14,060 (39,511 ) Not Designated As Hedges: Commodity contracts Other current assets / Other current liabilities 3,651 (40 ) 27,247 (20,407 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities 750 — 10,812 (9,983 ) Total 4,401 (40 ) 38,059 (30,390 ) Gross Financial Instruments 4,401 (249,704 ) 52,119 (69,901 ) Gross Amounts Offset on Consolidated Balance Sheet: Contract netting — — (51,210 ) 51,210 Net Financial Instruments 4,401 (249,704 ) 909 (18,691 ) Cash collateral — 16,330 4,046 18,691 Net Assets/Liabilities from Risk Management Activities $ 4,401 $ (233,374 ) $ 4,955 $ — Regulated Distribution Nonregulated Balance Sheet Location Assets Liabilities Assets Liabilities (In thousands) September 30, 2015 Designated As Hedges: Commodity contracts Other current assets / Other current liabilities $ — $ — $ 11,680 $ (36,067 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities — — 126 (9,918 ) Interest rate contracts Deferred charges and other assets / Deferred credits and other liabilities — (110,539 ) — — Total — (110,539 ) 11,806 (45,985 ) Not Designated As Hedges: Commodity contracts Other current assets / Other current liabilities 378 (9,568 ) 65,239 (65,780 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities 368 — 14,318 (14,218 ) Total 746 (9,568 ) 79,557 (79,998 ) Gross Financial Instruments 746 (120,107 ) 91,363 (125,983 ) Gross Amounts Offset on Consolidated Balance Sheet: Contract netting — — (91,363 ) 91,363 Net Financial Instruments 746 (120,107 ) — (34,620 ) Cash collateral — — 8,854 34,620 Net Assets/Liabilities from Risk Management Activities $ 746 $ (120,107 ) $ 8,854 $ — Impact of Financial Instruments on the Income Statement Hedge ineffectiveness for our nonregulated segment is recorded as a component of purchased gas cost and primarily results from differences in the location and timing of the derivative instrument and the hedged item. Hedge ineffectiveness could materially affect our results of operations for the reported period. For the three months ended June 30, 2016 and 2015 we recognized gains arising from fair value and cash flow hedge ineffectiveness of $13.6 million and $3.6 million . For the nine months ended June 30, 2016 and 2015 we recognized a gain (loss) arising from fair value and cash flow hedge ineffectiveness of $18.1 million and $(0.9) million . Additional information regarding ineffectiveness recognized in the income statement is included in the tables below. Fair Value Hedges The impact of our nonregulated commodity contracts designated as fair value hedges and the related hedged item on our condensed consolidated income statement for the three and nine months ended June 30, 2016 and 2015 is presented below. Three Months Ended 2016 2015 (In thousands) Commodity contracts $ (22,146 ) $ (1,715 ) Fair value adjustment for natural gas inventory designated as the hedged item 35,630 5,350 Total decrease in purchased gas cost $ 13,484 $ 3,635 The decrease in purchased gas cost is comprised of the following: Basis ineffectiveness $ (684 ) $ 599 Timing ineffectiveness 14,168 3,036 $ 13,484 $ 3,635 Nine Months Ended 2016 2015 (In thousands) Commodity contracts $ (11,808 ) $ 5,754 Fair value adjustment for natural gas inventory designated as the hedged item 29,852 (6,291 ) Total (increase) decrease in purchased gas cost $ 18,044 $ (537 ) The (increase) decrease in purchased gas cost is comprised of the following: Basis ineffectiveness $ (1,490 ) $ 908 Timing ineffectiveness 19,534 (1,445 ) $ 18,044 $ (537 ) Basis ineffectiveness arises from natural gas market price differences between the locations of the hedged inventory and the delivery location specified in the hedge instruments. Timing ineffectiveness arises due to changes in the difference between the spot price and the futures price, as well as the difference between the timing of the settlement of the futures and the valuation of the underlying physical commodity. As the commodity contract nears the settlement date, spot-to-forward price differences should converge, which should reduce or eliminate the impact of this ineffectiveness on purchased gas cost. To the extent that the Company’s natural gas inventory does not qualify as a hedged item in a fair-value hedge, or has not been designated as such, the natural gas inventory is valued at the lower of cost or market. Cash Flow Hedges The impact of cash flow hedges on our condensed consolidated income statements for the three and nine months ended June 30, 2016 and 2015 is presented below. Note that this presentation does not reflect the financial impact arising from the hedged physical transaction. Therefore, this presentation is not indicative of the economic gross profit we realized when the underlying physical and financial transactions were settled. Three Months Ended June 30, 2016 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (12,347 ) $ (12,347 ) Gain arising from ineffective portion of commodity contracts — 66 66 Total impact on purchased gas cost — (12,281 ) (12,281 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (137 ) — (137 ) Total Impact from Cash Flow Hedges $ (137 ) $ (12,281 ) $ (12,418 ) Three Months Ended June 30, 2015 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (16,488 ) $ (16,488 ) Gain arising from ineffective portion of commodity contracts — 11 11 Total impact on purchased gas cost — (16,477 ) (16,477 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (137 ) — (137 ) Total Impact from Cash Flow Hedges $ (137 ) $ (16,477 ) $ (16,614 ) Nine Months Ended June 30, 2016 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (48,015 ) $ (48,015 ) Gain arising from ineffective portion of commodity contracts — 84 84 Total impact on purchased gas cost — (47,931 ) (47,931 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (410 ) — (410 ) Total Impact from Cash Flow Hedges $ (410 ) $ (47,931 ) $ (48,341 ) Nine Months Ended June 30, 2015 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (29,222 ) $ (29,222 ) Loss arising from ineffective portion of commodity contracts — (316 ) (316 ) Total impact on purchased gas cost — (29,538 ) (29,538 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (717 ) — (717 ) Total Impact from Cash Flow Hedges $ (717 ) $ (29,538 ) $ (30,255 ) The following table summarizes the gains and losses arising from hedging transactions that were recognized as a component of other comprehensive income (loss), net of taxes, for the three and nine months ended June 30, 2016 and 2015 . The amounts included in the table below exclude gains and losses arising from ineffectiveness because those amounts are immediately recognized in the income statement as incurred. Three Months Ended Nine Months Ended 2016 2015 2016 2015 (In thousands) Increase (decrease) in fair value: Interest rate agreements $ (39,337 ) $ 54,388 $ (88,345 ) $ (30,436 ) Forward commodity contracts 10,573 1,505 (8,612 ) (37,397 ) Recognition of (gains) losses in earnings due to settlements: Interest rate agreements 87 87 260 455 Forward commodity contracts 7,532 10,058 29,290 17,826 Total other comprehensive income (loss) from hedging, net of tax (1) $ (21,145 ) $ 66,038 $ (67,407 ) $ (49,552 ) (1) Utilizing an income tax rate ranging from 37 percent to 39 percent based on the effective rates in each taxing jurisdiction. Deferred gains (losses) recorded in AOCI associated with our interest rate agreements are recognized in earnings as they are amortized over the terms of the underlying debt instruments, while deferred gains (losses) associated with commodity contracts are recognized in earnings upon settlement. The following amounts, net of deferred taxes, represent the expected recognition in earnings of the deferred losses recorded in AOCI associated with our financial instruments, based upon the fair values of these financial instruments as of June 30, 2016 . However, the table below does not include the expected recognition in earnings of our outstanding interest rate agreements as those instruments have not yet settled. Interest Rate Agreements Commodity Contracts Total (In thousands) Next twelve months $ (372 ) $ (4,992 ) $ (5,364 ) Thereafter (18,018 ) 233 (17,785 ) Total (1) $ (18,390 ) $ (4,759 ) $ (23,149 ) (1) Utilizing an income tax rate ranging from 37 percent to 39 percent based on the effective rates in each taxing jurisdiction. Financial Instruments Not Designated as Hedges The impact of financial instruments that have not been designated as hedges on our condensed consolidated income statements for the three months ended June 30, 2016 and 2015 was a decrease in purchased gas cost of $1.9 million and $3.7 million . For the nine months ended June 30, 2016 and 2015 purchased gas cost (increased) decreased by $(2.8) million and $13.2 million . Note that this presentation does not reflect the expected gains or losses arising from the underlying physical transactions associated with these financial instruments. Therefore, this presentation is not indicative of the economic gross profit we realized when the underlying physical and financial transactions were settled. As discussed above, financial instruments used in our regulated distribution segment are not designated as hedges. However, there is no earnings impact on our regulated distribution segment as a result of the use of these financial instruments because the gains and losses arising from the use of these financial instruments are recognized in the consolidated statement of income as a component of purchased gas cost when the related costs are recovered through our rates and recognized in revenue. Accordingly, the impact of these financial instruments is excluded from this presentation.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We record cash and cash equivalents, accounts receivable and accounts payable at carrying value, which substantially approximates fair value due to the short-term nature of these assets and liabilities. For other financial assets and liabilities, we primarily use quoted market prices and other observable market pricing information to minimize the use of unobservable pricing inputs in our measurements when determining fair value. The methods used to determine fair value for our assets and liabilities are fully described in Note 2 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . During the nine months ended June 30, 2016 , there were no changes in these methods. Fair value measurements also apply to the valuation of our pension and postretirement plan assets. Current accounting guidance requires employers to annually disclose information about fair value measurements of the assets of a defined benefit pension or other postretirement plan. The fair value of these assets is presented in Note 6 to the financial statements in our Annual Report on Form 10-K for the fiscal year ending September 30, 2015 . Quantitative Disclosures Financial Instruments The classification of our fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. Authoritative accounting literature establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1), with the lowest priority given to unobservable inputs (Level 3). The following tables summarize, by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of June 30, 2016 and September 30, 2015 . Assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) (1) Significant Other Unobservable Inputs (Level 3) Netting and Cash Collateral (2) June 30, 2016 (In thousands) Assets: Financial instruments Regulated distribution segment $ — $ 4,401 $ — $ — $ 4,401 Nonregulated segment — 52,119 — (47,164 ) 4,955 Total financial instruments — 56,520 — (47,164 ) 9,356 Hedged portion of gas stored underground 97,860 — — — 97,860 Available-for-sale securities Money market funds — 1,358 — — 1,358 Registered investment companies 39,068 — — — 39,068 Bonds — 31,319 — — 31,319 Total available-for-sale securities 39,068 32,677 — — 71,745 Total assets $ 136,928 $ 89,197 $ — $ (47,164 ) $ 178,961 Liabilities: Financial instruments Regulated distribution segment $ — $ 249,704 $ — $ (16,330 ) $ 233,374 Nonregulated segment — 69,901 — (69,901 ) — Total liabilities $ — $ 319,605 $ — $ (86,231 ) $ 233,374 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) (1) Significant Other Unobservable Inputs (Level 3) Netting and Cash Collateral (3) September 30, 2015 (In thousands) Assets: Financial instruments Regulated distribution segment $ — $ 746 $ — $ — $ 746 Nonregulated segment — 91,363 — (82,509 ) 8,854 Total financial instruments — 92,109 — (82,509 ) 9,600 Hedged portion of gas stored underground 43,901 — — — 43,901 Available-for-sale securities Money market funds — 1,072 — — 1,072 Registered investment companies 40,619 — — — 40,619 Bonds — 32,509 — — 32,509 Total available-for-sale securities 40,619 33,581 — — 74,200 Total assets $ 84,520 $ 125,690 $ — $ (82,509 ) $ 127,701 Liabilities: Financial instruments Regulated distribution segment $ — $ 120,107 $ — $ — $ 120,107 Nonregulated segment — 125,983 — (125,983 ) — Total liabilities $ — $ 246,090 $ — $ (125,983 ) $ 120,107 (1) Our Level 2 measurements consist of over-the-counter options and swaps which are valued using a market-based approach in which observable market prices are adjusted for criteria specific to each instrument, such as the strike price, notional amount or basis differences, municipal and corporate bonds which are valued based on the most recent available quoted market prices and money market funds which are valued at cost. (2) This column reflects adjustments to our gross financial instrument assets and liabilities to reflect netting permitted under our master netting agreements and the relevant authoritative accounting literature. In addition, as of June 30, 2016 , we had $16.3 million of cash held in margin accounts to collateralize certain regulated distribution financial instruments, which were used to offset current and noncurrent risk management liabilities. As of June 30, 2016 , we also had $22.7 million of cash held in margin accounts to collateralize certain nonregulated financial instruments. Of this amount, $18.7 million was used to offset current and noncurrent risk management liabilities under master netting arrangements with the remaining $4.0 million classified as current risk management assets. (3) This column reflects adjustments to our gross financial instrument assets and liabilities to reflect netting permitted under our master netting agreements and the relevant authoritative accounting literature. In addition, as of September 30, 2015 , we had $43.5 million of cash held in margin accounts to collateralize certain nonregulated financial instruments. Of this amount, $34.6 million was used to offset current and noncurrent risk management liabilities under master netting arrangements with the remaining $8.9 million is classified as current risk management assets. Available-for-sale securities are comprised of the following: Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value (In thousands) As of June 30, 2016 Domestic equity mutual funds $ 28,377 $ 5,549 $ (962 ) $ 32,964 Foreign equity mutual funds 5,357 747 — 6,104 Bonds 31,147 175 (3 ) 31,319 Money market funds 1,358 — — 1,358 $ 66,239 $ 6,471 $ (965 ) $ 71,745 As of September 30, 2015 Domestic equity mutual funds $ 27,643 $ 7,332 $ (456 ) $ 34,519 Foreign equity mutual funds 5,261 905 (66 ) 6,100 Bonds 32,423 106 (20 ) 32,509 Money market funds 1,072 — — 1,072 $ 66,399 $ 8,343 $ (542 ) $ 74,200 At June 30, 2016 and September 30, 2015 , our available-for-sale securities included $40.4 million and $41.7 million related to assets held in separate rabbi trusts for our supplemental executive benefit plans. At June 30, 2016 , we maintained investments in bonds that have contractual maturity dates ranging from July 2016 through September 2020. These securities are reported at market value with unrealized gains and losses shown as a component of accumulated other comprehensive income (loss). We regularly evaluate the performance of these investments on a fund by fund basis for impairment, taking into consideration the fund’s purpose, volatility and current returns. If a determination is made that a decline in fair value is other than temporary, the related fund is written down to its estimated fair value and the other-than-temporary impairment is recognized in the income statement. Other Fair Value Measures Our debt is recorded at carrying value. The fair value of our debt is determined using third party market value quotations, which are considered Level 1 fair value measurements for debt instruments with a recent, observable trade or Level 2 fair value measurements for debt instruments where fair value is determined using the most recent available quoted market price. The following table presents the carrying value and fair value of our debt as of June 30, 2016 and September 30, 2015 : June 30, 2016 September 30, 2015 (In thousands) Carrying Amount $ 2,460,000 $ 2,460,000 Fair Value $ 2,858,540 $ 2,669,323

Concentration of Credit Risk

Concentration of Credit Risk	9 Months Ended
	Jun. 30, 2016
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk Information regarding our concentration of credit risk is disclosed in Note 15 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . During the nine months ended June 30, 2016 , there were no material changes in our concentration of credit risk.

Accounting Policies (Policy)

Accounting Policies (Policy)	9 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Regulatory assets and liabilities	Regulatory assets and liabilities Accounting principles generally accepted in the United States require cost-based, rate-regulated entities that meet certain criteria to reflect the authorized recovery of costs due to regulatory decisions in their financial statements. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. We record certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. Substantially all of our regulatory assets are recorded as a component of deferred charges and other assets and substantially all of our regulatory liabilities are recorded as a component of deferred credits and other liabilities. Deferred gas costs are recorded either in other current assets or liabilities and the regulatory cost of removal obligation is reported separately.
Segment Reporting	Segment Information We operate the Company through the following three segments: • The regulated distribution segment , which includes our regulated natural gas distribution and related sales operations, • The regulated pipeline segment , which includes the regulated pipeline and storage operations of our Atmos Pipeline — Texas Division and • The nonregulated segment , which is comprised of our nonregulated natural gas management, nonregulated natural gas transmission, storage and other services. Our determination of reportable segments considers the strategic operating units under which we manage sales of various products and services to customers in differing regulatory environments. Although our regulated distribution segment operations are geographically dispersed, they are reported as a single segment as each regulated distribution division has similar economic characteristics. The accounting policies of the segments are the same as those described in the summary of significant accounting policies found in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . We evaluate performance based on net income or loss of the respective operating units.
Earnings Per Share	Earnings Per Share We use the two-class method of computing earnings per share because we have participating securities in the form of non-vested restricted stock units with a nonforfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator.
Fair Value Measurements	Fair Value Measurements We report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We record cash and cash equivalents, accounts receivable and accounts payable at carrying value, which substantially approximates fair value due to the short-term nature of these assets and liabilities. For other financial assets and liabilities, we primarily use quoted market prices and other observable market pricing information to minimize the use of unobservable pricing inputs in our measurements when determining fair value. The methods used to determine fair value for our assets and liabilities are fully described in Note 2 to the financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2015 . During the nine months ended June 30, 2016 , there were no changes in these methods.

Unaudited Financial Informati20

Unaudited Financial Information (Table)	9 Months Ended
	Jun. 30, 2016
Regulatory Assets And Liabilities Table [Abstract]
Schedule of Regulatory Assets [Table Text Block]	Significant regulatory assets and liabilities as of June 30, 2016 and September 30, 2015 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs (1) $ 110,425 $ 121,183 Infrastructure mechanisms (2) 31,090 32,813 Deferred gas costs 3,390 9,715 Recoverable loss on reacquired debt 14,401 16,319 APT annual adjustment mechanism 2,976 1,002 Rate case costs 1,640 1,533 Other 20,906 9,774 $ 184,828 $ 192,339 Regulatory liabilities: Regulatory cost of removal obligations $ 486,290 $ 483,676 Deferred gas costs 34,362 28,100 Asset retirement obligations 9,063 9,063 Other 5,483 3,693 $ 535,198 $ 524,532 (1) Includes $12.9 million and $16.6 million of pension and postretirement expense deferred pursuant to regulatory authorization. (2) Infrastructure mechanisms in Texas and Louisiana allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consist of interest, depreciation and other taxes, until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates.
Schedule of Regulatory Liabilities [Table Text Block]	Significant regulatory assets and liabilities as of June 30, 2016 and September 30, 2015 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs (1) $ 110,425 $ 121,183 Infrastructure mechanisms (2) 31,090 32,813 Deferred gas costs 3,390 9,715 Recoverable loss on reacquired debt 14,401 16,319 APT annual adjustment mechanism 2,976 1,002 Rate case costs 1,640 1,533 Other 20,906 9,774 $ 184,828 $ 192,339 Regulatory liabilities: Regulatory cost of removal obligations $ 486,290 $ 483,676 Deferred gas costs 34,362 28,100 Asset retirement obligations 9,063 9,063 Other 5,483 3,693 $ 535,198 $ 524,532 (1) Includes $12.9 million and $16.6 million of pension and postretirement expense deferred pursuant to regulatory authorization. (2) Infrastructure mechanisms in Texas and Louisiana allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consist of interest, depreciation and other taxes, until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates.

Segment Information (Table)

Segment Information (Table)	9 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Income statements for the three and nine months ended June 30, 2016 and 2015 by segment are presented in the following tables: Three Months Ended June 30, 2016 Regulated Distribution Regulated Pipeline Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 411,982 $ 28,518 $ 192,416 $ — $ 632,916 Intersegment revenues 2,244 80,731 22,139 (105,114 ) — 414,226 109,249 214,555 (105,114 ) 632,916 Purchased gas cost 138,845 — 191,741 (104,981 ) 225,605 Gross profit 275,381 109,249 22,814 (133 ) 407,311 Operating expenses Operation and maintenance 100,859 29,083 7,635 (133 ) 137,444 Depreciation and amortization 58,916 13,409 1,134 — 73,459 Taxes, other than income 52,377 6,220 647 — 59,244 Total operating expenses 212,152 48,712 9,416 (133 ) 270,147 Operating income 63,229 60,537 13,398 — 137,164 Miscellaneous income (expense) 1,111 (359 ) 574 (493 ) 833 Interest charges 18,968 9,002 221 (493 ) 27,698 Income before income taxes 45,372 51,176 13,751 — 110,299 Income tax expense 15,516 18,046 5,544 — 39,106 Net income $ 29,856 $ 33,130 $ 8,207 $ — $ 71,193 Capital expenditures $ 191,202 $ 66,639 $ (66 ) $ — $ 257,775 Three Months Ended June 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 415,160 $ 25,859 $ 245,382 $ — $ 686,401 Intersegment revenues 1,634 71,149 33,387 (106,170 ) — 416,794 97,008 278,769 (106,170 ) 686,401 Purchased gas cost 149,775 — 260,990 (106,037 ) 304,728 Gross profit 267,019 97,008 17,779 (133 ) 381,673 Operating expenses Operation and maintenance 98,552 26,572 7,456 (133 ) 132,447 Depreciation and amortization 55,491 11,816 1,137 — 68,444 Taxes, other than income 56,176 6,193 806 — 63,175 Total operating expenses 210,219 44,581 9,399 (133 ) 264,066 Operating income 56,800 52,427 8,380 — 117,607 Miscellaneous income (expense) 1,045 (211 ) 345 (545 ) 634 Interest charges 19,961 8,299 240 (545 ) 27,955 Income before income taxes 37,884 43,917 8,485 — 90,286 Income tax expense 15,420 15,349 3,236 — 34,005 Net income $ 22,464 $ 28,568 $ 5,249 $ — $ 56,281 Capital expenditures $ 170,134 $ 55,914 $ (209 ) $ — $ 225,839 Nine Months Ended June 30, 2016 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 1,896,636 $ 75,344 $ 699,450 $ — $ 2,671,430 Intersegment revenues 5,877 224,285 75,024 (305,186 ) — 1,902,513 299,629 774,474 (305,186 ) 2,671,430 Purchased gas cost 884,529 — 722,803 (304,787 ) 1,302,545 Gross profit 1,017,984 299,629 51,671 (399 ) 1,368,885 Operating expenses Operation and maintenance 291,388 83,302 21,667 (399 ) 395,958 Depreciation and amortization 173,913 39,358 3,399 — 216,670 Taxes, other than income 152,324 18,529 2,019 — 172,872 Total operating expenses 617,625 141,189 27,085 (399 ) 785,500 Operating income 400,359 158,440 24,586 — 583,385 Miscellaneous income (expense) 209 (1,164 ) 1,245 (1,351 ) (1,061 ) Interest charges 58,390 27,294 1,408 (1,351 ) 85,741 Income before income taxes 342,178 129,982 24,423 — 496,583 Income tax expense 124,755 46,081 9,883 — 180,719 Net income $ 217,423 $ 83,901 $ 14,540 $ — $ 315,864 Capital expenditures $ 533,826 $ 262,058 $ 124 $ — $ 796,008 Nine Months Ended June 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) Operating revenues from external parties $ 2,389,037 $ 70,887 $ 1,025,310 $ — $ 3,485,234 Intersegment revenues 5,142 201,418 154,069 (360,629 ) — 2,394,179 272,305 1,179,379 (360,629 ) 3,485,234 Purchased gas cost 1,397,113 — 1,122,655 (360,230 ) 2,159,538 Gross profit 997,066 272,305 56,724 (399 ) 1,325,696 Operating expenses Operation and maintenance 288,962 74,029 21,897 (399 ) 384,489 Depreciation and amortization 165,730 34,945 3,384 — 204,059 Taxes, other than income 162,759 16,296 2,551 — 181,606 Total operating expenses 617,451 125,270 27,832 (399 ) 770,154 Operating income 379,615 147,035 28,892 — 555,542 Miscellaneous income (expense) (1,221 ) (842 ) 897 (1,468 ) (2,634 ) Interest charges 60,914 25,014 706 (1,468 ) 85,166 Income before income taxes 317,480 121,179 29,083 — 467,742 Income tax expense 121,776 42,894 11,512 — 176,182 Net income $ 195,704 $ 78,285 $ 17,571 $ — $ 291,560 Capital expenditures $ 482,371 $ 185,028 $ 84 $ — $ 667,483 Balance sheet information at June 30, 2016 and September 30, 2015 by segment is presented in the following tables: June 30, 2016 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) ASSETS Property, plant and equipment, net $ 6,067,548 $ 1,935,087 $ 50,912 $ — $ 8,053,547 Investment in subsidiaries 1,007,787 — — (1,007,787 ) — Current assets Cash and cash equivalents 61,441 — 4,765 — 66,206 Assets from risk management activities 3,651 — 4,047 — 7,698 Other current assets 370,444 22,269 391,265 (208,969 ) 575,009 Intercompany receivables 981,651 — — (981,651 ) — Total current assets 1,417,187 22,269 400,077 (1,190,620 ) 648,913 Goodwill 575,449 132,542 34,711 — 742,702 Noncurrent assets from risk management activities 750 — 908 — 1,658 Deferred charges and other assets 258,370 21,976 202 — 280,548 $ 9,327,091 $ 2,111,874 $ 486,810 $ (2,198,407 ) $ 9,727,368 CAPITALIZATION AND LIABILITIES Shareholders’ equity $ 3,466,724 $ 661,175 $ 346,612 $ (1,007,787 ) $ 3,466,724 Long-term debt 2,205,645 — — — 2,205,645 Total capitalization 5,672,369 661,175 346,612 (1,007,787 ) 5,672,369 Current liabilities Current maturities of long-term debt 250,000 — — — 250,000 Short-term debt 870,466 — — (200,000 ) 670,466 Liabilities from risk management activities 56,883 — — — 56,883 Other current liabilities 453,831 16,590 90,999 (8,969 ) 552,451 Intercompany payables — 953,683 27,968 (981,651 ) — Total current liabilities 1,631,180 970,273 118,967 (1,190,620 ) 1,529,800 Deferred income taxes 1,093,755 480,336 11,409 — 1,585,500 Noncurrent liabilities from risk management activities 176,491 — — — 176,491 Regulatory cost of removal obligation 427,332 — — — 427,332 Pension and postretirement liabilities 283,579 — — — 283,579 Deferred credits and other liabilities 42,385 90 9,822 — 52,297 $ 9,327,091 $ 2,111,874 $ 486,810 $ (2,198,407 ) $ 9,727,368 September 30, 2015 Regulated Regulated Nonregulated Eliminations Consolidated (In thousands) ASSETS Property, plant and equipment, net $ 5,670,306 $ 1,706,449 $ 53,825 $ — $ 7,430,580 Investment in subsidiaries 1,038,670 — (2,096 ) (1,036,574 ) — Current assets Cash and cash equivalents 23,863 — 4,790 — 28,653 Assets from risk management activities 378 — 8,854 — 9,232 Other current assets 421,591 24,628 480,503 (338,301 ) 588,421 Intercompany receivables 887,713 — — (887,713 ) — Total current assets 1,333,545 24,628 494,147 (1,226,014 ) 626,306 Goodwill 575,449 132,542 34,711 — 742,702 Noncurrent assets from risk management activities 368 — — — 368 Deferred charges and other assets 270,372 17,288 5,329 — 292,989 $ 8,888,710 $ 1,880,907 $ 585,916 $ (2,262,588 ) $ 9,092,945 CAPITALIZATION AND LIABILITIES Shareholders’ equity $ 3,194,797 $ 577,275 $ 461,395 $ (1,038,670 ) $ 3,194,797 Long-term debt 2,455,388 — — — 2,455,388 Total capitalization 5,650,185 577,275 461,395 (1,038,670 ) 5,650,185 Current liabilities Short-term debt 782,927 — — (325,000 ) 457,927 Liabilities from risk management activities 9,568 — — — 9,568 Other current liabilities 569,273 29,780 99,480 (11,205 ) 687,328 Intercompany payables — 867,409 20,304 (887,713 ) — Total current liabilities 1,361,768 897,189 119,784 (1,223,918 ) 1,154,823 Deferred income taxes 1,008,091 406,254 (3,030 ) — 1,411,315 Noncurrent liabilities from risk management activities 110,539 — — — 110,539 Regulatory cost of removal obligation 427,553 — — — 427,553 Pension and postretirement liabilities 287,373 — — — 287,373 Deferred credits and other liabilities 43,201 189 7,767 — 51,157 $ 8,888,710 $ 1,880,907 $ 585,916 $ (2,262,588 ) $ 9,092,945

Earnings Per Share (Table)

Earnings Per Share (Table)	9 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Earnings per share table	Basic and diluted earnings per share for the three and nine months ended June 30, 2016 and 2015 are calculated as follows: Three Months Ended Nine Months Ended 2016 2015 2016 2015 (In thousands, except per share amounts) Basic and Diluted Earnings Per Share Net income $ 71,193 $ 56,281 $ 315,864 $ 291,560 Less: Income allocated to participating securities 108 111 496 596 Income available to common shareholders $ 71,085 $ 56,170 $ 315,368 $ 290,964 Basic and diluted weighted average shares outstanding 103,750 102,000 103,137 101,776 Net income per share - Basic and Diluted $ 0.69 $ 0.55 $ 3.06 $ 2.86

Debt (Table)

Debt (Table)	9 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Components of Debt	Long-term debt at June 30, 2016 and September 30, 2015 consisted of the following: June 30, 2016 September 30, 2015 (In thousands) Unsecured 6.35% Senior Notes, due June 2017 $ 250,000 $ 250,000 Unsecured 8.50% Senior Notes, due 2019 450,000 450,000 Unsecured 5.95% Senior Notes, due 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due 2044 500,000 500,000 Medium-term note Series A, 1995-1, 6.67%, due 2025 10,000 10,000 Unsecured 6.75% Debentures, due 2028 150,000 150,000 Total long-term debt 2,460,000 2,460,000 Less: Original issue discount on unsecured senior notes and debentures 4,355 4,612 Current maturities 250,000 — $ 2,205,645 $ 2,455,388

Shareholders' Equity (Table)

Shareholders' Equity (Table)	9 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables provide the components of our accumulated other comprehensive income (loss) balances, net of the related tax effects allocated to each component of other comprehensive income (loss). Available- for-Sale Securities Interest Rate Agreement Cash Flow Hedges Commodity Contracts Cash Flow Hedges Total (In thousands) September 30, 2015 $ 4,949 $ (88,842 ) $ (25,437 ) $ (109,330 ) Other comprehensive loss before reclassifications (1,417 ) (88,345 ) (8,612 ) (98,374 ) Amounts reclassified from accumulated other comprehensive income (79 ) 260 29,290 29,471 Net current-period other comprehensive income (loss) (1,496 ) (88,085 ) 20,678 (68,903 ) June 30, 2016 $ 3,453 $ (176,927 ) $ (4,759 ) $ (178,233 ) Available- for-Sale Securities Interest Rate Agreement Cash Flow Hedges Commodity Contracts Cash Flow Hedges Total (In thousands) September 30, 2014 $ 7,662 $ (18,381 ) $ (1,674 ) $ (12,393 ) Other comprehensive income (loss) before reclassifications 30 (30,436 ) (37,397 ) (67,803 ) Amounts reclassified from accumulated other comprehensive income (326 ) 455 17,826 17,955 Net current-period other comprehensive income (loss) (296 ) (29,981 ) (19,571 ) (49,848 ) June 30, 2015 $ 7,366 $ (48,362 ) $ (21,245 ) $ (62,241 )
Reclassification out of Accumulated Other Comprehensive Income	The following tables detail reclassifications out of AOCI for the three and nine months ended June 30, 2016 and 2015 . Amounts in parentheses below indicate decreases to net income in the statement of income. Three Months Ended June 30, 2016 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Cash flow hedges Interest rate agreements $ (137 ) Interest charges Commodity contracts (12,347 ) Purchased gas cost (12,484 ) Total before tax 4,865 Tax benefit Total reclassifications $ (7,619 ) Net of tax Three Months Ended June 30, 2015 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 508 Operation and maintenance expense 508 Total before tax (186 ) Tax expense $ 322 Net of tax Cash flow hedges Interest rate agreements $ (137 ) Interest charges Commodity contracts (16,488 ) Purchased gas cost (16,625 ) Total before tax 6,480 Tax benefit $ (10,145 ) Net of tax Total reclassifications $ (9,823 ) Net of tax Nine Months Ended June 30, 2016 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 124 Operation and maintenance expense 124 Total before tax (45 ) Tax expense $ 79 Net of tax Cash flow hedges Interest rate agreements $ (410 ) Interest charges Commodity contracts (48,015 ) Purchased gas cost (48,425 ) Total before tax 18,875 Tax benefit $ (29,550 ) Net of tax Total reclassifications $ (29,471 ) Net of tax Nine Months Ended June 30, 2015 Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Statement of Income (In thousands) Available-for-sale securities $ 514 Operation and maintenance expense 514 Total before tax (188 ) Tax expense $ 326 Net of tax Cash flow hedges Interest rate agreements $ (717 ) Interest charges Commodity contracts (29,222 ) Purchased gas cost (29,939 ) Total before tax 11,658 Tax benefit $ (18,281 ) Net of tax Total reclassifications $ (17,955 ) Net of tax

Interim Pension and Other Pos25

Interim Pension and Other Postretirement Benefits (Table)	9 Months Ended
	Jun. 30, 2016
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Components of net periodic pension cost table	The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three and nine months ended June 30, 2016 and 2015 are presented in the following table. Most of these costs are recoverable through our gas distribution rates; however, a portion of these costs is capitalized into our gas distribution rate base. The remaining costs are recorded as a component of operation and maintenance expense. Three Months Ended June 30 Pension Benefits Other Benefits 2016 2015 2016 2015 (In thousands) Components of net periodic pension cost: Service cost $ 4,698 $ 5,051 $ 2,705 $ 3,895 Interest cost 7,095 6,698 3,106 3,596 Expected return on assets (6,881 ) (6,435 ) (1,566 ) (1,608 ) Amortization of transition obligation — — 21 69 Amortization of prior service credit (57 ) (48 ) (411 ) (411 ) Amortization of actuarial (gain) loss 3,319 3,916 (541 ) — Net periodic pension cost $ 8,174 $ 9,182 $ 3,314 $ 5,541 Nine Months Ended June 30 Pension Benefits Other Benefits 2016 2015 2016 2015 (In thousands) Components of net periodic pension cost: Service cost $ 14,093 $ 15,153 $ 8,117 $ 11,687 Interest cost 21,284 20,095 9,318 10,789 Expected return on assets (20,642 ) (19,308 ) (4,698 ) (4,824 ) Amortization of transition obligation — — 62 205 Amortization of prior service credit (170 ) (144 ) (1,233 ) (1,233 ) Amortization of actuarial (gain) loss 9,959 11,749 (1,625 ) — Net periodic pension cost $ 24,524 $ 27,545 $ 9,941 $ 16,624
Schedule of assumptions used table text block	The assumptions used to develop our net periodic pension cost for the three and nine months ended June 30, 2016 and 2015 are as follows: Pension Benefits Other Benefits 2016 2015 2016 2015 Discount rate 4.55% 4.43% 4.55% 4.43% Rate of compensation increase 3.50% 3.50% N/A N/A Expected return on plan assets 7.00% 7.25% 4.45% 4.60%

Financial Instruments (Table)

Financial Instruments (Table)	9 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Oustanding commodity contracts volumes table	As of June 30, 2016 , we had net long/(short) commodity contracts outstanding in the following quantities: Contract Type Hedge Designation Regulated Distribution Nonregulated Quantity (MMcf) Commodity contracts Fair Value — (35,118 ) Cash Flow — 45,325 Not designated 10,002 51,128 10,002 61,335
Financial instruments on the balance sheet	Regulated Distribution Nonregulated Balance Sheet Location Assets Liabilities Assets Liabilities (In thousands) September 30, 2015 Designated As Hedges: Commodity contracts Other current assets / Other current liabilities $ — $ — $ 11,680 $ (36,067 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities — — 126 (9,918 ) Interest rate contracts Deferred charges and other assets / Deferred credits and other liabilities — (110,539 ) — — Total — (110,539 ) 11,806 (45,985 ) Not Designated As Hedges: Commodity contracts Other current assets / Other current liabilities 378 (9,568 ) 65,239 (65,780 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities 368 — 14,318 (14,218 ) Total 746 (9,568 ) 79,557 (79,998 ) Gross Financial Instruments 746 (120,107 ) 91,363 (125,983 ) Gross Amounts Offset on Consolidated Balance Sheet: Contract netting — — (91,363 ) 91,363 Net Financial Instruments 746 (120,107 ) — (34,620 ) Cash collateral — — 8,854 34,620 Net Assets/Liabilities from Risk Management Activities $ 746 $ (120,107 ) $ 8,854 $ — The following tables present the fair value and balance sheet classification of our financial instruments by operating segment as of June 30, 2016 and September 30, 2015 . The gross amounts of recognized assets and liabilities are netted within our unaudited Condensed Consolidated Balance Sheets to the extent that we have netting arrangements with the counterparties. Regulated Distribution Nonregulated Balance Sheet Location Assets Liabilities Assets Liabilities (In thousands) June 30, 2016 Designated As Hedges: Commodity contracts Other current assets / Other current liabilities $ — $ — $ 10,149 $ (35,680 ) Interest rate contracts Other current assets / Other current liabilities — (65,533 ) — — Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities — — 3,911 (3,831 ) Interest rate contracts Deferred charges and other assets / Deferred credits and other liabilities — (184,131 ) — — Total — (249,664 ) 14,060 (39,511 ) Not Designated As Hedges: Commodity contracts Other current assets / Other current liabilities 3,651 (40 ) 27,247 (20,407 ) Commodity contracts Deferred charges and other assets / Deferred credits and other liabilities 750 — 10,812 (9,983 ) Total 4,401 (40 ) 38,059 (30,390 ) Gross Financial Instruments 4,401 (249,704 ) 52,119 (69,901 ) Gross Amounts Offset on Consolidated Balance Sheet: Contract netting — — (51,210 ) 51,210 Net Financial Instruments 4,401 (249,704 ) 909 (18,691 ) Cash collateral — 16,330 4,046 18,691 Net Assets/Liabilities from Risk Management Activities $ 4,401 $ (233,374 ) $ 4,955 $ —
Fair value hedges table	The impact of our nonregulated commodity contracts designated as fair value hedges and the related hedged item on our condensed consolidated income statement for the three and nine months ended June 30, 2016 and 2015 is presented below. Three Months Ended 2016 2015 (In thousands) Commodity contracts $ (22,146 ) $ (1,715 ) Fair value adjustment for natural gas inventory designated as the hedged item 35,630 5,350 Total decrease in purchased gas cost $ 13,484 $ 3,635 The decrease in purchased gas cost is comprised of the following: Basis ineffectiveness $ (684 ) $ 599 Timing ineffectiveness 14,168 3,036 $ 13,484 $ 3,635 Nine Months Ended 2016 2015 (In thousands) Commodity contracts $ (11,808 ) $ 5,754 Fair value adjustment for natural gas inventory designated as the hedged item 29,852 (6,291 ) Total (increase) decrease in purchased gas cost $ 18,044 $ (537 ) The (increase) decrease in purchased gas cost is comprised of the following: Basis ineffectiveness $ (1,490 ) $ 908 Timing ineffectiveness 19,534 (1,445 ) $ 18,044 $ (537 )
Cash flow hedges	The impact of cash flow hedges on our condensed consolidated income statements for the three and nine months ended June 30, 2016 and 2015 is presented below. Note that this presentation does not reflect the financial impact arising from the hedged physical transaction. Therefore, this presentation is not indicative of the economic gross profit we realized when the underlying physical and financial transactions were settled. Three Months Ended June 30, 2016 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (12,347 ) $ (12,347 ) Gain arising from ineffective portion of commodity contracts — 66 66 Total impact on purchased gas cost — (12,281 ) (12,281 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (137 ) — (137 ) Total Impact from Cash Flow Hedges $ (137 ) $ (12,281 ) $ (12,418 ) Three Months Ended June 30, 2015 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (16,488 ) $ (16,488 ) Gain arising from ineffective portion of commodity contracts — 11 11 Total impact on purchased gas cost — (16,477 ) (16,477 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (137 ) — (137 ) Total Impact from Cash Flow Hedges $ (137 ) $ (16,477 ) $ (16,614 ) Nine Months Ended June 30, 2016 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (48,015 ) $ (48,015 ) Gain arising from ineffective portion of commodity contracts — 84 84 Total impact on purchased gas cost — (47,931 ) (47,931 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (410 ) — (410 ) Total Impact from Cash Flow Hedges $ (410 ) $ (47,931 ) $ (48,341 ) Nine Months Ended June 30, 2015 Regulated Distribution Nonregulated Consolidated (In thousands) Loss reclassified from AOCI for effective portion of commodity contracts $ — $ (29,222 ) $ (29,222 ) Loss arising from ineffective portion of commodity contracts — (316 ) (316 ) Total impact on purchased gas cost — (29,538 ) (29,538 ) Net loss on settled interest rate agreements reclassified from AOCI into interest expense (717 ) — (717 ) Total Impact from Cash Flow Hedges $ (717 ) $ (29,538 ) $ (30,255 )
Other comprehensive income from hedging table	The following table summarizes the gains and losses arising from hedging transactions that were recognized as a component of other comprehensive income (loss), net of taxes, for the three and nine months ended June 30, 2016 and 2015 . The amounts included in the table below exclude gains and losses arising from ineffectiveness because those amounts are immediately recognized in the income statement as incurred. Three Months Ended Nine Months Ended 2016 2015 2016 2015 (In thousands) Increase (decrease) in fair value: Interest rate agreements $ (39,337 ) $ 54,388 $ (88,345 ) $ (30,436 ) Forward commodity contracts 10,573 1,505 (8,612 ) (37,397 ) Recognition of (gains) losses in earnings due to settlements: Interest rate agreements 87 87 260 455 Forward commodity contracts 7,532 10,058 29,290 17,826 Total other comprehensive income (loss) from hedging, net of tax (1) $ (21,145 ) $ 66,038 $ (67,407 ) $ (49,552 ) (1) Utilizing an income tax rate ranging from 37 percent to 39 percent based on the effective rates in each taxing jurisdiction.
Expected recognition in earnings of deferred gains/(losses) in AOCI table	The following amounts, net of deferred taxes, represent the expected recognition in earnings of the deferred losses recorded in AOCI associated with our financial instruments, based upon the fair values of these financial instruments as of June 30, 2016 . However, the table below does not include the expected recognition in earnings of our outstanding interest rate agreements as those instruments have not yet settled. Interest Rate Agreements Commodity Contracts Total (In thousands) Next twelve months $ (372 ) $ (4,992 ) $ (5,364 ) Thereafter (18,018 ) 233 (17,785 ) Total (1) $ (18,390 ) $ (4,759 ) $ (23,149 ) (1) Utilizing an income tax rate ranging from 37 percent to 39 percent based on the effective rates in each taxing jurisdiction.

Fair Value Measurements (Table)

Fair Value Measurements (Table)	9 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair value measurements table	The following tables summarize, by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of June 30, 2016 and September 30, 2015 . Assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) (1) Significant Other Unobservable Inputs (Level 3) Netting and Cash Collateral (2) June 30, 2016 (In thousands) Assets: Financial instruments Regulated distribution segment $ — $ 4,401 $ — $ — $ 4,401 Nonregulated segment — 52,119 — (47,164 ) 4,955 Total financial instruments — 56,520 — (47,164 ) 9,356 Hedged portion of gas stored underground 97,860 — — — 97,860 Available-for-sale securities Money market funds — 1,358 — — 1,358 Registered investment companies 39,068 — — — 39,068 Bonds — 31,319 — — 31,319 Total available-for-sale securities 39,068 32,677 — — 71,745 Total assets $ 136,928 $ 89,197 $ — $ (47,164 ) $ 178,961 Liabilities: Financial instruments Regulated distribution segment $ — $ 249,704 $ — $ (16,330 ) $ 233,374 Nonregulated segment — 69,901 — (69,901 ) — Total liabilities $ — $ 319,605 $ — $ (86,231 ) $ 233,374 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) (1) Significant Other Unobservable Inputs (Level 3) Netting and Cash Collateral (3) September 30, 2015 (In thousands) Assets: Financial instruments Regulated distribution segment $ — $ 746 $ — $ — $ 746 Nonregulated segment — 91,363 — (82,509 ) 8,854 Total financial instruments — 92,109 — (82,509 ) 9,600 Hedged portion of gas stored underground 43,901 — — — 43,901 Available-for-sale securities Money market funds — 1,072 — — 1,072 Registered investment companies 40,619 — — — 40,619 Bonds — 32,509 — — 32,509 Total available-for-sale securities 40,619 33,581 — — 74,200 Total assets $ 84,520 $ 125,690 $ — $ (82,509 ) $ 127,701 Liabilities: Financial instruments Regulated distribution segment $ — $ 120,107 $ — $ — $ 120,107 Nonregulated segment — 125,983 — (125,983 ) — Total liabilities $ — $ 246,090 $ — $ (125,983 ) $ 120,107 (1) Our Level 2 measurements consist of over-the-counter options and swaps which are valued using a market-based approach in which observable market prices are adjusted for criteria specific to each instrument, such as the strike price, notional amount or basis differences, municipal and corporate bonds which are valued based on the most recent available quoted market prices and money market funds which are valued at cost. (2) This column reflects adjustments to our gross financial instrument assets and liabilities to reflect netting permitted under our master netting agreements and the relevant authoritative accounting literature. In addition, as of June 30, 2016 , we had $16.3 million of cash held in margin accounts to collateralize certain regulated distribution financial instruments, which were used to offset current and noncurrent risk management liabilities. As of June 30, 2016 , we also had $22.7 million of cash held in margin accounts to collateralize certain nonregulated financial instruments. Of this amount, $18.7 million was used to offset current and noncurrent risk management liabilities under master netting arrangements with the remaining $4.0 million classified as current risk management assets. (3) This column reflects adjustments to our gross financial instrument assets and liabilities to reflect netting permitted under our master netting agreements and the relevant authoritative accounting literature. In addition, as of September 30, 2015 , we had $43.5 million of cash held in margin accounts to collateralize certain nonregulated financial instruments. Of this amount, $34.6 million was used to offset current and noncurrent risk management liabilities under master netting arrangements with the remaining $8.9 million is classified as current risk management assets.
Schedule of Available-for-sale Securities Reconciliation Table	Available-for-sale securities are comprised of the following: Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value (In thousands) As of June 30, 2016 Domestic equity mutual funds $ 28,377 $ 5,549 $ (962 ) $ 32,964 Foreign equity mutual funds 5,357 747 — 6,104 Bonds 31,147 175 (3 ) 31,319 Money market funds 1,358 — — 1,358 $ 66,239 $ 6,471 $ (965 ) $ 71,745 As of September 30, 2015 Domestic equity mutual funds $ 27,643 $ 7,332 $ (456 ) $ 34,519 Foreign equity mutual funds 5,261 905 (66 ) 6,100 Bonds 32,423 106 (20 ) 32,509 Money market funds 1,072 — — 1,072 $ 66,399 $ 8,343 $ (542 ) $ 74,200
Other fair value measurements table	The following table presents the carrying value and fair value of our debt as of June 30, 2016 and September 30, 2015 : June 30, 2016 September 30, 2015 (In thousands) Carrying Amount $ 2,460,000 $ 2,460,000 Fair Value $ 2,858,540 $ 2,669,323

Nature of Business (Details)

Nature of Business (Details) customers in Millions	Jun. 30, 2016statecustomersregulated_gas_distributions_divisions
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Customers, Regulated Distribution | customers	3
Number of Divisions, Regulated Distribution | regulated_gas_distributions_divisions	6
Number of States in which Entity Operates | state	8

Unaudited Interim Financial Inf

Unaudited Interim Financial Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended	9 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Sep. 30, 2015
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings		$ 1,273,057			$ 1,273,057		$ 1,073,029
Income tax expense (benefit)		(39,106)	$ (34,005)		(180,719)	$ (176,182)
Regulatory Asset [Line Items]
Regulatory assets		184,828			184,828		192,339
Regulatory asset - future recoverable pension costs		12,900			12,900		16,600
Regulatory Liabilities [Line Items]
Regulatory liabilities		535,198			535,198		524,532
Regulatory Cost of Removal [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		486,290			486,290		483,676
Deferred Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		34,362			34,362		28,100
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		9,063			9,063		9,063
Other [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		5,483			5,483		3,693
Pension And Postretirement Benefit Costs [Member]
Regulatory Asset [Line Items]
Regulatory assets	[1]	110,425			110,425		121,183
Infrastructure Mechanisms [Member]
Regulatory Asset [Line Items]
Regulatory assets	[2]	31,090			31,090		32,813
Deferred Gas Costs [Member]
Regulatory Asset [Line Items]
Regulatory assets		3,390			3,390		9,715
Recoverable Loss On Reacquired Debt [Member]
Regulatory Asset [Line Items]
Regulatory assets		14,401			14,401		16,319
APT Annual Adjustment Mechanism [Member]
Regulatory Asset [Line Items]
Regulatory assets		2,976			2,976		1,002
Rate Case Costs [Member]
Regulatory Asset [Line Items]
Regulatory assets		1,640			1,640		1,533
Other [Member]
Regulatory Asset [Line Items]
Regulatory assets		20,906			20,906		$ 9,774
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards		$ 4,900			4,900
Income tax expense (benefit)				$ 3,300	$ 4,900
Adjustments for New Accounting Principle, Early Adoption [Member] | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards				14,500
Retained earnings				$ 14,500
[1]	Includes $12.9 million and $16.6 million of pension and postretirement expense deferred pursuant to regulatory authorization.
[2]	Infrastructure mechanisms in Texas and Louisiana allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consist of interest, depreciation and other taxes, until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)segment	Jun. 30, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			3
Segment Reporting Information Profit Loss [Abstract]
Total operating revenues	$ 632,916	$ 686,401	$ 2,671,430	$ 3,485,234
Purchased gas cost	225,605	304,728	1,302,545	2,159,538
Gross profit	407,311	381,673	1,368,885	1,325,696
Operating expenses
Operation and maintenance	137,444	132,447	395,958	384,489
Depreciation and amortization	73,459	68,444	216,670	204,059
Taxes, other than income	59,244	63,175	172,872	181,606
Total operating expenses	270,147	264,066	785,500	770,154
Operating income	137,164	117,607	583,385	555,542
Miscellaneous income (expense)	833	634	(1,061)	(2,634)
Interest charges	27,698	27,955	85,741	85,166
Income (loss) before income taxes	110,299	90,286	496,583	467,742
Income tax expense (benefit)	39,106	34,005	180,719	176,182
Net income (loss)	71,193	56,281	315,864	291,560
Capital expenditures	257,775	225,839	796,008	667,483
ASSETS
Net property, plant and equipment	8,053,547		8,053,547		$ 7,430,580
Investment in subsidiaries	0		0		0
Current assets
Cash and cash equivalents	66,206	43,153	66,206	43,153	28,653	$ 42,258
Assets from risk management activities	7,698		7,698		9,232
Other current assets	575,009		575,009		588,421
Intercompany receivables	0		0		0
Total current assets	648,913		648,913		626,306
Goodwill	742,702		742,702		742,702
Noncurrent assets from risk management activities	1,658		1,658		368
Deferred charges and other assets	280,548		280,548		292,989
Total assets	9,727,368		9,727,368		9,092,945
CAPITALIZATION AND LIABILITIES
Shareholders' equity	3,466,724		3,466,724		3,194,797
Long-term debt	2,205,645		2,205,645		2,455,388
Total capitalization	5,672,369		5,672,369		5,650,185
Current liabilities
Current maturities of long-term debt	250,000		250,000		0
Short-term debt	670,466		670,466		457,927
Liabilities from risk management activities	56,883		56,883		9,568
Other current liabilities	552,451		552,451		687,328
Intercompany payables	0		0		0
Total current liabilities	1,529,800		1,529,800		1,154,823
Deferred income taxes	1,585,500		1,585,500		1,411,315
Derivative Liability, Noncurrent	176,491		176,491		110,539
Regulatory cost of removal obligation	427,332		427,332		427,553
Pension and postretirement liabilities	283,579		283,579		287,373
Deferred credits and other liabilities	52,297		52,297		51,157
Total shareholders' equity and liabilities	9,727,368		9,727,368		9,092,945
Reportable Subsegments [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	632,916	686,401	2,671,430	3,485,234
Intersubsegment Eliminations [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	0	0	0	0
Regulated Distribution Segment [Member]
Segment Reporting Information Profit Loss [Abstract]
Total operating revenues	414,226	416,794	1,902,513	2,394,179
Purchased gas cost	138,845	149,775	884,529	1,397,113
Gross profit	275,381	267,019	1,017,984	997,066
Operating expenses
Operation and maintenance	100,859	98,552	291,388	288,962
Depreciation and amortization	58,916	55,491	173,913	165,730
Taxes, other than income	52,377	56,176	152,324	162,759
Total operating expenses	212,152	210,219	617,625	617,451
Operating income	63,229	56,800	400,359	379,615
Miscellaneous income (expense)	1,111	1,045	209	(1,221)
Interest charges	18,968	19,961	58,390	60,914
Income (loss) before income taxes	45,372	37,884	342,178	317,480
Income tax expense (benefit)	15,516	15,420	124,755	121,776
Net income (loss)	29,856	22,464	217,423	195,704
Capital expenditures	191,202	170,134	533,826	482,371
ASSETS
Net property, plant and equipment	6,067,548		6,067,548		5,670,306
Investment in subsidiaries	1,007,787		1,007,787		1,038,670
Current assets
Cash and cash equivalents	61,441		61,441		23,863
Assets from risk management activities	3,651		3,651		378
Other current assets	370,444		370,444		421,591
Intercompany receivables	981,651		981,651		887,713
Total current assets	1,417,187		1,417,187		1,333,545
Goodwill	575,449		575,449		575,449
Noncurrent assets from risk management activities	750		750		368
Deferred charges and other assets	258,370		258,370		270,372
Total assets	9,327,091		9,327,091		8,888,710
CAPITALIZATION AND LIABILITIES
Shareholders' equity	3,466,724		3,466,724		3,194,797
Long-term debt	2,205,645		2,205,645		2,455,388
Total capitalization	5,672,369		5,672,369		5,650,185
Current liabilities
Current maturities of long-term debt	250,000		250,000
Short-term debt	870,466		870,466		782,927
Liabilities from risk management activities	56,883		56,883		9,568
Other current liabilities	453,831		453,831		569,273
Intercompany payables	0		0		0
Total current liabilities	1,631,180		1,631,180		1,361,768
Deferred income taxes	1,093,755		1,093,755		1,008,091
Derivative Liability, Noncurrent	176,491		176,491		110,539
Regulatory cost of removal obligation	427,332		427,332		427,553
Pension and postretirement liabilities	283,579		283,579		287,373
Deferred credits and other liabilities	42,385		42,385		43,201
Total shareholders' equity and liabilities	9,327,091		9,327,091		8,888,710
Regulated Distribution Segment [Member] | Reportable Subsegments [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	411,982	415,160	1,896,636	2,389,037
Regulated Distribution Segment [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	2,244	1,634	5,877	5,142
Regulated Pipeline Segment [Member]
Segment Reporting Information Profit Loss [Abstract]
Total operating revenues	109,249	97,008	299,629	272,305
Purchased gas cost	0	0	0	0
Gross profit	109,249	97,008	299,629	272,305
Operating expenses
Operation and maintenance	29,083	26,572	83,302	74,029
Depreciation and amortization	13,409	11,816	39,358	34,945
Taxes, other than income	6,220	6,193	18,529	16,296
Total operating expenses	48,712	44,581	141,189	125,270
Operating income	60,537	52,427	158,440	147,035
Miscellaneous income (expense)	(359)	(211)	(1,164)	(842)
Interest charges	9,002	8,299	27,294	25,014
Income (loss) before income taxes	51,176	43,917	129,982	121,179
Income tax expense (benefit)	18,046	15,349	46,081	42,894
Net income (loss)	33,130	28,568	83,901	78,285
Capital expenditures	66,639	55,914	262,058	185,028
ASSETS
Net property, plant and equipment	1,935,087		1,935,087		1,706,449
Investment in subsidiaries	0		0		0
Current assets
Cash and cash equivalents	0		0		0
Assets from risk management activities	0		0		0
Other current assets	22,269		22,269		24,628
Intercompany receivables	0		0		0
Total current assets	22,269		22,269		24,628
Goodwill	132,542		132,542		132,542
Noncurrent assets from risk management activities	0		0		0
Deferred charges and other assets	21,976		21,976		17,288
Total assets	2,111,874		2,111,874		1,880,907
CAPITALIZATION AND LIABILITIES
Shareholders' equity	661,175		661,175		577,275
Long-term debt	0		0		0
Total capitalization	661,175		661,175		577,275
Current liabilities
Current maturities of long-term debt	0		0
Short-term debt	0		0		0
Liabilities from risk management activities	0		0		0
Other current liabilities	16,590		16,590		29,780
Intercompany payables	953,683		953,683		867,409
Total current liabilities	970,273		970,273		897,189
Deferred income taxes	480,336		480,336		406,254
Derivative Liability, Noncurrent	0		0		0
Regulatory cost of removal obligation	0		0		0
Pension and postretirement liabilities	0		0		0
Deferred credits and other liabilities	90		90		189
Total shareholders' equity and liabilities	2,111,874		2,111,874		1,880,907
Regulated Pipeline Segment [Member] | Reportable Subsegments [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	28,518	25,859	75,344	70,887
Regulated Pipeline Segment [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	80,731	71,149	224,285	201,418
Nonregulated Segment [Member]
Segment Reporting Information Profit Loss [Abstract]
Total operating revenues	214,555	278,769	774,474	1,179,379
Purchased gas cost	191,741	260,990	722,803	1,122,655
Gross profit	22,814	17,779	51,671	56,724
Operating expenses
Operation and maintenance	7,635	7,456	21,667	21,897
Depreciation and amortization	1,134	1,137	3,399	3,384
Taxes, other than income	647	806	2,019	2,551
Total operating expenses	9,416	9,399	27,085	27,832
Operating income	13,398	8,380	24,586	28,892
Miscellaneous income (expense)	574	345	1,245	897
Interest charges	221	240	1,408	706
Income (loss) before income taxes	13,751	8,485	24,423	29,083
Income tax expense (benefit)	5,544	3,236	9,883	11,512
Net income (loss)	8,207	5,249	14,540	17,571
Capital expenditures	(66)	(209)	124	84
ASSETS
Net property, plant and equipment	50,912		50,912		53,825
Investment in subsidiaries	0		0		(2,096)
Current assets
Cash and cash equivalents	4,765		4,765		4,790
Assets from risk management activities	4,047		4,047		8,854
Other current assets	391,265		391,265		480,503
Intercompany receivables	0		0		0
Total current assets	400,077		400,077		494,147
Goodwill	34,711		34,711		34,711
Noncurrent assets from risk management activities	908		908		0
Deferred charges and other assets	202		202		5,329
Total assets	486,810		486,810		585,916
CAPITALIZATION AND LIABILITIES
Shareholders' equity	346,612		346,612		461,395
Long-term debt	0		0		0
Total capitalization	346,612		346,612		461,395
Current liabilities
Current maturities of long-term debt	0		0
Short-term debt	0		0		0
Liabilities from risk management activities	0		0		0
Other current liabilities	90,999		90,999		99,480
Intercompany payables	27,968		27,968		20,304
Total current liabilities	118,967		118,967		119,784
Deferred income taxes	11,409		11,409		(3,030)
Derivative Liability, Noncurrent	0		0		0
Regulatory cost of removal obligation	0		0		0
Pension and postretirement liabilities	0		0		0
Deferred credits and other liabilities	9,822		9,822		7,767
Total shareholders' equity and liabilities	486,810		486,810		585,916
Nonregulated Segment [Member] | Reportable Subsegments [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	192,416	245,382	699,450	1,025,310
Nonregulated Segment [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	22,139	33,387	75,024	154,069
Intersegment Elimination [Member]
Segment Reporting Information Profit Loss [Abstract]
Total operating revenues	(105,114)	(106,170)	(305,186)	(360,629)
Purchased gas cost	(104,981)	(106,037)	(304,787)	(360,230)
Gross profit	(133)	(133)	(399)	(399)
Operating expenses
Operation and maintenance	(133)	(133)	(399)	(399)
Depreciation and amortization	0	0	0	0
Taxes, other than income	0	0	0	0
Total operating expenses	(133)	(133)	(399)	(399)
Operating income	0	0	0	0
Miscellaneous income (expense)	(493)	(545)	(1,351)	(1,468)
Interest charges	(493)	(545)	(1,351)	(1,468)
Income (loss) before income taxes	0	0	0	0
Income tax expense (benefit)	0	0	0	0
Net income (loss)	0	0	0	0
Capital expenditures	0	0	0	0
ASSETS
Net property, plant and equipment	0		0		0
Investment in subsidiaries	(1,007,787)		(1,007,787)		(1,036,574)
Current assets
Cash and cash equivalents	0		0		0
Assets from risk management activities	0		0		0
Other current assets	(208,969)		(208,969)		(338,301)
Intercompany receivables	(981,651)		(981,651)		(887,713)
Total current assets	(1,190,620)		(1,190,620)		(1,226,014)
Goodwill	0		0		0
Noncurrent assets from risk management activities	0		0		0
Deferred charges and other assets	0		0		0
Total assets	(2,198,407)		(2,198,407)		(2,262,588)
CAPITALIZATION AND LIABILITIES
Shareholders' equity	(1,007,787)		(1,007,787)		(1,038,670)
Long-term debt	0		0		0
Total capitalization	(1,007,787)		(1,007,787)		(1,038,670)
Current liabilities
Current maturities of long-term debt	0		0
Short-term debt	(200,000)		(200,000)		(325,000)
Liabilities from risk management activities	0		0		0
Other current liabilities	(8,969)		(8,969)		(11,205)
Intercompany payables	(981,651)		(981,651)		(887,713)
Total current liabilities	(1,190,620)		(1,190,620)		(1,223,918)
Deferred income taxes	0		0		0
Derivative Liability, Noncurrent	0		0		0
Regulatory cost of removal obligation	0		0		0
Pension and postretirement liabilities	0		0		0
Deferred credits and other liabilities	0		0		0
Total shareholders' equity and liabilities	(2,198,407)		(2,198,407)		$ (2,262,588)
Intersegment Elimination [Member] | Reportable Subsegments [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	0	0	0	0
Intersegment Elimination [Member] | Intersubsegment Eliminations [Member]
Segment Reporting Information Profit Loss [Abstract]
Revenues	$ (105,114)	$ (106,170)	$ (305,186)	$ (360,629)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income (loss)	$ 71,193	$ 56,281	$ 315,864	$ 291,560
Income allocated to participating securities	108	111	496	596
Income available to common shareholders	$ 71,085	$ 56,170	$ 315,368	$ 290,964
Basic and diluted net income per share	$ 0.69	$ 0.55	$ 3.06	$ 2.86
Weighted Average Number of Shares Outstanding, Basic and Diluted	103,750	102,000	103,137	101,776

Debt (Details)

Debt (Details) - USD ($)	Oct. 15, 2014	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Sep. 30, 2014
Debt Instrument [Line Items]
Net Proceeds From Issuance Of Debt	$ 494,000,000
Debt Instrument Carrying Amount		$ 2,460,000,000	$ 2,460,000,000	$ 2,460,000,000
Debt Instrument, Unamortized Discount		4,355,000	4,612,000	4,355,000
Current maturities of long-term debt		250,000,000	0	250,000,000
Long-term debt		2,205,645,000	2,455,388,000	2,205,645,000
Extinguishment of Debt, Amount	500,000,000
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		1,300,000,000		1,300,000,000
Long Term Debt Other Disclosures [Abstract]
Commercial Paper		$ 670,500,000	457,900,000	$ 670,500,000
Required by Covenant [Member]
Line Of Credit Facility [Line Items]
Ratio of Total Debt to Total Capital		70.00%		70.00%
Actual [Member]
Line Of Credit Facility [Line Items]
Ratio of Total Debt to Total Capital		49.00%		49.00%
Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		$ 1,300,000,000		$ 1,300,000,000
Unregulated Operation [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity		33,000,000		33,000,000
Minimum [Member] | Required by Covenant [Member]
Line Of Credit Facility [Line Items]
Excess of Debt		15,000,000		15,000,000
Maximum [Member] | Required by Covenant [Member]
Line Of Credit Facility [Line Items]
Excess of Debt		100,000,000		100,000,000
Five Year Unsecured Revolving Credit Agreement [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity with Accordion Feature		1,500,000,000		1,500,000,000
Five Year Unsecured Revolving Credit Agreement [Member] | Commercial Paper [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		1,250,000,000		1,250,000,000
Five Year Unsecured Revolving Credit Agreement [Member] | Uncommitted Revolving Credit Facility [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		1,250,000,000		1,250,000,000
$15 Million Revolving Credit Note [Member] | Unsecured Revolving Credit Note [Member] | Unregulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		15,000,000		15,000,000
$25 Million Bank Loan Agreement [Member] | Unsecured Loan Agreement [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		25,000,000		25,000,000
$10 Million Revolving Credit Note [Member] | Unsecured Revolving Credit Note [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		10,000,000		10,000,000
Line of Credit Facility, Remaining Borrowing Capacity		4,100,000		4,100,000
Uncommitted Revolving Credit Facility and Promissory Note (AEH to AEC) [Member] | Uncommitted Revolving Credit Facility [Member] | Regulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		500,000,000		500,000,000
Uncommitted Revolving Credit Facility and Promissory Note (AEC to AEH) [Member] | Uncommitted Revolving Credit Facility [Member] | Unregulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		500,000,000		$ 500,000,000
Debt Instrument, Basis Spread on Variable Rate				3.00%
$25 Million Uncommitted Facility [Member] | Uncommitted Revolving Credit Facility [Member] | Unregulated Operation [Member]
Line Of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity		25,000,000		$ 25,000,000
Unsecured Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 250,000,000	$ 250,000,000	$ 250,000,000
Debt Instrument, Interest Rate, Stated Percentage		6.35%	6.35%	6.35%
Debt Instrument, Maturity Date		Jun. 15, 2017	Jun. 15, 2017
Unsecured Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 450,000,000	$ 450,000,000	$ 450,000,000
Debt Instrument, Interest Rate, Stated Percentage		8.50%	8.50%	8.50%
Debt Instrument, Maturity Date		Mar. 15, 2019	Mar. 15, 2019
Unsecured Senior Notes Due 2034 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 200,000,000	$ 200,000,000	$ 200,000,000
Debt Instrument, Interest Rate, Stated Percentage		5.95%	5.95%	5.95%
Debt Instrument, Maturity Date		Oct. 15, 2034	Oct. 15, 2034
Unsecured Senior Notes Due 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 400,000,000	$ 400,000,000	$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage		5.50%	5.50%	5.50%
Debt Instrument, Maturity Date		Jun. 15, 2041	Jun. 15, 2041
Unsecured Senior Notes Due 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 500,000,000	$ 500,000,000	$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.15%	4.15%	4.15%
Debt Instrument, Maturity Date		Jan. 15, 2043	Jan. 15, 2043
Unsecured Senior Notes Due 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.125%	4.125%	4.125%	4.125%
Debt Instrument, Maturity Date		Oct. 15, 2044	Oct. 15, 2044
Debt Instrument, Interest Rate, Effective Percentage	4.086%
Medium Term Notes Due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 10,000,000	$ 10,000,000	$ 10,000,000
Debt Instrument, Interest Rate, Stated Percentage		6.67%	6.67%	6.67%
Debt Instrument, Maturity Date		Dec. 15, 2025	Dec. 15, 2025
Unsecured Debentures Due 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount		$ 150,000,000	$ 150,000,000	$ 150,000,000
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%	6.75%
Debt Instrument, Maturity Date		Jul. 15, 2028	Jul. 15, 2028
Unsecured Senior Notes Due 2014 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount					$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage					4.95%

Shareholders' Equity Components

Shareholders' Equity Components (Details) - USD ($)	3 Months Ended	9 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Shareholders' equity, beginning balance		$ 3,194,797,000
Shareholders' equity, ending balance	$ 3,466,724,000	$ 3,466,724,000
Shareholders' Equity Other Disclosures [Abstract]
Share Repurchase Program - Shares Purchased		0	0
Debt and Equity Securities Authorized for Issuance	2,500,000,000	$ 2,500,000,000
Debt And Equity Securities Available For Issuance	2,400,000,000	2,400,000,000
ATM Equity Distribution Offering Price, Maximum Amount	$ 200,000,000	$ 200,000,000
ATM Equity Distribution, Shares Issued	1,360,756
ATM Agent Commission on Proceeds, percentage	1.00%	1.00%
ATM Equity Distribution, Net Proceeds	$ 98,700,000
ATM Equity Distribution, Gross Proceeds	100,000,000
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Shareholders' equity, beginning balance		$ 4,949,000	$ 7,662,000
Other comprehensive income (loss) before reclassifications		(1,417,000)	30,000
Amounts reclassified from accumulated other comprehensive income		(79,000)	(326,000)
Net current-period other comprehensive income (loss)		(1,496,000)	(296,000)
Shareholders' equity, ending balance	3,453,000	3,453,000	7,366,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Shareholders' equity, beginning balance		(88,842,000)	(18,381,000)
Other comprehensive income (loss) before reclassifications		(88,345,000)	(30,436,000)
Amounts reclassified from accumulated other comprehensive income		260,000	455,000
Net current-period other comprehensive income (loss)		(88,085,000)	(29,981,000)
Shareholders' equity, ending balance	(176,927,000)	(176,927,000)	(48,362,000)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Shareholders' equity, beginning balance		(25,437,000)	(1,674,000)
Other comprehensive income (loss) before reclassifications		(8,612,000)	(37,397,000)
Amounts reclassified from accumulated other comprehensive income		29,290,000	17,826,000
Net current-period other comprehensive income (loss)		20,678,000	(19,571,000)
Shareholders' equity, ending balance	(4,759,000)	(4,759,000)	(21,245,000)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Shareholders' equity, beginning balance		(109,330,000)	(12,393,000)
Other comprehensive income (loss) before reclassifications		(98,374,000)	(67,803,000)
Amounts reclassified from accumulated other comprehensive income		29,471,000	17,955,000
Net current-period other comprehensive income (loss)		(68,903,000)	(49,848,000)
Shareholders' equity, ending balance	$ (178,233,000)	$ (178,233,000)	$ (62,241,000)

Shareholders' Equity AOCI Affec

Shareholders' Equity AOCI Affected Line Item in the Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operation and maintenance	$ (137,444)	$ (132,447)	$ (395,958)	$ (384,489)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	110,299	90,286	496,583	467,742
Income Tax Expense	(39,106)	(34,005)	(180,719)	(176,182)
Interest charges	(27,698)	(27,955)	(85,741)	(85,166)
Purchased gas cost	(225,605)	(304,728)	(1,302,545)	(2,159,538)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations	(7,619)	(9,823)	(29,471)	(17,955)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operation and maintenance		508	124	514
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest		508	124	514
Income Tax Expense		(186)	(45)	(188)
Income (loss) from continuing operations		322	79	326
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	(12,484)	(16,625)	(48,425)	(29,939)
Income Tax Expense	4,865	6,480	18,875	11,658
Income (loss) from continuing operations	(7,619)	(10,145)	(29,550)	(18,281)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Purchased gas cost	(12,347)	(16,488)	(48,015)	(29,222)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest charges	$ (137)	$ (137)	$ (410)	$ (717)

Shareholders' Equity Share-base

Shareholders' Equity Share-based Compensation Arrangement by Share-based Payment Award (Details) - shares	Mar. 29, 2016	Feb. 29, 2016	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	2,500,000	2,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			8,700,000

Interim Pension and Other Pos36

Interim Pension and Other Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pension Benefits [Member]
Components of net periodic pension cost [Abstract]
Service Cost	$ 4,698	$ 5,051	$ 14,093	$ 15,153
Interest Cost	7,095	6,698	21,284	20,095
Expected return on assets	(6,881)	(6,435)	(20,642)	(19,308)
Amortization of transition (asset)/obligation	0	0	0	0
Amortization of prior service (credit)/cost	(57)	(48)	(170)	(144)
Amortization of actuarial (gain) loss	3,319	3,916	9,959	11,749
Net periodic pension cost	$ 8,174	$ 9,182	$ 24,524	$ 27,545
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount Rate	4.55%	4.43%	4.55%	4.43%
Rate of compensation increase	3.50%	3.50%	3.50%	3.50%
Expected return on plan assets	7.00%	7.25%	7.00%	7.25%
Current Year Benefit Plan Contributions [Abstract]
Contributions Actual	$ 15,000
Other Benefits [Member]
Components of net periodic pension cost [Abstract]
Service Cost	2,705	$ 3,895	$ 8,117	$ 11,687
Interest Cost	3,106	3,596	9,318	10,789
Expected return on assets	(1,566)	(1,608)	(4,698)	(4,824)
Amortization of transition (asset)/obligation	21	69	62	205
Amortization of prior service (credit)/cost	(411)	(411)	(1,233)	(1,233)
Amortization of actuarial (gain) loss	(541)	0	(1,625)	0
Net periodic pension cost	$ 3,314	$ 5,541	$ 9,941	$ 16,624
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount Rate	4.55%	4.43%	4.55%	4.43%
Expected return on plan assets	4.45%	4.60%	4.45%	4.60%
Current Year Benefit Plan Contributions [Abstract]
Contributions Actual			$ 12,800
Other Benefits [Member] | Minimum [Member]
Current Year Benefit Plan Contributions [Abstract]
Defined Benefit Plan, Expected Contributions in Current Fiscal Year			15,000
Other Benefits [Member] | Maximum [Member]
Current Year Benefit Plan Contributions [Abstract]
Defined Benefit Plan, Expected Contributions in Current Fiscal Year			$ 25,000

Financial Instruments Descripti

Financial Instruments Descriptions (Details) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)MMcf	Jun. 30, 2015USD ($)
General Discussion Of Derivative Instruments And Hedging Activities [Abstract]
Minimum Hedge Percentage Of Anticipated Heating Season Gas			25.00%
Maximum Hedge Percentage Of Anticipated Heating Season Gas			50.00%
Hedge Percentage Of Actual Heating Season Gas			33.00%
Hedge Volume Of Actual Heating Season Gas | MMcf			23,000
Minimum Length Of Time Hedged In Cash Flow Hedge			1 month
Maximum Length Of Time Hedged In Cash Flow Hedge			54 months
Accumulated Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Interest Rate Agreements, Realized Gain (Loss), Net of Tax	$ (18.4)		$ (18.4)
Gain (Loss) On Hedge Ineffectiveness	13.6	$ 3.6	$ 18.1	$ (0.9)
Regulated Segments Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate			37.00%	37.00%
Nonregulated Segment Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate			39.00%	39.00%
Gain (Loss) On Derivative Instruments Not Designated Hedges Net Pretax	1.9	$ 3.7	$ (2.8)	$ 13.2
Interest Rate Hedges, Senior Notes 2017 Issuance [Member]
Derivative [Line Items]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	250		250
Anticipated Debt Issuance, Amount	$ 250		$ 250
Derivative, Average Forward Interest Rate	3.37%		3.37%
Interest Rate Hedges, Senior Notes 2019 Issuance [Member]
Derivative [Line Items]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	$ 450		$ 450
Anticipated Debt Issuance, Amount	$ 450		$ 450
Derivative, Average Forward Interest Rate	3.78%		3.78%

Financial Instruments Commodity

Financial Instruments Commodity Contract Volume (Details)	Jun. 30, 2016MMcf
Regulated Distribution Segment [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	10,002
Regulated Distribution Segment [Member] | Nondesignated [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	10,002
Regulated Distribution Segment [Member] | Fair Value Hedging [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	0
Regulated Distribution Segment [Member] | Cash Flow Hedging [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	0
Nonregulated Segment [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	61,335
Nonregulated Segment [Member] | Nondesignated [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	51,128
Nonregulated Segment [Member] | Fair Value Hedging [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	(35,118)
Nonregulated Segment [Member] | Cash Flow Hedging [Member]
Commodity Contract Outstanding Volumes [Line Items]
Investment Contract Volume	45,325

Financial Instruments Balance S

Financial Instruments Balance Sheet Location (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Derivatives Fair Value [Line Items]
Derivative Asset	$ 9,356	$ 9,600
Derivative Liability	(233,374)	(120,107)
Regulated Distribution Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	4,401	746
Derivative Asset, Contract Netting	0	0
Derivative Asset, Net of Contract Netting	4,401	746
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Asset	4,401	746
Derivative Liability, Fair Value, Gross Liability	(249,704)	(120,107)
Derivative Liability, Contract Netting	0	0
Derivative Liability, Net of Contract Netting	(249,704)	(120,107)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	16,330	0
Derivative Liability	(233,374)	(120,107)
Nonregulated Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	52,119	91,363
Derivative Asset, Contract Netting	(51,210)	(91,363)
Derivative Asset, Net of Contract Netting	909	0
Derivative, Collateral, Right to Reclaim Cash	4,046	8,854
Derivative Asset	4,955	8,854
Derivative Liability, Fair Value, Gross Liability	(69,901)	(125,983)
Derivative Liability, Contract Netting	51,210	91,363
Derivative Liability, Net of Contract Netting	(18,691)	(34,620)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	18,691	34,620
Derivative Liability	0	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(249,664)	(110,539)
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Other Current Assets [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Other Current Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Deferred Charges And Other Assets [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Deferred Charges And Other Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Other Current Liabilities [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(65,533)
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Other Current Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Deferred Credits And Other Liabilities [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(184,131)	(110,539)
Designated As Hedging Instrument [Member] | Regulated Distribution Segment [Member] | Deferred Credits And Other Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	14,060	11,806
Derivative Liability, Fair Value, Gross Liability	(39,511)	(45,985)
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Other Current Assets [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Other Current Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	10,149	11,680
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Deferred Charges And Other Assets [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Deferred Charges And Other Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3,911	126
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Other Current Liabilities [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Other Current Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(35,680)	(36,067)
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Deferred Credits And Other Liabilities [Member] | Interest Rate Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Designated As Hedging Instrument [Member] | Nonregulated Segment [Member] | Deferred Credits And Other Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(3,831)	(9,918)
Nondesignated [Member] | Regulated Distribution Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	4,401	746
Derivative Liability, Fair Value, Gross Liability	(40)	(9,568)
Nondesignated [Member] | Regulated Distribution Segment [Member] | Other Current Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3,651	378
Nondesignated [Member] | Regulated Distribution Segment [Member] | Deferred Charges And Other Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	750	368
Nondesignated [Member] | Regulated Distribution Segment [Member] | Other Current Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(40)	(9,568)
Nondesignated [Member] | Regulated Distribution Segment [Member] | Deferred Credits And Other Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Nondesignated [Member] | Nonregulated Segment [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	38,059	79,557
Derivative Liability, Fair Value, Gross Liability	(30,390)	(79,998)
Nondesignated [Member] | Nonregulated Segment [Member] | Other Current Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	27,247	65,239
Nondesignated [Member] | Nonregulated Segment [Member] | Deferred Charges And Other Assets [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	10,812	14,318
Nondesignated [Member] | Nonregulated Segment [Member] | Other Current Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(20,407)	(65,780)
Nondesignated [Member] | Nonregulated Segment [Member] | Deferred Credits And Other Liabilities [Member] | Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ (9,983)	$ (14,218)

Financial Instruments Fair Valu

Financial Instruments Fair Value Hedges and Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Effect of Fair Value Hedges on Results of Operations [Abstract]
Commodity contracts	$ (22,146)	$ (1,715)	$ (11,808)	$ 5,754
Fair value adjustment for natural gas inventory designated as the hedged item	35,630	5,350	29,852	(6,291)
Total (increase) decrease to purchased gas cost	13,484	3,635	18,044	(537)
Basis ineffectiveness	(684)	599	(1,490)	908
Timing ineffectiveness	14,168	3,036	19,534	(1,445)
Cash Flow Hedge [Line Items]
Gain (loss) reclassified from AOCI into purchased gas cost for effective portion of commodity contracts	(12,347)	(16,488)	(48,015)	(29,222)
Gain (loss) arising from ineffective portion of commodity contracts	66	11	84	(316)
Total impact on purchased gas cost	(12,281)	(16,477)	(47,931)	(29,538)
Loss on settled Treasury Lock agreements reclassified from AOCI into interest expense	(137)	(137)	(410)	(717)
Total Impact from Cash Flow Hedges	(12,418)	(16,614)	(48,341)	(30,255)
Regulated Distribution Segment [Member]
Cash Flow Hedge [Line Items]
Gain (loss) reclassified from AOCI into purchased gas cost for effective portion of commodity contracts	0	0	0	0
Gain (loss) arising from ineffective portion of commodity contracts	0	0	0	0
Total impact on purchased gas cost	0	0	0	0
Loss on settled Treasury Lock agreements reclassified from AOCI into interest expense	(137)	(137)	(410)	(717)
Total Impact from Cash Flow Hedges	(137)	(137)	(410)	(717)
Nonregulated Segment [Member]
Cash Flow Hedge [Line Items]
Gain (loss) reclassified from AOCI into purchased gas cost for effective portion of commodity contracts	(12,347)	(16,488)	(48,015)	(29,222)
Gain (loss) arising from ineffective portion of commodity contracts	66	11	84	(316)
Total impact on purchased gas cost	(12,281)	(16,477)	(47,931)	(29,538)
Loss on settled Treasury Lock agreements reclassified from AOCI into interest expense	0	0	0	0
Total Impact from Cash Flow Hedges	$ (12,281)	$ (16,477)	$ (47,931)	$ (29,538)

Financial Instruments Other Com

Financial Instruments Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Interest rate agreements fair value	$ (39,337)	$ 54,388	$ (88,345)	$ (30,436)
Forward commodity contracts fair value	10,573	1,505	(8,612)	(37,397)
Interest rate agreements	87	87	260	455
Forward commodity contracts	7,532	10,058	29,290	17,826
Total other comprehensive income (loss) from hedging, net of tax	$ (21,145)	$ 66,038	(67,407)	$ (49,552)
Expected Earnings [Line Items]
Interest Rate Agreement Gain (Loss) Reclassified To Earnings			(18,390)
Commodity Contract Gain (Loss) Reclassified To Earnings			(4,759)
Total Hedge Gain (Loss) Reclassified To Earnings			(23,149)
Next Twelve Months [Member]
Expected Earnings [Line Items]
Interest Rate Agreement Gain (Loss) Reclassified To Earnings			(372)
Commodity Contract Gain (Loss) Reclassified To Earnings			(4,992)
Total Hedge Gain (Loss) Reclassified To Earnings			(5,364)
Thereafter [Member]
Expected Earnings [Line Items]
Interest Rate Agreement Gain (Loss) Reclassified To Earnings			(18,018)
Commodity Contract Gain (Loss) Reclassified To Earnings			233
Total Hedge Gain (Loss) Reclassified To Earnings			$ (17,785)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	$ (47,164)	$ (82,509)
Derivative Asset	9,356	9,600
Hedged portion of gas stored underground	97,860	43,901
Available-for-sale Securities	71,745	74,200
Total assets	178,961	127,701
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(86,231)	(125,983)
Derivative Liability	233,374	120,107
Additional Fair Value Elements [Abstract]
Debt Instrument Carrying Amount	2,460,000	2,460,000
Debt Instrument Fair Value	2,858,540	2,669,323
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,358	1,072
Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	39,068	40,619
Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	31,319	32,509
Regulated Distribution Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0	0
Derivative Asset	4,401	746
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(16,330)	0
Derivative Liability	233,374	120,107
Cash Held In Margin Accounts Classified Current Risk Management Asset	0	0
Cash Held In Margin Accounts Offset Current Risk Management Liabilities	16,330	0
Nonregulated Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(47,164)	(82,509)
Derivative Asset	4,955	8,854
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(69,901)	(125,983)
Derivative Liability	0	0
Derivative, Cash Collateral	22,700	43,500
Cash Held In Margin Accounts Classified Current Risk Management Asset	4,046	8,854
Cash Held In Margin Accounts Offset Current Risk Management Liabilities	18,691	34,620
Fair Value Inputs Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Hedged portion of gas stored underground	97,860	43,901
Available-for-sale Securities	39,068	40,619
Total assets	136,928	84,520
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0	0
Fair Value Inputs Level 1 [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	39,068	40,619
Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 1 [Member] | Regulated Distribution Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0	0
Fair Value Inputs Level 1 [Member] | Nonregulated Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0	0
Fair Value Inputs Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	56,520	92,109
Hedged portion of gas stored underground	0	0
Available-for-sale Securities	32,677	33,581
Total assets	89,197	125,690
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	319,605	246,090
Fair Value Inputs Level 2 [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,358	1,072
Fair Value Inputs Level 2 [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 2 [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	31,319	32,509
Fair Value Inputs Level 2 [Member] | Regulated Distribution Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	4,401	746
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	249,704	120,107
Fair Value Inputs Level 2 [Member] | Nonregulated Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	52,119	91,363
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	69,901	125,983
Fair Value Inputs Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Hedged portion of gas stored underground	0	0
Available-for-sale Securities	0	0
Total assets	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0	0
Fair Value Inputs Level 3 [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 3 [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 3 [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value Inputs Level 3 [Member] | Regulated Distribution Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0	0
Fair Value Inputs Level 3 [Member] | Nonregulated Segment [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	$ 0	$ 0

Fair Value Measurements Availab

Fair Value Measurements Available-For-Sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Schedule Of Available For Sale Securities [Line Items]
Available For Sale Securities Amortized Cost	$ 66,239	$ 66,399
Gross Unrealized Gain	6,471	8,343
Gross Unrealized Loss	(965)	(542)
Fair value	71,745	74,200
Available-for-sale Securities, Other Disclosure Items [Abstract]
Available-for-sale Securities, Supplemental Executive Benefit Plans	40,400	41,700
Equity Funds Domestic [Member]
Schedule Of Available For Sale Securities [Line Items]
Available For Sale Securities Amortized Cost	28,377	27,643
Gross Unrealized Gain	5,549	7,332
Gross Unrealized Loss	(962)	(456)
Fair value	32,964	34,519
Equity Funds Foreign [Member]
Schedule Of Available For Sale Securities [Line Items]
Available For Sale Securities Amortized Cost	5,357	5,261
Gross Unrealized Gain	747	905
Gross Unrealized Loss	0	(66)
Fair value	6,104	6,100
Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available For Sale Securities Amortized Cost	31,147	32,423
Gross Unrealized Gain	175	106
Gross Unrealized Loss	(3)	(20)
Fair value	31,319	32,509
Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available For Sale Securities Amortized Cost	1,358	1,072
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Fair value	$ 1,358	$ 1,072