Washington Gas Light (WGLCP) 10-Q 6 Aug 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document Information [Line Items]
Entity Registrant Name	WGL Holdings Inc.
Entity Central Index Key	1,103,601
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		49,728,662
Washington Gas Light Company
Document Information [Line Items]
Entity Registrant Name	Washington Gas Light Company
Entity Central Index Key	104,819
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--09-30
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment
At original cost	$ 4,822,149	$ 4,582,764
Accumulated depreciation and amortization	(1,295,069)	(1,268,319)
Net property, plant and equipment	3,527,080	3,314,445
Current Assets
Cash and cash equivalents	66,051	8,811
Receivables
Accounts receivable	284,833	222,253
Gas costs and other regulatory assets	6,016	3,752
Unbilled revenues	106,672	96,314
Allowance for doubtful accounts	(26,111)	(23,341)
Net receivables	371,410	298,978
Materials and supplies—principally at average cost	20,452	23,647
Storage gas	147,506	333,602
Deferred income taxes	31,425	26,664
Prepaid taxes	9,760	66,578
Other prepayments	38,148	34,269
Derivatives	15,743	18,331
Assets held for sale	22,920	0
Other	25,012	24,635
Total current assets	748,427	835,515
Regulatory assets
Gas costs	179,392	191,346
Pension and other post-retirement benefits	175,026	192,981
Other	74,571	71,638
Prepaid post-retirement benefits	109,001	96,385
Derivatives	28,342	18,739
Investments in direct financing leases, capital leases	25,826	18,159
Investments in unconsolidated affiliates	121,290	100,528
Other	19,510	16,763
Total deferred charges and other assets	732,958	706,539
Total Assets	5,008,465	4,856,499
Capitalization
Common shareholders’ equity	1,266,373	1,246,576
Washington Gas Light Company preferred stock	28,173	28,173
Long-term debt	950,494	679,228
Total capitalization	2,245,040	1,953,977
Current Liabilities
Current maturities of long-term debt	45,000	20,000
Notes payable	156,000	453,500
Accounts payable and other accrued liabilities	275,615	313,221
Wages payable	18,906	19,995
Accrued interest	13,654	3,488
Dividends declared	23,330	22,449
Customer deposits and advance payments	73,331	68,318
Gas costs and other regulatory liabilities	29,852	22,563
Accrued taxes	35,752	14,133
Derivatives	58,836	48,555
Liabilities held for sale	1,621	0
Other	44,417	34,063
Total current liabilities	776,314	1,020,285
Deferred Credits
Unamortized investment tax credits	125,117	99,351
Deferred income taxes	672,339	660,908
Accrued pensions and benefits	125,741	120,446
Asset retirement obligations	178,783	175,203
Regulatory liabilities
Accrued asset removal costs	340,844	327,388
Other post-retirement benefits	80,965	86,428
Other	18,785	17,588
Derivatives	354,263	294,745
Other	90,274	100,180
Total deferred credits	$ 1,987,111	$ 1,882,237
Commitments and Contingencies (Note 13)
Total Capitalization and Liabilities	$ 5,008,465	$ 4,856,499
Washington Gas Light Company
Property, Plant and Equipment
At original cost	4,400,838	4,250,194
Accumulated depreciation and amortization	(1,245,555)	(1,228,130)
Net property, plant and equipment	3,155,283	3,022,064
Current Assets
Cash and cash equivalents	61,770	1,060
Receivables
Accounts receivable	157,893	121,419
Gas costs and other regulatory assets	6,016	3,752
Unbilled revenues	23,576	20,881
Allowance for doubtful accounts	(18,880)	(19,209)
Net receivables	168,605	126,843
Materials and supplies—principally at average cost	20,409	23,600
Storage gas	60,348	156,083
Deferred income taxes	17,484	22,916
Prepaid taxes	5,438	16,137
Other prepayments	12,459	14,272
Receivables from associated companies	4,838	4,821
Derivatives	7,244	3,884
Assets held for sale	22,920	0
Other	1	0
Total current assets	381,516	369,616
Regulatory assets
Gas costs	179,392	191,346
Pension and other post-retirement benefits	174,036	191,896
Other	74,503	71,584
Prepaid post-retirement benefits	108,282	95,660
Derivatives	12,291	9,455
Other	11,641	13,457
Total deferred charges and other assets	560,145	573,398
Total Assets	4,096,944	3,965,078
Capitalization
Common shareholders’ equity	1,120,717	1,050,166
Washington Gas Light Company preferred stock	28,173	28,173
Long-term debt	702,201	679,228
Total capitalization	1,851,091	1,757,567
Current Liabilities
Current maturities of long-term debt	45,000	20,000
Notes payable	0	89,000
Accounts payable and other accrued liabilities	128,968	176,467
Wages payable	17,483	18,290
Accrued interest	12,129	3,488
Dividends declared	20,221	19,722
Customer deposits and advance payments	73,084	68,318
Gas costs and other regulatory liabilities	29,852	22,563
Accrued taxes	57,609	24,610
Payables to associated companies	66,855	54,685
Derivatives	37,027	33,858
Liabilities held for sale	1,621	0
Other	6,030	7,199
Total current liabilities	495,879	538,200
Deferred Credits
Unamortized investment tax credits	5,851	6,479
Deferred income taxes	673,586	619,946
Accrued pensions and benefits	124,214	118,954
Asset retirement obligations	177,292	173,775
Regulatory liabilities
Accrued asset removal costs	340,844	327,388
Other post-retirement benefits	80,404	85,814
Other	18,785	17,588
Derivatives	292,920	260,789
Other	36,078	58,578
Total deferred credits	$ 1,749,974	$ 1,669,311
Commitments and Contingencies (Note 13)
Total Capitalization and Liabilities	$ 4,096,944	$ 3,965,078

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
OPERATING REVENUES
Utility		$ 185,179	$ 194,901	$ 1,173,396	$ 1,283,697
Non-utility		255,994	272,599	1,018,747	1,038,350
Total Operating Revenues	[1]	441,173	467,500	2,192,143	2,322,047
OPERATING EXPENSES
Utility cost of gas		59,286	64,448	499,128	710,436
Non-utility cost of energy-related sales		240,808	266,321	933,911	997,958
Operation and maintenance		98,642	89,964	295,309	277,805
Depreciation and Amortization		30,696	27,622	90,159	81,516
General taxes and other assessments		29,308	28,634	126,475	126,376
Total Operating Expenses		458,740	476,989	1,944,982	2,194,091
OPERATING INCOME (LOSS)		(17,567)	(9,489)	247,161	127,956
Equity in Earnings of Unconsolidated Affiliates		1,262	818	4,238	1,851
Other income (expenses)—net		2,329	(304)	(1,688)	257
Interest expense		13,140	9,503	38,704	28,020
INCOME (LOSS) BEFORE INCOME TAXES		(27,116)	(18,478)	211,007	102,044
INCOME TAX EXPENSE (BENEFIT)		(11,756)	(6,868)	80,364	33,152
NET INCOME (LOSS)		(15,360)	(11,610)	130,643	68,892
Dividends on Washington Gas Light Company preferred stock		330	330	990	990
NET INCOME (LOSS) APPLICABLE TO COMMON STOCK		$ (15,690)	$ (11,940)	$ 129,653	$ 67,902
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)		49,729	51,921	49,814	51,871
Diluted (in shares)		49,729	51,921	50,056	51,885
EARNINGS (LOSS) PER AVERAGE COMMON SHARE
Basic (in dollars per share)		$ (0.32)	$ (0.23)	$ 2.60	$ 1.31
Diluted (in dollars per share)		(0.32)	(0.23)	2.59	1.31
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)		$ 0.4625	$ 0.4400	$ 1.3650	$ 1.3000
Washington Gas Light Company
OPERATING REVENUES
Utility		$ 190,345	$ 197,752	$ 1,193,232	$ 1,304,975
OPERATING EXPENSES
Utility cost of gas		64,452	67,249	518,945	731,452
Operation and maintenance		80,077	75,286	240,714	223,798
Depreciation and Amortization		27,348	25,500	80,832	75,942
General taxes and other assessments		25,197	25,391	114,903	116,190
Total Operating Expenses		197,074	193,426	955,394	1,147,382
OPERATING INCOME (LOSS)		(6,729)	4,326	237,838	157,593
Other income (expenses)—net		(129)	(304)	(748)	(394)
Interest expense		10,637	9,422	31,465	27,694
INCOME (LOSS) BEFORE INCOME TAXES		(17,495)	(5,400)	205,625	129,505
INCOME TAX EXPENSE (BENEFIT)		(6,071)	(5,209)	77,404	41,383
NET INCOME (LOSS)		(11,424)	(191)	128,221	88,122
Dividends on Washington Gas Light Company preferred stock		330	330	990	990
NET INCOME (LOSS) APPLICABLE TO COMMON STOCK		$ (11,754)	$ (521)	$ 127,231	$ 87,132
[1]	Operating revenues are reported gross of revenue taxes. Revenue taxes of both the regulated utility and the retail energy-marketing segments include gross receipt taxes. Revenue taxes of the regulated utility segment also include public service commission fees, franchise fees and energy taxes. Operating revenue amounts in the “Eliminations” row represent total intersegment revenues associated with sales from the regulated utility segment to the retail energy-marketing segment. Midstream Energy Services’ cost of energy related sales is netted with its gross revenues.

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Net Income (Loss)		$ (15,360)		$ (11,610)	$ 130,643		$ 68,892
OTHER COMPREHENSIVE INCOME (LOSS) BEFORE INCOME TAXES:
Qualified cash flow hedging instruments	[1]	49		0	(7,994)		0
Pension and other post-retirement benefit plans
Change in prior service cost (credit)	[2]	(170)		6,204	(511)		6,135
Change in actuarial net loss	[2]	529		404	1,503		604
Total pension and other post-retirement benefit plans		359		6,608	992		6,739
INCOME TAX EXPENSE (BENEFIT) RELATED TO OTHER COMPREHENSIVE INCOME		163		2,622	(3,565)		2,674
OTHER COMPREHENSIVE INCOME (LOSS)		245		3,986	(3,437)		4,065
COMPREHENSIVE INCOME (LOSS)		(15,115)		(7,624)	127,206		72,957
Washington Gas Light Company
Net Income (Loss)		(11,424)		(191)	128,221		88,122
Pension and other post-retirement benefit plans
Change in prior service cost (credit)	[3]	(170)	[2]	6,204	(511)	[2]	6,135
Change in actuarial net loss	[3]	529	[2]	404	1,503	[2]	604
Total pension and other post-retirement benefit plans		359		6,608	992		6,739
INCOME TAX EXPENSE (BENEFIT) RELATED TO OTHER COMPREHENSIVE INCOME		143		2,622	394		2,674
OTHER COMPREHENSIVE INCOME (LOSS)		216		3,986	598		4,065
COMPREHENSIVE INCOME (LOSS)		$ (11,208)		$ 3,795	$ 128,819		$ 92,187
[1]	Cash flow hedging instruments represent interest rate swaps agreements on debt issuances. Refer to Note 8- Derivative and weather-related instruments for further discussion of the interest rate swap agreements.
[2]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14- Pension and other post-retirement benefit plans for additional details.
[3]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14-Pension and other post-retirement benefit plans for additional details.

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
OPERATING ACTIVITIES
Net income	$ 130,643	$ 68,892
ADJUSTMENTS TO RECONCILE NET INCOME TO NET CASH PROVIDED BY OPERATING ACTIVITIES
Depreciation and Amortization	90,159	81,516
Amortization of:
Other regulatory assets and liabilities—net	981	461
Debt related costs	911	843
Deferred income taxes—net	36,156	(37,009)
Accrued/deferred pension and other post-retirement benefit cost	20,091	27,056
Compensation expense related to stock-based awards	11,051	3,838
Provision for doubtful accounts	15,411	4,474
Impairment loss	5,625	2,760
Other non-cash charges (credits)—net	(617)	5,366
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable and unbilled revenues—net	(83,076)	(88,899)
Gas costs and other regulatory assets/liabilities—net	5,025	7,369
Storage gas	186,096	108,792
Prepaid taxes	56,818	6,519
Other prepayments	(3,879)	(7,903)
Accounts payable and other accrued liabilities	(17,877)	38,124
Wages payable	(1,089)	(1,179)
Customer deposits and advance payments	5,013	(11,562)
Unamortized investment tax credits	17,162	34,360
Accrued taxes	23,240	4,282
Accrued interest	10,166	7,844
Other current assets	3,609	10,389
Other current liabilities	10,354	813
Deferred gas costs—net	11,954	(150,552)
Deferred assets—other	(17,953)	1,673
Deferred liabilities—other	(65,401)	9,944
Derivatives	62,784	314,774
Other—net	(360)	(27)
Net Cash Provided by Operating Activities	512,997	442,958
FINANCING ACTIVITIES
Long-term debt issued	296,481	75,253
Long-term debt retired	0	(37,000)
Debt issuance costs	(2,744)	0
Notes payable issued (retired) —net	(297,500)	(135,600)
Dividends on common stock and preferred stock	(67,986)	(67,367)
Repurchase of common stock	(41,485)	0
Net Cash Used in Financing Activities	(113,234)	(164,714)
INVESTING ACTIVITIES
Capital expenditures (excluding AFUDC)	(317,043)	(241,450)
Investments in non-utility interests	(29,618)	(29,666)
Distributions from non-utility interests	4,138	2,315
Net Cash Used in Investing Activities	(342,523)	(268,801)
INCREASE IN CASH AND CASH EQUIVALENTS	57,240	9,443
Cash and Cash Equivalents at Beginning of Year	8,811	3,478
Cash and Cash Equivalents at End of Period	66,051	12,921
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Income taxes paid—net	4,604	14,240
Interest paid	27,822	19,620
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Project debt financing activities—net	(2,032)	253
Capital expenditure accruals included in accounts payable and other accrued liabilities	30,489	21,400
Dividends paid in common stock	0	3,967
Washington Gas Light Company
OPERATING ACTIVITIES
Net income	128,221	88,122
ADJUSTMENTS TO RECONCILE NET INCOME TO NET CASH PROVIDED BY OPERATING ACTIVITIES
Depreciation and Amortization	80,832	75,942
Amortization of:
Other regulatory assets and liabilities—net	981	461
Debt related costs	967	843
Deferred income taxes—net	28,568	(36,003)
Accrued/deferred pension and other post-retirement benefit cost	19,610	26,740
Compensation expense related to stock-based awards	12,518	2,597
Provision for doubtful accounts	10,520	2,914
Impairment loss	0	2,760
Other non-cash charges (credits)—net	2,344	1,959
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable and unbilled revenues—net	(50,035)	(94,146)
Gas costs and other regulatory assets/liabilities—net	5,025	7,369
Storage gas	95,735	25,850
Other prepayments	12,513	1,422
Accounts payable and other accrued liabilities	(18,939)	47,973
Wages payable	(807)	(1,133)
Customer deposits and advance payments	4,766	(11,562)
Accrued taxes	32,999	56,033
Accrued interest	8,641	7,844
Other current assets	3,980	3,626
Other current liabilities	452	10,798
Deferred gas costs—net	11,954	(150,552)
Deferred assets—other	(17,430)	1,695
Deferred liabilities—other	(9,013)	(9,192)
Derivatives	29,104	274,373
Other—net	(835)	(226)
Net Cash Provided by Operating Activities	392,671	336,507
FINANCING ACTIVITIES
Long-term debt issued	50,000	75,253
Long-term debt retired	0	(37,000)
Debt issuance costs	(722)	0
Notes payable issued (retired) —net	(89,000)	(124,500)
Dividends on common stock and preferred stock	(59,542)	(59,208)
Net Cash Used in Financing Activities	(99,264)	(145,455)
INVESTING ACTIVITIES
Capital expenditures (excluding AFUDC)	(232,697)	(180,195)
Net Cash Used in Investing Activities	(232,697)	(180,195)
INCREASE IN CASH AND CASH EQUIVALENTS	60,710	10,857
Cash and Cash Equivalents at Beginning of Year	1,060	0
Cash and Cash Equivalents at End of Period	61,770	10,857
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Income taxes paid—net	3,711	11,536
Interest paid	20,583	19,294
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Project debt financing activities—net	(2,032)	253
Capital expenditure accruals included in accounts payable and other accrued liabilities	$ 25,367	$ 13,865

Accounting Policies

Accounting Policies	9 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Accounting Policies	NOTE 1. ACCOUNTING POLICIES Basis of Presentation WGL Holdings, Inc. (WGL) is a holding company that owns all of the shares of common stock of Washington Gas Light Company (Washington Gas), a regulated natural gas utility, all of the shares of common stock of Washington Gas Resources Corporation (Washington Gas Resources) and Hampshire Gas Company (Hampshire). Washington Gas Resources owns all of the shares of common stock of four non-utility subsidiaries that include WGL Energy Services, Inc. (WGL Energy Services), WGL Energy Systems, Inc. (WGL Energy Systems), WGL Midstream, Inc. (WGL Midstream) and WGSW, Inc. (WGSW). Except where the content clearly indicates otherwise, “WGL,” “we,” “us” or “our” refers to the holding company or the consolidated entity of WGL Holdings, Inc. and all of its subsidiaries. Unless otherwise noted, these notes apply equally to WGL and Washington Gas. The condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Therefore, certain financial information and note disclosures accompanying annual financial statements prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) are omitted in this interim report. The interim consolidated financial statements and accompanying notes should be read in conjunction with the combined Annual Report on Form 10-K for WGL and Washington Gas for the fiscal year ended September 30, 2014. Due to the seasonal nature of our businesses, the results of operations for the periods presented in this report are not necessarily indicative of actual results for the full fiscal years ending September 30, 2015 and 2014 of either WGL or Washington Gas. The accompanying unaudited financial statements for WGL and Washington Gas reflect all normal recurring adjustments that are necessary, in our opinion, to present fairly the results of operations in accordance with GAAP. For a complete description of our accounting policies, refer to Note 1 of the Notes to Consolidated Financial Statements of the combined Annual Report on Form 10-K for WGL and Washington Gas for the fiscal year ended September 30, 2014. Assets Held for Sale At June 30, 2015 , the Springfield Operations Center met the criteria to be reported as held for sale. Among other things, those criteria specify that (a) the asset must be available for immediate sale in its present condition subject only to terms that are usual and customary for sales of such assets and (b) the sale of the asset must be probable, and its transfer expected to qualify for recognition as a completed sale, within one year, with certain exceptions. The assets and liabilities associated with the Springfield Operations Center were reported as "Assets held for sale" and "Liabilities held for sale" on WGL's and Washington Gas' balance sheets as of June 30, 2015 . Washington Gas recorded approximately $0.5 million in transaction fees in "Operations and maintenance expense" in the accompanying statements of income related to selling the facility. Storage Gas Valuations For Washington Gas and WGL Energy Services, storage gas inventories are stated at the lower-of-cost or market as determined using the first-in, first-out method. For WGL Midstream, storage gas inventory is stated at the lower-of-cost or market using the weighted average cost method. Interim period inventory losses attributable to lower-of-cost or market adjustments may be reversed if the market value of the inventory is recovered by the end of the same fiscal year. The following table shows the lower-of-cost or market (LCM) adjustments recorded to net income for the three and nine months ended June 30, 2015 and 2014. Lower-of-Cost or Market Adjustments Pre-Tax Increase (Decrease) to Net Income Three Months Ended June 30, Nine Months Ended June 30, (In millions) 2015 2014 2015 2014 WGL (a) Operating revenues - non-utility $ 0.9 $ (0.8 ) $ (19.6 ) $ (0.8 ) Washington Gas Utility cost of gas $ — $ — $ (1.0 ) $ (0.4 ) Total Consolidated $ 0.9 $ (0.8 ) $ (20.6 ) $ (1.2 ) (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. ACCOUNTING STANDARDS ADOPTED IN FISCAL YEAR 2015 Standard Description Date of adoption Effect on the financial statements or other significant matters ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (Topic 740) The standard requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar loss, or a tax credit carryforward. October 1, 2014 As a result of the implementation of this standard, we reduced our deferred tax assets by a portion of our unrecognized tax benefits. The adoption of this standard did not have a material effect on our financial statements. OTHER NEWLY ISSUED ACCOUNTING STANDARDS Standard Description Date of adoption Effect on the financial statements or other significant matters ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost The standard requires an entity to present debt issuance costs in the balance sheet as a direct deduction of the debt liability in a manner consistent with its accounting treatment of debt discounts. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis The standard changes the analysis to be performed in determining whether certain types of legal entities should be consolidated, specifically the analysis of limited partnerships and similar entities, fee arrangements and related party relationships. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) The standard establishes a comprehensive revenue recognition model clarifying the method used to determine the timing and requirements for revenue recognition from contracts with customers. The disclosure requirements under the new standard will enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. October 1, 2018 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements.

Accounts Payable and Other Accr

Accounts Payable and Other Accrued Liabilities	9 Months Ended
	Jun. 30, 2015
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable and Other Accrued Liabilities	NOTE 2. ACCOUNTS PAYABLE AND OTHER ACCRUED LIABILITIES The tables below provide details for the amounts included in “Accounts payable and other accrued liabilities” on the balance sheets for both WGL and Washington Gas. WGL Holdings, Inc. (In millions) June 30, 2015 September 30, 2014 Accounts payable—trade $ 234.6 $ 278.8 Employee benefits and payroll accruals 25.8 19.8 Other accrued liabilities 15.2 14.6 Total $ 275.6 $ 313.2 Washington Gas Light Company (In millions) June 30, 2015 September 30, 2014 Accounts payable—trade $ 96.4 $ 146.4 Employee benefits and payroll accruals 24.1 18.2 Other accrued liabilities 8.5 11.9 Total $ 129.0 $ 176.5

Short-Term Debt

Short-Term Debt	9 Months Ended
	Jun. 30, 2015
Short-term Debt [Abstract]
Short-Term Debt	NOTE 3. SHORT-TERM DEBT WGL and Washington Gas satisfy their short-term financing requirements through the sale of commercial paper or through bank borrowings. Due to the seasonal nature of the regulated utility and retail energy-marketing segments, short-term financing requirements can vary significantly during the year. Revolving credit agreements are maintained to support outstanding commercial paper and to permit short-term borrowing flexibility. The policy of each WGL and Washington Gas is to maintain bank credit facilities in amounts equal to or greater than the expected maximum commercial paper position. The following is a summary of committed credit available at June 30, 2015 and September 30, 2014 . Committed Credit Available (In millions) June 30, 2015 WGL (b) Washington Gas Total Consolidated Committed credit agreements Unsecured revolving credit facility, expires December 19, 2019 (a) $ 450.0 $ 350.0 $ 800.0 Less: Commercial Paper (156.0 ) — (156.0 ) Net committed credit available $ 294.0 $ 350.0 $ 644.0 Weighted average interest rate 0.27 % — % 0.27 % September 30, 2014 Committed credit agreements Unsecured revolving credit facility, expires April 3, 2017 (a) $ 450.0 $ 350.0 $ 800.0 Less: Commercial Paper (364.5 ) (89.0 ) (453.5 ) Net committed credit available $ 85.5 $ 261.0 $ 346.5 Weighted average interest rate 0.20 % 0.13 % 0.19 % (a) Both WGL and Washington Gas have the right to request extensions with the banks’ approval. WGL’s revolving credit facility permits it to borrow an additional $100 million , with the banks’ approval, for a total of $550 million . Washington Gas’ revolving credit facility permits it to borrow an additional $100 million , with the banks’ approval, for a total of $450 million . (b) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. In December 2014, both WGL and Washington Gas entered into a first amendment to their respective credit agreements, each dated April 3, 2012. The amendments extend the maturity date of the credit facilities from April 3, 2017 to December 19, 2019, provided that the credit facilities will terminate on September 30, 2017. Under the credit agreements, as amended, WGL and Washington Gas each have the right to request two one-year-extensions, with the banks' approval. At June 30, 2015 and September 30, 2014 , there were no outstanding bank loans from WGL’s or Washington Gas’ revolving credit facilities.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Jun. 30, 2015
Long-term Debt, by Current and Noncurrent [Abstract]
Long-Term Debt	NOTE 4. LONG-TERM DEBT UNSECURED NOTES WGL and Washington Gas issue long-term notes with individual terms regarding interest rates, maturities and call or put options. These notes can have maturity dates of one or more years from the date of issuance. At June 30, 2015 and September 30, 2014 , WGL had the capacity under a shelf registration to issue an unspecified amount of long-term senior notes debt securities. At September 30, 2014 Washington Gas had the capacity to issue up to $275.0 million of additional long-term Medium-Term Notes (MTNs) under a shelf registration that expired on May 31, 2015. Washington Gas intends to file a shelf registration in the fourth quarter of fiscal year 2015 to issue additional MTNs. The following tables show the outstanding notes as of June 30, 2015 and September 30, 2014 . Senior Notes, MTNs and Private Placement Notes Outstanding ($ In millions) WGL (a) Washington Gas Total Consolidated June 30, 2015 Long-term notes (b) $ 250.0 $ 741.0 $ 991.0 Weighted average interest rate 3.66 % 5.56 % 5.08 % September 30, 2014 Long-term notes (b) $ — $ 691.0 $ 691.0 Weighted average interest rate n/a 5.65 % 5.65 % (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. (b) Includes Senior Notes for WGL and both MTNs and private placement notes for Washington Gas. Represents face value including current maturities. The following tables show senior notes, MTN and private placement issuances and retirements for the nine months ended June 30, 2015 and 2014 . Senior Notes, MTNs and Private Placement Issuances and Retirements ($ In millions) Principal (b) Interest Rate Effective Cost (c) Nominal Maturity Date Nine Months Ended June 30, 2015 WGL (a) Issuances: 10/24/2014 $ 100.0 2.25 % 2.42 % 11/1/2019 10/24/2014 125.0 4.60 % 5.11 % 11/1/2044 12/16/2014 25.0 4.60 % 5.53 % 11/1/2044 Total $ 250.0 Washington Gas Issuances: 12/15/2014 $ 50.0 4.24 % 4.41 % 12/15/2044 Total $ 50.0 Total consolidated issuances $ 300.0 Nine Months Ended June 30, 2014 Washington Gas Issuances: 12/5/2013 $ 75.0 5.00 % 4.95 % 12/15/2043 Total $ 75.0 Retirements: 11/7/2013 $ 37.0 4.88 % n/a 11/7/2013 Total $ 37.0 (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. (b) Represents face amount. (c) The estimated effective cost of the issued notes, including consideration of issuance fees and hedge costs.

Common Shareholders' Equity

Common Shareholders' Equity	9 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Common Shareholders' Equity	NOTE 5. COMMON SHAREHOLDERS’ EQUITY The tables below reflect the components of “Common shareholders’ equity” for WGL and “Common shareholder’s equity” for Washington Gas for the nine months ended June 30, 2015 . WGL Holdings, Inc. Components of Common Shareholders’ Equity (In thousands) Common Stock Amount Paid-In Capital Retained Earnings Accumulated Other Comprehensive Loss, Net of Taxes Total Balance at September 30, 2014 $ 525,932 $ 11,847 $ 716,758 $ (7,961 ) $ 1,246,576 Net income — — 130,643 — 130,643 Other comprehensive loss — — — (3,437 ) (3,437 ) Repurchase of common stock (41,485 ) — — — (41,485 ) Stock-based compensation 1,009 1,934 — — 2,943 Dividends declared: Common stock — — (67,877 ) — (67,877 ) Preferred stock — — (990 ) — (990 ) Balance at June 30, 2015 $ 485,456 $ 13,781 $ 778,534 $ (11,398 ) $ 1,266,373 Washington Gas Light Company Components of Common Shareholder’s Equity (In thousands) Common Stock Amount Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income (Loss), Net of Taxes Total Balance at September 30, 2014 $ 46,479 $ 480,620 $ 529,480 $ (6,413 ) $ 1,050,166 Net income — — 128,221 — 128,221 Other comprehensive income — — — 598 598 Stock-based compensation — 1,773 — — 1,773 Dividends declared: Common stock — — (59,051 ) — (59,051 ) Preferred stock — — (990 ) — (990 ) Balance at June 30, 2015 $ 46,479 $ 482,393 $ 597,660 $ (5,815 ) $ 1,120,717 WGL had 49,728,662 and 50,656,553 shares issued of common stock at June 30, 2015 and September 30, 2014 , respectively. Washington Gas had 46,479,536 shares issued of common stock at both June 30, 2015 and September 30, 2014 .

Earnings Per Share

Earnings Per Share	9 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 6. EARNINGS PER SHARE Basic EPS of WGL is computed by dividing net income by the weighted average number of common shares outstanding during the reported period. Diluted EPS assumes the issuance of common shares pursuant to stock-based compensation plans at the beginning of the applicable period unless the effect of such issuance would be anti-dilutive. The following table reflects the computation of our basic and diluted EPS for the three and nine months ended June 30, 2015 and 2014 . Basic and Diluted EPS (in thousands, except per share data) Net Income (Loss) Applicable to Common Stock Shares Per Share Amount Three Months Ended June 30, 2015 Basic EPS $ (15,690 ) 49,729 $ (0.32 ) Stock-based compensation plans — — Diluted EPS $ (15,690 ) 49,729 $ (0.32 ) Three Months Ended June 30, 2014 Basic EPS $ (11,940 ) 51,921 $ (0.23 ) Stock-based compensation plans — — Diluted EPS $ (11,940 ) 51,921 $ (0.23 ) Nine Months Ended June 30, 2015 Basic EPS $ 129,653 49,814 $ 2.60 Stock-based compensation plans — 242 Diluted EPS $ 129,653 50,056 $ 2.59 Nine Months Ended June 30, 2014 Basic EPS $ 67,902 51,871 $ 1.31 Stock-based compensation plans — 14 Diluted EPS $ 67,902 51,885 $ 1.31 We incurred a net loss for the three months ended June 30, 2015 and June 30, 2014; therefore, all common shares issuable pursuant to stock-based compensation plans, were not considered in the diluted loss per share calculations due to the anti-dilutive effect of such shares. These shares include performance shares of 317,000 shares for the three months ended June 30, 2015, and weighted average stock option and dividend reinvestment shares of 5,000 shares and 2,000 shares, respectively, for the three months ended June 30, 2014. There were no anti-dilutive shares for the nine months ended June 30, 2015 or 2014.

Income Taxes

Income Taxes	9 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 7. INCOME TAXES As of June 30, 2015 and September 30, 2014 , our uncertain tax positions were approximately $31.1 million and $32.6 million , respectively, primarily due to the change in tax accounting for repairs. If the amounts of unrecognized tax benefits are eventually realized, it would not materially impact the effective tax rate. It is reasonably possible that the amount of the unrecognized tax benefit with respect to some of WGL’s and Washington Gas’ uncertain tax positions will significantly increase or decrease in the next 12 months. At this time, however, an estimate of the range of reasonably possible outcomes cannot be determined. Under ASC Topic 740, Income Taxes, Washington Gas recognizes any accrued interest associated with uncertain tax positions in interest expense and recognizes any accrued penalties associated with uncertain tax positions in other expenses in the statements of income. At June 30, 2015 , we did not have an accrual of interest expense related to uncertain tax positions. At September 30, 2014 , we had a total accrual of $0.1 million of interest expense related to uncertain tax positions included in other deferred credits in the accompanying balance sheets. WGL files a consolidated federal tax return and various other state returns. We are no longer subject to income tax examinations by the Internal Revenue Service for years ended prior to September 30, 2011. Substantially all state income tax years in major jurisdictions are closed for years ended prior to September 30, 2010. Washington Gas charged the Maryland portion of the Medicare Part D (Med D) regulatory asset to tax expense during the fiscal year ended September 30, 2012 based on positions taken by the Maryland Public Service Commission (PSC of MD) in Washington Gas’ rate case during that fiscal year that did not permit recovery. Washington Gas received an order in the first quarter of fiscal year ended September 30, 2014 from the PSC of MD that did allow recovery of the Med D regulatory asset over a five year amortization period beginning December 2013. Therefore, the reinstatement of the regulatory asset is reflected in the effective tax rate for the nine months ended June 30, 2014 .

Derivative and Weather Related

Derivative and Weather Related Instruments	9 Months Ended
	Jun. 30, 2015
Derivative Instrument Detail [Abstract]
Derivative and Weather-Related Instruments	NOTE 8. DERIVATIVE AND WEATHER-RELATED INSTRUMENTS DERIVATIVE INSTRUMENTS Regulated Utility Operations Washington Gas enters into contracts that qualify as derivative instruments and are accounted for under ASC Topic 815. These derivative instruments are recorded at fair value on our balance sheet and Washington Gas does not designate any derivatives as hedges under ASC Topic 815. Washington Gas’ derivative instruments relate to: (i) Washington Gas’ asset optimization program; (ii) managing price risk associated with the purchase of gas to serve utility customers and (iii) managing interest rate risk. Asset Optimization. Washington Gas optimizes the value of its long-term natural gas transportation and storage capacity resources during periods when these resources are not being used to physically serve utility customers. Specifically, Washington Gas utilizes its transportation capacity assets to benefit from favorable natural gas prices between different geographic locations and utilizes its storage capacity assets to benefit from favorable natural gas prices between different time periods. As part of this asset optimization program, Washington Gas enters into physical and financial derivative transactions in the form of forward, futures and option contracts with the primary objective of locking in operating margins that Washington Gas will ultimately realize. The derivatives used under this program are subject to mark-to-market accounting treatment while the capacity and transportation resources are not. Regulatory sharing mechanisms allow the profit from these transactions to be shared between Washington Gas’ shareholders and customers; therefore, any changes in fair value are recorded through earnings, or as regulatory assets or liabilities to the extent that gains and losses associated with these derivative instruments will be included in the rates charged to customers when they are realized. Valuation changes for the portion of net profits to be retained for shareholders may cause significant period-to-period volatility in earnings from unrealized gains and losses. This volatility does not change the locked-in operating margins that Washington Gas expects to ultimately realize from these transactions through the use of its storage and transportation capacity resources. All physically and financially settled contracts under our asset optimization program are reported on a net basis in the statements of income in “Utility cost of gas.” Total net margins recorded to “Utility cost of gas” after sharing and management fees associated with all asset optimization transactions for the three months ended June 30, 2015 was a loss of $2.9 million including an unrealized loss of $10.4 million . During the three months ended June 30, 2014 we recorded a gain of $1.9 million including an unrealized loss of $1.2 million . Total net margins recorded for the nine months ended June 30, 2015 was a gain of $14.2 million including an unrealized loss of $13.3 million . During the nine months ended June 30, 2014 , we recorded a loss of $78.3 million including an unrealized loss of $105.3 million . Managing Price Risk. To manage price risk associated with acquiring natural gas supply for utility customers, Washington Gas enters into forward contracts, option contracts, financial contracts and other contracts, as authorized by its regulators. These instruments are accounted for as derivative instruments. Any gains and losses associated with these derivatives are recorded as regulatory liabilities or assets, respectively, to reflect the rate treatment for these economic hedging activities. Managing Interest-Rate Risk . Washington Gas utilizes derivative instruments that are designed to minimize the risk of interest-rate volatility associated with planned issuances of debt securities. Any gains and losses associated with these types of derivatives are recorded as regulatory liabilities or assets, respectively, and amortized in accordance with regulatory requirements, typically over the life of the newly issued debt. Non-Utility Operations Asset Optimization. WGL Midstream enters into derivative contracts for the purpose of optimizing its storage and transportation capacity as well as managing the transportation and storage assets on behalf of third parties. WGL Midstream does not designate these derivatives as hedges under ASC Topic 815; therefore, changes in the fair value of these derivative instruments are reflected in the earnings of our non-utility operations and may cause significant period-to-period volatility in earnings. The storage and transportation capacities utilized by WGL Midstream are not considered to be derivative instruments, and thus they are not recorded at fair value on our consolidated balance sheets. Managing Price Risk. WGL Energy Services enters into certain derivative contracts as part of managing the price risk associated with the sale and purchase of natural gas and electricity. WGL Energy Services designates a portion of these physical contracts related to the purchase of natural gas and electricity to serve our customers as "normal purchases and normal sales" and therefore, they are not subject to the fair value accounting requirements of ASC Topic 815. Derivative instruments not designated as "normal purchases and normal sales" are recorded at fair value on our consolidated balance sheets, and changes in the fair value of these derivative instruments are reflected in the earnings of our non-utility operations, which may cause significant period-to-period volatility in earnings. WGL Energy Services does not designate derivatives as hedges under ASC Topic 815. Managing Interest-Rate Risk . WGL utilizes derivative instruments that are designed to minimize the risk of interest-rate volatility associated with future debt issuances. WGL elected cash flow hedge accounting for its interest rate derivative instruments, which settled with the issuance of the related debt issuance in the first quarter of 2015. The effective portion of the gains and losses on the hedge were recorded within other comprehensive income and are being amortized over the life of the debt (through 2044). The amortization will be minimal for fiscal 2015. Consolidated Operations Reflected in the tables below is information for WGL as well as Washington Gas. The information for WGL includes derivative instruments for both utility and non-utility operations. At June 30, 2015 and September 30, 2014 , respectively, the absolute notional amounts of our derivatives were as follows: Absolute Notional Amounts of Open Positions on Derivative Instruments Derivative transactions WGL Holdings, Inc. Washington Gas June 30, 2015 Notional Amounts Natural Gas (In millions of therms) Asset Optimization 21,296.2 13,722.3 Retail sales 0.8 — Other risk-management activities 1,786.9 1,377.4 Electricity (In millions of kWhs) Retail sales 4,474.0 — Other risk-management activities 20,683.5 — September 30, 2014 Natural Gas (In millions of therms) Asset Optimization 20,593.3 13,740.9 Retail sales 44.7 — Other risk-management activities 1,641.3 1,398.2 Electricity (In millions of kWhs) Retail sales 3,831.4 — Other risk-management activities 16,734.1 — Warrants (In millions of shares) 4.6 — Interest Rate Swaps (In millions of dollars) 150.0 — The following tables present the balance sheet classification for all derivative instruments as of June 30, 2015 and September 30, 2014 . WGL Holdings, Inc. Balance Sheet Classification of Derivative Instruments (In millions) Derivative Instruments Not Designated as Hedging Instruments Derivative Instruments Designated as Hedging Instruments As of June 30, 2015 Gross Derivative Assets Gross Derivative Liabilities Gross Derivative Assets Gross Derivative Liabilities Netting of Collateral Total (a) Current Assets—Derivatives $ 14.5 $ (0.1 ) $ — $ — $ 1.3 $ 15.7 Deferred Charges and Other Assets—Derivatives 28.5 (0.2 ) — — — 28.3 Current Liabilities—Derivatives 23.9 (86.2 ) — — 3.5 (58.8 ) Deferred Credits—Derivatives 2.0 (362.0 ) — — 5.7 (354.3 ) Total $ 68.9 $ (448.5 ) $ — $ — $ 10.5 $ (369.1 ) As of September 30, 2014 Current Assets—Derivatives $ 20.8 $ (2.5 ) $ — $ — $ — $ 18.3 Deferred Charges and Other Assets—Derivatives 18.7 — — — — 18.7 Current Liabilities—Derivatives 15.4 (70.3 ) — (1.7 ) 8.0 (48.6 ) Deferred Credits—Derivatives 17.7 (316.4 ) — — 4.0 (294.7 ) Total $ 72.6 $ (389.2 ) $ — $ (1.7 ) $ 12.0 $ (306.3 ) Washington Gas Light Company Balance Sheet Classification of Derivative Instruments (b) (In millions) As of June 30, 2015 Gross Gross Netting of Total (a) Current Assets—Derivatives $ 5.9 $ — $ 1.3 $ 7.2 Deferred Charges and Other Assets—Derivatives 12.4 (0.1 ) — 12.3 Current Liabilities—Derivatives 7.8 (44.8 ) — (37.0 ) Deferred Credits—Derivatives 0.6 (293.5 ) — (292.9 ) Total $ 26.7 $ (338.4 ) $ 1.3 $ (310.4 ) As of September 30, 2014 Current Assets—Derivatives $ 3.9 $ — $ — $ 3.9 Deferred Charges and Other Assets—Derivatives 9.5 — — 9.5 Current Liabilities—Derivatives 8.6 (43.2 ) 0.7 (33.9 ) Deferred Credits—Derivatives 4.2 (265.2 ) 0.2 (260.8 ) Total $ 26.2 $ (308.4 ) $ 0.9 $ (281.3 ) (a) WGL has elected to offset the fair value of recognized derivative instruments against the right to reclaim or the obligation to return collateral for derivative instruments executed under the same master netting arrangement in accordance with ASC 815. All recognized derivative contracts and associated financial collateral subject to a master netting arrangement or similar that is eligible for offset under ASC 815 have been presented net in the balance sheet. (b) Washington Gas did not have any derivative instruments outstanding that were designated as hedging instruments at June 30, 2015 or September 30, 2014 . The following table presents all gains and losses associated with derivative instruments for the three and nine months ended June 30, 2015 and 2014 . Gains and Losses on Derivative Instruments (In millions) WGL Holdings, Inc. Washington Gas Three Months Ended June 30, 2015 2014 2015 2014 Recorded to income Operating revenues—non-utility $ (28.3 ) $ (21.3 ) $ — $ — Utility cost of gas (10.4 ) (2.0 ) (10.4 ) (2.0 ) Non-utility cost of energy-related sales 3.2 2.8 — — Other income-net — (0.6 ) — — Recorded to regulatory assets Gas costs (12.1 ) (12.5 ) (12.1 ) (12.5 ) Total $ (47.6 ) $ (33.6 ) $ (22.5 ) $ (14.5 ) Nine Months Ended June 30, 2015 2014 2015 2014 Recorded to income Operating revenues—non-utility $ 46.0 $ (105.6 ) $ — $ — Utility cost of gas (20.4 ) (125.7 ) (20.4 ) (125.7 ) Non-utility cost of energy-related sales (35.9 ) 46.7 — — Other income-net — (0.5 ) — — Interest expense (a) (0.5 ) — — — Recorded to regulatory assets Gas costs (36.0 ) (224.5 ) (36.0 ) (224.5 ) Other — 1.2 — 1.2 Recorded to other comprehensive income (b) (8.0 ) — — — Total $ (54.8 ) $ (408.4 ) $ (56.4 ) $ (349.0 ) (a) Represents $(0.4) million of ineffectiveness for our cash flow hedge and $(0.1) million of amortization of amounts previously recorded to Accumulated Other Comprehensive Income. (b) Represents the effective portion of our cash flow hedge of $(8.1) million less $(0.1) million of amortization that was reclassified to interest expense. Collateral WGL utilizes standardized master netting agreements, which facilitate the netting of cash flows into a single net exposure for a given counterparty. As part of these master netting agreements, cash, letters of credit and parental guarantees may be required to be posted or obtained from counterparties in order to mitigate credit risk related to both derivatives and non-derivative positions. Under WGL’s offsetting policy, collateral balances are offset against the related counterparties’ derivative positions to the extent the application would not result in the over-collateralization of those derivative positions on the balance sheet. At June 30, 2015 , Washington Gas, WGL Energy Services and WGL Midstream posted $6.5 million , $8.9 million and $9.9 million , respectively, of collateral deposits with counterparties that were not offset against open and settled derivative contracts. At September 30, 2014 , Washington Gas, WGL Energy Services and WGL Midstream posted $8.2 million , $5.7 million and $11.4 million , respectively, of collateral deposits with counterparties that were not offset against open and settled derivative contracts. At June 30, 2015 , Washington Gas, WGL Energy Services and WGL Midstream held $4.1 million , $0.1 million and $0.1 million , respectively of cash collateral representing an obligation to counterparties that was not offset against open and settled derivative contracts. At September 30, 2014 , Washington Gas held $2.5 million of cash collateral representing an obligation to counterparties that was not offset against open and settled derivative contracts. Any collateral posted that is not offset against open and settled derivative contracts is included in “Other prepayments” in the accompanying balance sheet. Collateral received and not offset against open and settled derivative contracts is included in “Customer deposits and advance payments” in the accompanying balance sheet. Certain derivative instruments of Washington Gas, WGL Energy Services and WGL Midstream contain contract provisions that require collateral to be posted if the credit rating of Washington Gas or WGL falls below certain levels or if counterparty exposure to WGL Energy Services or WGL Midstream exceeds a certain level. Due to counterparty exposure levels, at June 30, 2015 , WGL Energy Services posted $5.7 million of collateral related to its derivative liabilities that contained credit-related contingent features. At September 30, 2014 , WGL Energy Services posted $5.3 million of collateral related to such derivative liabilities. Washington Gas and WGL Midstream were not required to post any collateral related to their respective derivative liabilities that contained credit-related contingent features at June 30, 2015 or September 30, 2014 . The following table shows the aggregate fair value of all derivative instruments with credit-related contingent features that are in a liability position, as well as the maximum amount of collateral that would be required if the most intrusive credit-risk-related contingent features underlying these agreements were triggered on June 30, 2015 and September 30, 2014 , respectively. Potential Collateral Requirements for Derivative Liabilities with Credit-Risk-Contingent Features (In millions) WGL Holdings, Inc. Washington Gas June 30, 2015 Derivative liabilities with credit-risk-contingent features $ 54.4 $ 20.1 Maximum potential collateral requirements 46.6 20.0 September 30, 2014 Derivative liabilities with credit-risk-contingent features $ 28.8 $ 20.6 Maximum potential collateral requirements 16.5 16.1 Washington Gas, WGL Energy Services and WGL Midstream do not enter into derivative contracts for speculative purposes. Concentration of Credit Risk We are exposed to credit risk from derivative instruments with wholesale counterparties, which is represented by the fair value of these instruments at the reporting date. We actively monitor and work to minimize counterparty concentration risk through various practices. At June 30, 2015 , two counterparties represented over 10% of Washington Gas’ credit exposure to wholesale derivative counterparties for a total credit risk of $23.4 million ; two counterparties represented over 10% of WGL Energy Services’ credit exposure to wholesale counterparties for a total credit risk of $0.2 million ; and two counterparties represented over 10% of WGL Midstream’s credit exposure to wholesale counterparties for a total credit risk of $15.0 million . WEATHER-RELATED INSTRUMENTS Washington Gas did not use any weather-related instruments during the three and nine months ended June 30, 2015 and 2014 . WGL Energy Services utilizes weather-related instruments for managing the financial effects of weather risks. These instruments cover a portion of WGL Energy Services’ estimated revenue or energy-related cost exposure to variations in heating or cooling degree days. These contracts provide for payment to WGL Energy Services of a fixed-dollar amount for every degree day over or under specific levels during the calculation period depending upon the type of contract executed. For the three months ended June 30, 2015 and 2014 , WGL Energy Services recorded pre-tax losses of $0.5 million and $0.9 million , respectively, related to these contracts. For the nine months ended June 30, 2015 and 2014 , WGL Energy Services recorded pre-tax gains of $2.7 million and $4.5 million , respectively, related to these contracts.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 9. FAIR VALUE MEASUREMENTS Recurring Basis We measure the fair value of our financial assets and liabilities using a combination of the income and market approach in accordance with ASC Topic 820. These financial assets and liabilities primarily consist of derivatives recorded on our balance sheet under ASC Topic 815 and short-term investments, commercial paper and long-term debt outstanding required to be disclosed at fair value. Under ASC Topic 820, fair value is defined as the exit price, representing the amount that would be received in the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. To value our financial instruments, we use market data or assumptions that market participants would use, including assumptions about credit risk (both our own credit risk and the counterparty’s credit risk) and the risks inherent in the inputs to valuation. We enter into derivative contracts in the futures and over-the-counter (OTC) wholesale and retail markets. These markets are the principal markets for the respective wholesale and retail contracts. Our relevant market participants are our existing counterparties and others who have participated in energy transactions at our delivery points. These participants have access to the same market data as WGL. We value our derivative contracts based on an “in-exchange” premise, and valuations are generally based on pricing service data or indicative broker quotes depending on the market location. We measure the net credit exposure at the counterparty level where the right to set-off exists. The net exposure is determined using the mark-to-market exposure adjusted for collateral, letters of credit and parent guarantees. We use published default rates from Standard & Poor’s Ratings Services and Moody’s Investors Service as inputs for determining credit adjustments. ASC Topic 820 establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The three levels of the fair value hierarchy under ASC Topic 820 are described below: Level 1. Level 1 of the fair value hierarchy consists of assets or liabilities that are valued using observable inputs based upon unadjusted quoted prices in active markets for identical assets or liabilities at the reporting date. Level 1 assets and liabilities primarily include exchange traded derivatives and securities. WGL did not have any Level 1 derivatives at June 30, 2015 or September 30, 2014 . Level 2. Level 2 of the fair value hierarchy consists of assets or liabilities that are valued using directly or indirectly observable inputs either corroborated with market data or based on exchange traded market data. Level 2 includes fair values based on industry-standard valuation techniques that consider various assumptions: (i) quoted forward prices, including the use of mid-market pricing within a bid/ask spread; (ii) discount rates; (iii) implied volatility and (iv) other economic factors. Substantially all of these assumptions are observable throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the relevant market. At June 30, 2015 and September 30, 2014 , Level 2 financial assets and liabilities included energy-related derivatives such as financial contracts, options and physical forward contracts for deliveries at active market locations. Level 3. Level 3 of the fair value hierarchy consists of assets or liabilities that are valued using significant unobservable inputs at the reporting date. These unobservable assumptions reflect our assumptions about estimates that market participants would use in pricing the asset or liability, including natural gas basis prices, annualized volatilities of natural gas prices, and electricity congestion prices. A significant change to any one of these inputs in isolation could result in a significant upward or downward fluctuation in the fair value measurement. These inputs may be used with industry standard valuation methodologies that result in our best estimate of fair value for the assets or liabilities at the reporting date. Our Risk Analysis and Mitigation (RA&M) Group determines the valuation policies and procedures. The RA&M Group reports to WGL’s Chief Financial Officer. In accordance with WGL’s valuation policy, we may utilize a variety of valuation methodologies to determine the fair value of Level 3 derivative contracts, including internally developed valuation inputs and pricing models. The prices used in our valuations are corroborated using multiple pricing sources, and we periodically conduct assessments to determine whether each valuation model is appropriate for its intended purpose. The RA&M Group also evaluates changes in fair value measurements on a daily basis. At June 30, 2015 and September 30, 2014 , Level 3 derivative assets and liabilities included: (i) physical contracts valued at illiquid market locations with no observable market data; (ii) long-dated positions where observable pricing is not available over the life of the contract; (iii) contracts valued using historical spot price volatility assumptions and (iv) valuations using indicative broker quotes for inactive market locations. The following tables set forth financial instruments recorded at fair value as of June 30, 2015 and September 30, 2014 , respectively. A financial instrument’s classification within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy. WGL Holdings, Inc. Fair Value Measurements Under the Fair Value Hierarchy (In millions) Level 1 Level 2 Level 3 Total At June 30, 2015 Assets Natural gas related derivatives $ — $ 22.4 $ 22.4 $ 44.8 Electricity related derivatives — 2.1 22.0 24.1 Total Assets $ — $ 24.5 $ 44.4 $ 68.9 Liabilities Natural gas related derivatives $ — $ (41.0 ) $ (373.4 ) $ (414.4 ) Electricity related derivatives — (3.3 ) (30.8 ) (34.1 ) Total Liabilities $ — $ (44.3 ) $ (404.2 ) $ (448.5 ) At September 30, 2014 Assets Natural gas related derivatives $ — $ 22.7 $ 33.7 $ 56.4 Electricity related derivatives — 0.3 15.9 16.2 Total Assets $ — $ 23.0 $ 49.6 $ 72.6 Liabilities Natural gas related derivatives $ — $ (39.8 ) $ (328.4 ) $ (368.2 ) Electricity related derivatives — (0.1 ) (20.9 ) (21.0 ) Interest rate derivatives — (1.7 ) — (1.7 ) Total Liabilities $ — $ (41.6 ) $ (349.3 ) $ (390.9 ) Washington Gas Light Company Fair Value Measurements Under the Fair Value Hierarchy (In millions) Level 1 Level 2 Level 3 Total At June 30, 2015 Assets Natural gas related derivatives $ — $ 14.8 $ 11.9 $ 26.7 Total Assets $ — $ 14.8 $ 11.9 $ 26.7 Liabilities Natural gas related derivatives $ — $ (19.3 ) $ (319.1 ) $ (338.4 ) Total Liabilities $ — $ (19.3 ) $ (319.1 ) $ (338.4 ) At September 30, 2014 Assets Natural gas related derivatives $ — $ 13.5 $ 12.7 $ 26.2 Total Assets $ — $ 13.5 $ 12.7 $ 26.2 Liabilities Natural gas related derivatives $ — $ (25.1 ) $ (283.3 ) $ (308.4 ) Total Liabilities $ — $ (25.1 ) $ (283.3 ) $ (308.4 ) The following table includes quantitative information about the significant unobservable inputs used in the fair value measurement of our Level 3 financial instruments and the respective fair values of the net derivative asset and liability positions, by contract type, as of June 30, 2015 and September 30, 2014 . Quantitative Information about Level 3 Fair Value Measurements (In millions) Net Fair Value Valuation Techniques Unobservable Inputs Range WGL Holdings, Inc. Natural gas related derivatives $(351.0) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($1.629) - $4.920 Option Model Natural Gas Basis Price (per dekatherm) ($0.153) - ($0.090) Annualized Volatility of Spot Market Natural Gas 30.5% to 40.2% Electricity related derivatives $(8.8) Discounted Cash Flow Electricity Congestion Price (per megawatt hour) ($3.965) - $83.900 Washington Gas Light Company Natural gas related derivatives $(307.2) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($1.629) - $4.920 Net Fair Value WGL Holdings, Inc. Natural gas related derivatives $(294.7) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($2.101) - $6.154 Option Model Natural Gas Basis Price (per dekatherm) ($1.675) - $6.154 Annualized Volatility of Spot Market Natural Gas 30.9% - 589.6% Electricity related derivatives $(5.0) Discounted Cash Flow Electricity Congestion Price (per megawatt hour) ($2.85) - $90.95 Washington Gas Light Company Natural gas related derivatives $(270.6) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($2.101) - $6.154 The following tables are a summary of the changes in the fair value of our derivative instruments that are measured at net fair value on a recurring basis in accordance with ASC Topic 820 using significant Level 3 inputs during the three and nine months ended June 30, 2015 and 2014 , respectively. WGL Holdings, Inc. Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Balance at April 1, 2015 $ (319.6 ) $ (10.5 ) $ — $ (330.1 ) Realized and unrealized gains (losses) Recorded to income (33.6 ) (4.8 ) — (38.4 ) Recorded to regulatory assets—gas costs (7.7 ) — — (7.7 ) Transfers out of Level 3 3.9 — — 3.9 Purchases — 3.9 — 3.9 Settlements 6.0 2.6 — 8.6 Balance at June 30, 2015 $ (351.0 ) $ (8.8 ) $ — $ (359.8 ) Three Months Ended June 30, 2014 Balance at April 1, 2014 $ (432.3 ) $ (2.2 ) $ 1.2 $ (433.3 ) Realized and unrealized gains (losses) Recorded to income (19.0 ) (2.3 ) (0.6 ) (21.9 ) Recorded to regulatory assets—gas costs (15.9 ) — — (15.9 ) Transfers out of Level 3 1.7 — — 1.7 Purchases — 2.3 — 2.3 Settlements 4.9 0.5 — 5.4 Balance at June 30, 2014 $ (460.6 ) $ (1.7 ) $ 0.6 $ (461.7 ) Nine Months Ended June 30, 2015 Balance at October 1, 2014 $ (294.7 ) $ (5.0 ) $ — $ (299.7 ) Realized and unrealized gains (losses) Recorded to income (51.0 ) (15.3 ) — (66.3 ) Recorded to regulatory assets—gas costs (48.0 ) — — (48.0 ) Transfers into Level 3 5.4 — — 5.4 Transfers out of Level 3 3.6 — — 3.6 Purchases — 7.3 — 7.3 Settlements 33.7 4.2 — 37.9 Balance at June 30, 2015 $ (351.0 ) $ (8.8 ) $ — $ (359.8 ) Nine Months Ended June 30, 2014 Balance at October 1, 2013 $ (155.2 ) $ 2.4 $ 1.1 $ (151.7 ) Realized and unrealized gains (losses) Recorded to income (151.6 ) 1.0 (0.5 ) (151.1 ) Recorded to regulatory assets—gas costs (198.7 ) — — (198.7 ) Transfers out of Level 3 1.7 — — 1.7 Purchases — 3.7 — 3.7 Settlements 43.2 (8.8 ) — 34.4 Balance at June 30, 2014 $ (460.6 ) $ (1.7 ) $ 0.6 $ (461.7 ) Washington Gas Light Company Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Balance at April 1, 2015 $ (299.8 ) Realized and unrealized gains (losses) Recorded to income (7.6 ) Recorded to regulatory assets—gas costs (7.7 ) Transfers out of Level 3 2.8 Settlements 5.1 Balance at June 30, 2015 $ (307.2 ) Three Months Ended June 30, 2014 Balance at April 1, 2014 $ (382.6 ) Realized and unrealized gains (losses) Recorded to income (4.5 ) Recorded to regulatory assets—gas costs (15.9 ) Transfers out of Level 3 1.7 Settlements 4.4 Balance at June 30, 2014 $ (396.9 ) Nine Months Ended June 30, 2015 Balance at October 1, 2014 $ (270.6 ) Realized and unrealized gains (losses) Recorded to income (30.3 ) Recorded to regulatory assets—gas costs (48.0 ) Transfers into Level 3 5.4 Transfers out of Level 3 2.5 Settlements 33.8 Balance at June 30, 2015 $ (307.2 ) Nine Months Ended June 30, 2014 Balance at October 1, 2013 $ (133.6 ) Realized and unrealized gains (losses) Recorded to income (109.7 ) Recorded to regulatory assets—gas costs (198.7 ) Transfers out of Level 3 1.7 Settlements 43.4 Balance at June 30, 2014 $ (396.9 ) Transfers between different levels of the fair value hierarchy may occur based on the level of observable inputs used to value the instruments from period to period. It is our policy to show both transfers into and out of the different levels of the fair value hierarchy at the fair value as of the beginning of the period. Transfers out of Level 3 during the three and nine months ended June 30, 2015 and 2014 were due to an increase in valuations using observable market inputs. Transfers into Level 3 during the nine months ended June 30, 2015 were due to an increase in unobservable market inputs used in valuations. The table below sets forth the line items on the statements of income to which amounts are recorded for the three and nine months ended June 30, 2015 and 2014, respectively, related to fair value measurements using significant Level 3 inputs. WGL Holdings, Inc. Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Operating revenues—non-utility $ (22.3 ) $ (3.0 ) $ — $ (25.3 ) Utility cost of gas (7.6 ) — — (7.6 ) Non-utility cost of energy-related sales (3.7 ) (1.8 ) — (5.5 ) Total $ (33.6 ) $ (4.8 ) $ — $ (38.4 ) Three Months Ended June 30, 2014 Operating revenues—non-utility $ (14.3 ) $ (5.6 ) $ — $ (19.9 ) Utility cost of gas (4.5 ) — — (4.5 ) Other income-net — — (0.6 ) (0.6 ) Non-utility cost of energy-related sales (0.2 ) 3.3 — 3.1 Total $ (19.0 ) $ (2.3 ) $ (0.6 ) $ (21.9 ) Nine Months Ended June 30, 2015 Operating revenues—non-utility $ (20.7 ) $ 21.0 $ — $ 0.3 Utility cost of gas (30.3 ) — — (30.3 ) Non-utility cost of energy-related sales — (36.3 ) — (36.3 ) Total $ (51.0 ) $ (15.3 ) $ — $ (66.3 ) Nine Months Ended June 30, 2014 Operating revenues—non-utility $ (40.6 ) $ (30.1 ) $ — $ (70.7 ) Utility cost of gas (109.7 ) — — (109.7 ) Other income-net — — (0.5 ) (0.5 ) Non-utility cost of energy-related sales (1.3 ) 31.1 — 29.8 Total $ (151.6 ) $ 1.0 $ (0.5 ) $ (151.1 ) Washington Gas Light Company Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Utility cost of gas $ (7.6 ) Total $ (7.6 ) Three Months Ended June 30, 2014 Utility cost of gas $ (4.5 ) Total $ (4.5 ) Nine Months Ended June 30, 2015 Utility cost of gas $ (30.3 ) Total $ (30.3 ) Nine Months Ended June 30, 2014 Utility cost of gas $ (109.7 ) Total $ (109.7 ) Unrealized gains (losses) attributable to derivative assets and liabilities measured using significant Level 3 inputs were recorded as follows, for the three and nine months ended June 30, 2015 and 2014 , respectively. WGL Holdings, Inc. Unrealized Gains (Losses) Recorded for Level 3 Measurements (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Recorded to income Operating revenues—non-utility $ (21.3 ) $ 0.8 $ — $ (20.5 ) Utility cost of gas (1.8 ) — — (1.8 ) Non-utility cost of energy-related sales (5.6 ) 2.5 — (3.1 ) Recorded to regulatory assets—gas costs (9.2 ) — — (9.2 ) Total $ (37.9 ) $ 3.3 $ — $ (34.6 ) Three Months Ended June 30, 2014 Recorded to income Operating revenues—non-utility $ (13.9 ) $ (5.8 ) $ — $ (19.7 ) Utility cost of gas (6.0 ) — — (6.0 ) Non-utility cost of energy-related sales (0.1 ) 5.3 — 5.2 Other income-net — — (0.6 ) (0.6 ) Recorded to regulatory assets—gas costs (17.6 ) — — (17.6 ) Total $ (37.6 ) $ (0.5 ) $ (0.6 ) $ (38.7 ) Nine Months Ended June 30, 2015 Recorded to income Operating revenues—non-utility $ (17.6 ) $ 21.7 $ — $ 4.1 Utility cost of gas (23.1 ) — — (23.1 ) Non-utility cost of energy-related sales (1.7 ) (31.5 ) — (33.2 ) Recorded to regulatory assets—gas costs (38.1 ) — — (38.1 ) Total $ (80.5 ) $ (9.8 ) $ — $ (90.3 ) Nine Months Ended June 30, 2014 Recorded to income Operating revenues—non-utility $ (44.6 ) $ (39.3 ) $ — $ (83.9 ) Utility cost of gas (100.4 ) — — (100.4 ) Non-utility cost of energy-related sales 3.3 35.8 — 39.1 Other income-net — — (0.5 ) (0.5 ) Recorded to regulatory assets—gas costs (190.7 ) — — (190.7 ) Total $ (332.4 ) $ (3.5 ) $ (0.5 ) $ (336.4 ) Washington Gas Light Company Unrealized Gains (Losses) Recorded for Level 3 Measurements (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Recorded to income - utility cost of gas $ (1.8 ) Recorded to regulatory assets—gas costs (9.2 ) Total $ (11.0 ) Three Months Ended June 30, 2014 Recorded to income - utility cost of gas $ (6.0 ) Recorded to regulatory assets—gas costs (17.6 ) Total $ (23.6 ) Nine Months Ended June 30, 2015 Recorded to income - utility cost of gas $ (23.1 ) Recorded to regulatory assets—gas costs (38.1 ) Total $ (61.2 ) Nine Months Ended June 30, 2014 Recorded to income - utility cost of gas $ (100.4 ) Recorded to regulatory assets—gas costs (190.7 ) Total $ (291.1 ) The following table presents the carrying amounts and estimated fair values of our financial instruments at June 30, 2015 and September 30, 2014 . WGL Holdings, Inc. Fair Value of Financial Instruments June 30, 2015 September 30, 2014 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value Money market funds (a) $ 74.6 $ 74.6 $ 9.7 $ 9.7 Other short-term investments (a) $ 1.0 $ 1.0 $ — $ — Commercial paper (b) $ 156.0 $ 156.0 $ 453.5 $ 453.5 Long-term debt (c) $ 950.5 $ 1,033.5 $ 679.2 $ 809.3 Washington Gas Light Company Fair Value of Financial Instruments June 30, 2015 September 30, 2014 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value Money market funds (a) $ 70.4 $ 70.4 $ 4.3 $ 4.3 Other short-term investments (a) $ 1.0 $ 1.0 $ — $ — Commercial paper (b) $ — $ — $ 89.0 $ 89.0 Long-term debt (c) $ 702.2 $ 795.9 $ 679.2 $ 809.3 (a) Balance is located in cash and cash equivalents in the accompanying balance sheets. These amounts may be offset by outstanding checks. (b) Balance is located in notes payable in the accompanying balance sheets. (c) Less current maturities and unamortized discounts. Our money market funds are Level 1 valuations and their carrying amount approximates fair value. Other short-term investments are primarily overnight investment accounts; therefore, their carrying amount approximates fair value based on Level 2 inputs. The maturity of our commercial paper outstanding at both June 30, 2015 and September 30, 2014 is under 30 days. Due to the short term nature of these notes, the carrying cost of our commercial paper approximates fair value using Level 2 inputs. Neither WGL’s nor Washington Gas’ long-term debt is actively traded. The fair value of long-term debt was estimated based on the quoted market prices of the U.S. Treasury issues having a similar term to maturity, adjusted for the credit quality of the debt issuer, WGL or Washington Gas. Our long-term debt fair value measurement is classified as Level 3. Non Recurring Basis During the nine months ended June 30, 2015 , Washington Gas Resources recorded an impairment charge of its investment in ASDHI to its fair value using the income approach. The amount of the impairment was equivalent to the amount of the carrying value of $5.6 million and was due to management’s assumption of the current valuation and expected return from the investment. The fair value of this investment was a Level 3 measurement.

Operating Segment Reporting

Operating Segment Reporting	9 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Operating Segment Reporting	NOTE 10. OPERATING SEGMENT REPORTING We have four reportable operating segments: regulated utility, retail energy-marketing, commercial energy systems and midstream energy services. The division of these segments into separate revenue generating components is based upon regulation, products and services. Our chief operating decision maker is our Chief Executive Officer. During the first quarter of 2015, our chief operating decision maker began evaluating segment performance based on Earnings Before Interest and Taxes (EBIT). EBIT is defined as earnings before interest and taxes from continuing operations. Items we do not include in EBIT are interest expense, intercompany financing activity, dividends on Washington Gas preferred stock, and income taxes. EBIT includes transactions between reportable segments. We also evaluate our operating segments based on other relevant factors, such as penetration into their respective markets and return on equity. Our four segments are summarized below. • Regulated Utility – The regulated utility segment is our core business. It consists of Washington Gas and Hampshire. Washington Gas provides regulated gas distribution services (including the sale and delivery of natural gas) to end use customers and natural gas transportation services to an unaffiliated natural gas distribution company in West Virginia under a Federal Energy Regulatory Commission (FERC) approved interstate transportation service operating agreement. Hampshire provides regulated interstate natural gas storage services to Washington Gas under a FERC approved interstate storage service tariff. • Retail Energy-Marketing – The retail energy-marketing segment consists of WGL Energy Services, which sells natural gas and electricity directly to retail customers in competition with regulated utilities and unregulated gas and electricity marketers. • Commercial Energy Systems – The commercial energy systems segment consists of WGL Energy Systems which provides clean and energy efficient solutions including commercial solar, energy efficiency and combined heat and power projects and other distributed generation solutions to government and commercial clients. In addition, this segment comprises the operations of WGSW, a holding company formed to invest in alternative energy assets. • Midstream Energy Services – The midstream energy services segment consists of WGL Midstream, which engages in acquiring, investing in, managing and optimizing natural gas storage and transportation assets. Activities and transactions that are not significant enough on a stand-alone basis to warrant treatment as an operating segment, and that do not fit into one of our four operating segments, are aggregated as “Other Activities” in the Operating Segment Financial Information presented below. Administrative and business development activity costs associated with WGL and Washington Gas Resources are included in “Other Activities”. The following tables present operating segment information for the three and nine months ended June 30, 2015 and 2014 . Operating Segment Financial Information (In thousands) Operating Revenues (a) Depreciation and Amortization Equity in Earnings of Unconsolidated Affiliates EBIT Total Assets Capital Expenditures Equity Method Investments Three Months Ended June 30, 2015 Regulated utility $ 190,345 $ 27,740 $ — $ (6,262 ) $ 4,113,166 $ 75,413 $ — Retail energy-marketing 268,249 151 — 16,654 464,086 — — Commercial energy systems 14,674 2,787 544 3,750 613,124 27,271 64,323 Midstream energy services (25,801 ) 31 718 (26,607 ) 203,591 85 56,967 Other activities — — — (970 ) 106,861 — — Eliminations (b) (6,294 ) (13 ) — (541 ) (492,363 ) — — Total consolidated $ 441,173 $ 30,696 $ 1,262 $ (13,976 ) $ 5,008,465 $ 102,769 $ 121,290 Three Months Ended June 30, 2014 Regulated utility $ 197,752 $ 25,840 $ — $ 4,456 $ 3,809,747 $ 76,073 $ — Retail energy-marketing 275,339 204 — 1,286 387,990 5 — Commercial energy systems 14,260 1,611 733 5,012 459,509 18,171 68,309 Midstream energy services (15,869 ) 31 85 (16,806 ) 181,880 — 22,426 Other activities — — — (2,391 ) 224,220 — 413 Eliminations (b) (3,982 ) (64 ) — (532 ) (502,662 ) — — Total consolidated $ 467,500 $ 27,622 $ 818 $ (8,975 ) $ 4,560,684 $ 94,249 $ 91,148 Nine Months Ended June 30, 2015 Regulated utility $ 1,193,232 $ 81,958 $ — $ 238,645 $ 4,113,166 $ 235,707 $ — Retail energy-marketing 1,003,339 470 — 39,185 464,086 5 — Commercial energy systems 35,745 7,693 1,623 4,731 613,124 81,246 64,323 Midstream energy services (17,997 ) 93 1,865 (23,343 ) 203,591 85 56,967 Other activities — — 750 (8,915 ) 106,861 — — Eliminations (b) (22,176 ) (55 ) — (592 ) (492,363 ) — — Total consolidated $ 2,192,143 $ 90,159 $ 4,238 $ 249,711 $ 5,008,465 $ 317,043 $ 121,290 Nine Months Ended June 30, 2014 Regulated utility $ 1,304,975 $ 76,945 $ — $ 158,444 $ 3,809,747 $ 181,821 $ — Retail energy-marketing 1,035,711 558 — 5,186 387,990 93 — Commercial energy systems 27,013 4,255 1,496 5,961 459,509 59,536 68,309 Midstream energy services (21,938 ) 93 355 (29,410 ) 181,880 — 22,426 Other activities — — — (10,227 ) 224,220 — 413 Eliminations (b) (23,714 ) (335 ) — 110 (502,662 ) — — Total consolidated $ 2,322,047 $ 81,516 $ 1,851 $ 130,064 $ 4,560,684 $ 241,450 $ 91,148 (a) Operating revenues are reported gross of revenue taxes. Revenue taxes of both the regulated utility and the retail energy-marketing segments include gross receipt taxes. Revenue taxes of the regulated utility segment also include public service commission fees, franchise fees and energy taxes. Operating revenue amounts in the “Eliminations” row represent total intersegment revenues associated with sales from the regulated utility segment to the retail energy-marketing segment. Midstream Energy Services’ cost of energy related sales is netted with its gross revenues. (b) Intersegment eliminations include any mark-to market valuations associated with trading activities between WGL Midstream and WGL Energy Services, intercompany loans and a timing difference between Commercial Energy Systems’ recognition of revenue for the sale of Renewable Energy Credits (RECs) to Retail Energy-Marketing and Retail Energy-Marketing’s recognition of the associated expense. Retail Energy-Marketing has recorded a portion of the REC’s purchased as inventory to be used in future periods at which time they will be expensed. The following table provides a reconciliation from EBIT to net income applicable to common stock. Three Months Ended June 30, Nine Months Ended June 30, (In thousands) 2015 2014 2015 2014 Total consolidated EBIT $ (13,976 ) $ (8,975 ) $ 249,711 $ 130,064 Interest expense 13,140 9,503 38,704 28,020 Income (loss) before income taxes (27,116 ) (18,478 ) 211,007 102,044 Income tax expense (benefit) (11,756 ) (6,868 ) 80,364 33,152 Net income (loss) (15,360 ) (11,610 ) 130,643 68,892 Dividends on Washington Gas Light Company preferred stock 330 330 990 990 Net income (loss) applicable to common stock $ (15,690 ) $ (11,940 ) $ 129,653 $ 67,902

Other Investments

Other Investments	9 Months Ended
	Jun. 30, 2015
Other Investments [Abstract]
Other Investments	NOTE 11. OTHER INVESTMENTS When determining how to account for our interests in other legal entities, WGL first evaluates if we are required to apply the variable interest entity (VIE) model to the entity, otherwise the entity is evaluated under the voting interest model. Under the VIE model, we have a controlling financial interest in a VIE (i.e. are the primary beneficiary) when we have current or potential rights that give us the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance combined with a variable interest that gives us the right to receive potentially significant benefits or the obligation to absorb potentially significant losses. When changes occur to the design of an entity, we reconsider whether it is subject to the VIE model. We continuously evaluate whether we have a controlling financial interest in a VIE. Under the voting interest model, we generally have a controlling financial interest in an entity where we currently hold, directly or indirectly, more than 50% of the voting rights or where we exercise control through substantive participating rights. However, we consider substantive rights held by other partners in determining if we hold a controlling financial interest, and in some cases, despite owning more than 50% of the common stock of an investee, an evaluation of our rights results in the determination that we do not have a controlling financial interest. We reevaluate whether we have a controlling financial interest in these entities when our voting or substantive participating rights change. Unconsolidated affiliates are unconsolidated VIEs and other entities evaluated under the voting interest method in which we do not have a controlling financial interest, but over which we have varying degrees of influence. Where we have significant influence, the affiliates are accounted for as equity method investments. Where we do not have significant influence, the affiliates are accounted for under the cost method. Investments in, and advances to, affiliated companies are presented on a one-line basis in the caption “Investments in unconsolidated affiliates” on our Consolidated Balance Sheet. WGL uses the Hypothetical Liquidation at Book Value (HLBV) methodology for certain equity method investments when the capital structure of the equity investment results in different liquidation rights and priorities than what is reflected by the underlying percentage ownership interests as defined by an equity investment agreement. For investments accounted for under the HLBV method, simply applying the percentage ownership interest to GAAP net income in order to determine earnings or losses does not accurately represent the income allocation and cash flow distributions that will ultimately be received by the investors. The equity investment agreements for ASD Solar, LP (ASD), Meade Pipeline Co LLC (Meade) and Mountain Valley Pipeline, LLC (Mountain Valley) have liquidation rights and priorities that are sufficiently different from the ownership percentages that the HLBV method was deemed appropriate. The calculation may vary in its complexity depending on the capital structure and the tax considerations for the investments. WGL applies HLBV using a balance sheet approach. A calculation is prepared at each balance sheet date to determine the amount that WGL would receive if an equity investment entity were to liquidate all of its assets (as valued in accordance with GAAP) and distribute that cash to the investors based on the contractually defined liquidation priorities. The difference between the calculated liquidation distribution amounts at the beginning and the end of the reporting period is WGL’s share of the earnings or losses from the equity investment for the period. Variable Interest Entities WGL has a variable interest in four investments that qualify as VIEs: • Meade, • SunEdison, • Nextility and • ASD. WGL previously had a variable interest in Crab Run; however, this investment was sold during the nine months ended June 30, 2015 . Accordingly, during the nine months ended June 30, 2015 , the carrying amount of the investment was removed and WGL recognized a gain of $0.7 million , which was recorded in "Equity in earnings of unconsolidated affiliates" on WGL's statements of income. WGL and its subsidiaries are not the primary beneficiary for any of the above VIEs, therefore we have not consolidated any of the VIE entities. At June 30, 2015 , the nature of WGL’s involvement with these investments lacks the characteristics of a controlling financial interest. WGL does not have control over any of the VIEs’ activities that are economically significant to the VIEs. In addition, WGL does not have the obligation to absorb expected losses or the right to receive expected gains that could be significant to the VIE. Meade In 2014, WGL through its subsidiary, WGL Midstream, entered into a limited liability company agreement and formed Meade, a Delaware limited liability company with COG Holdings LLC, Vega Midstream MPC LLC and River Road Interests LLC. Meade was formed to partner with Transcontinental Gas Pipeline Company, LLC (Williams) to invest in a regulated pipeline project called Central Penn Pipeline (Central Penn). The Central Penn will be an approximately 177 -mile pipeline originating in Susquehanna County, Pennsylvania and extending to Lancaster County, Pennsylvania that will have the capacity to transport and deliver up to approximately 1.7 million dekatherms per day of natural gas. WGL Midstream plans to invest an estimated $412.0 million for a 55% interest in Meade. WGL Midstream joins COG Holdings LLC ( 20% share), Vega Midstream MPC LLC ( 15% share) and River Road Interests LLC ( 10% share) in Meade. Meade is accounted for under the HLBV equity method of accounting, and any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGL’s investment balance. At June 30, 2015 and September 30, 2014 , WGL Midstream held a $21.7 million and $5.8 million , respectively, equity method investment in Meade. Our maximum financial exposure includes contributions and guarantees on behalf of WGL Midstream. Our maximum exposure to loss at June 30, 2015 was $59.4 million , which represents the minimum funding requirements owed to Williams under the Construction and Ownership Agreement should Meade terminate its agreement with Williams early. SunEdison/Nextility WGSW is party to two agreements to fund residential and commercial retail solar energy installations with two separate, privately held companies. WGSW has a master purchase agreement and master lease agreement with SunEdison, Inc. (SunEdison), and Nextility, Inc. (Nextility) for sale/leaseback arrangements for residential and commercial solar systems. Our agreements with SunEdison and Nextility are accounted for as direct financing leases. WGSW records associated interest in the financing leases in “Other income (expenses)-net” line in the accompanying Consolidated Statement of Income. WGSW held a $29.1 million and $19.9 million combined investment in direct financing leases at June 30, 2015 and September 30, 2014 , respectively, of which $3.3 million and $1.7 million are current receivables recorded in “Accounts Receivable” in the accompanying Consolidated Balance Sheets at June 30, 2015 and September 30, 2014 , respectively. Minimum future lease payments receivable under direct financing leases over the next five fiscal years and thereafter are as follows: Minimum Payments Receivable for Direct Financing Leases (In millions) Remainder of 2015 $ 2.4 2016 2.5 2017 2.4 2018 2.3 2019 2.2 Thereafter 22.6 Total $ 34.4 Minimum payments receivable exclude $7.7 million of residual values and $2.6 million in tax credits. Associated with these investments, WGSW holds $15.6 million of unearned income on its balance sheet. The initial direct costs (incurred in FY 2012) associated with these investments was $0.7 million . Our maximum financial exposure from solar agreements is limited to WGSW's lease payment receivables and investment contributions made to these companies. All additional future committed contributions are contingent on the projects meeting required criteria. Our exposure is offset by the owned physical assets received as part of the transaction and the quick economic return for the investment through the investment tax credit/treasury grant proceeds and accelerated depreciation. ASD In addition to SunEdison and Nextility, WGSW is also a limited partner in ASD, a limited partnership formed to own and operate a portfolio of residential solar projects, primarily rooftop photovoltaic power generation systems. As a limited partner, WGSW provided funding to the partnership but does not have power to direct the activities that most significantly affect the operations and economic performance of the entity. In January 2014, the funding commitment period expired for the partnership. WGSW’s maximum financial exposure is limited to its contributions made to the partnership. Our investment in ASD is accounted for under the HLBV equity method of accounting; any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGSW’s investment balance. At June 30, 2015 and September 30, 2014 , WGSW held a $64.3 million and $66.8 million , respectively, equity method investment in ASD. ASD is consolidated by its general partner, Solar Direct LLC. Solar Direct LLC is a wholly owned subsidiary of American Solar Direct Inc. (ASDI). At June 30, 2015 , the carrying amount of WGSW’s investment in ASD exceeded the amount of the underlying equity in net assets by $35.9 million due to WGSW recording additions to its investment in ASD’s net assets at fair value of contributions in accordance with GAAP. This basis difference is being amortized over the life of the assets. Non-VIE Investments ASDHI At September 30, 2014 , Washington Gas Resources held a $5.6 million investment in American Solar Direct Holdings Inc. (ASDHI) consisting of warrants and preferred stock. During the nine months ended June 30, 2015 , Washington Gas Resources impaired its entire investment in ASDHI by its carrying value of $5.6 million based on management’s assumption of the current valuation and expected return from the investment. Constitution In 2013, WGL Midstream invested in Constitution Pipeline Company, LLC (Constitution). WGL Midstream will invest an estimated aggregate amount of $79.0 million in the project for a 10% share in the pipeline venture over the term of the agreement. At June 30, 2015 , WGL Midstream had invested $26.4 million in Constitution. Other investors in the project include Williams Partners L.P. ( 41% share), Cabot Oil and Gas Corporation ( 25% share) and Piedmont Natural Gas ( 24% share) in the project. This natural gas pipeline venture will transport natural gas from the Marcellus region in northern Pennsylvania to major northeastern markets. Constitution is accounted for under the equity method of accounting; any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGL’s investment balance. The equity method is considered appropriate because Constitution is an LLC with specific ownership accounts and ownership between five and fifty percent resulting in WGL Midstream maintaining a more than minor influence over the partnership operating and financing policies. WGL Midstream held a $29.5 million equity method investment in Constitution at June 30, 2015 . At June 30, 2015 , the maximum financial exposure is equivalent to total capital contributions made in Constitution on behalf of WGL Midstream, which was $26.4 million . Mountain Valley Pipeline In March 2015, WGL Midstream acquired a 7% equity interest in Mountain Valley Pipeline, LLC (Mountain Valley). The proposed pipeline to be developed, constructed, owned and operated by Mountain Valley, will transport approximately 2.0 million dekatherms of natural gas per day from a new interconnect with EQT Corporation's Equitrans system, near the MarkWest Mobley plant in Smithfield, West Virginia to Transcontinental Gas Pipeline Company LLC's Station 165 in Pittsylvania County, Virginia. WGL Midstream expects to invest, in scheduled capital contributions through the in-service date of the pipeline, its pro rata share (based on its 7% equity interest) of project costs, an estimated aggregate amount of approximately $230 to $245 million . WGL Midstream held a $5.9 million equity method investment in Mountain Valley at June 30, 2015 . Our maximum financial exposure includes guarantees on behalf of WGL Midstream and another partner in the venture. WGL's maximum exposure to loss due to the provided guarantees was $20.0 million at June 30, 2015 which represents a $14.0 million minimum funding requirement for WGL Midstream and the guarantee on behalf of one of the other partners. In addition, WGL Midstream entered into an agreement to finance future capital commitments of one of the other partners in the venture for an estimated aggregate amount of approximately $96 to $105 million , which represents the estimated total funding requirements for that partner's 3% ownership interest in the joint venture, inclusive of the minimum funding requirement. WGL Midstream has provided funding of $2.5 million as of June 30, 2015 related to this agreement. The balance sheet location of the investments discussed in this footnote at June 30, 2015 and September 30, 2014 are as follows: WGL Holdings, Inc. Balance Sheet Location of Other Investments As of June 30, 2015 (in millions) VIEs Non-VIEs Total Assets Investments in unconsolidated affiliates $ 85.9 $ 35.4 $ 121.3 Investments in direct financing leases, capital leases 25.8 — 25.8 Accounts receivable 3.3 2.5 (a) 5.8 Total assets $ 115.0 $ 37.9 $ 152.9 As of September 30, 2014 (in millions) Assets Investments in unconsolidated affiliates $ 72.6 $ 27.9 $ 100.5 Investments in direct financing leases, capital leases 18.2 — 18.2 Accounts receivable 1.7 — 1.7 Total assets $ 92.5 $ 27.9 $ 120.4 (a) Represents the financing provided to another partner in Mountain Valley to fund its capital commitment. Acquired ownership interest represents the collateral for repayment of the financing. The income statement location of the investments discussed in this footnote for the three and nine months ended June 30, 2015 and 2014 are as follows: WGL Holdings, Inc. Income Statement Location of Other Investments (In millions) VIEs Non-VIEs Total VIEs Non-VIEs Total Three Months Ended Nine Months Ended Equity in earnings of unconsolidated affiliates $ 0.8 $ 0.5 $ 1.3 $ 2.4 $ 1.8 $ 4.2 Depreciation and amortization 0.1 — 0.1 0.2 — 0.2 Other income (expenses)—net 1.0 — 1.0 2.4 (5.6 ) (3.2 ) Net income $ 1.7 $ 0.5 $ 2.2 $ 4.6 $ (3.8 ) $ 0.8 Three Months Ended Nine Months Ended Equity in earnings of unconsolidated affiliates $ 0.5 $ 0.3 $ 0.8 $ 1.3 $ 0.6 $ 1.9 Depreciation and amortization — — — 0.1 — 0.1 Other income—net 0.6 — 0.6 1.9 — 1.9 Net income $ 1.1 $ 0.3 $ 1.4 $ 3.1 $ 0.6 $ 3.7

Related Party Transactions

Related Party Transactions	9 Months Ended
	Jun. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 12. RELATED PARTY TRANSACTIONS WGL and its subsidiaries engage in transactions in the ordinary course of business. Inter-company transactions and balances have been eliminated from the consolidated financial statements of WGL, except as described below. Washington Gas provides accounting, treasury, legal and other administrative and general support to affiliates, and files consolidated tax returns that include affiliated taxable transactions. Washington Gas bills its affiliates in accordance with regulatory requirements for the actual cost of providing these services, which approximates their market value. To the extent such billings are not paid, they are reflected in “Receivables from associated companies” on Washington Gas’ balance sheets. Washington Gas assigns or allocates these costs directly to its affiliates and, therefore, does not recognize revenues or expenses associated with providing these services. In connection with billing for unregulated third party marketers and with other miscellaneous billing processes, Washington Gas collects cash on behalf of affiliates and transfers the cash in a reasonable time period. Cash collected by Washington Gas on behalf of its affiliates but not transferred is recorded in “Payables to associated companies” on Washington Gas’ balance sheets. The following table presents the receivables and payables from associated companies as of June 30, 2015 and September 30, 2014 . Washington Gas Light Company Receivables / Payables from Associated Companies (In millions) June 30, 2015 September 30, 2014 Receivables from Associated Companies $ 4.8 $ 4.8 Payables to Associated Companies $ 66.9 $ 54.7 Washington Gas provides gas balancing services related to storage, injections, withdrawals and deliveries to all energy marketers participating in the sale of natural gas on an unregulated basis through the customer choice programs that operate in its service territory. These balancing services include the sale of natural gas supply commodities related to various peaking arrangements contractually supplied to Washington Gas and then partially allocated and assigned by Washington Gas to the energy marketers, including WGL Energy Services. Washington Gas records revenues for these balancing services pursuant to tariffs approved by the appropriate regulatory bodies. These related party amounts related to balancing services provided to WGL Energy Services have been eliminated in the consolidated financial statements of WGL. The following table shows the amounts Washington Gas charged WGL Energy Services for balance services. Washington Gas Light Company-Gas Balancing Service Charges Three Months Ended June 30, Nine Months Ended June 30, (In millions) 2015 2014 2015 2014 Gas balancing service charge $ 5.3 $ 2.8 $ 19.8 $ 21.0 As a result of these balancing services, an imbalance is created for volumes of natural gas received by Washington Gas that are not equal to the volumes of natural gas delivered to customers of the energy marketers. WGL Energy Services recognized accounts payable to Washington Gas in the amount of $7.0 million and an accounts receivable from Washington Gas in the amount of $0.02 million at June 30, 2015 and September 30, 2014 , respectively, related to an imbalance in gas volumes. Due to regulatory treatment, these payables and receivables are not eliminated in the consolidated financial statements of WGL. Refer to Note 1— Accounting Policies of the Notes to Consolidated Financial Statements of the combined Annual Report on Form 10-K for the fiscal year ended September 30, 2014 for further discussion of these imbalance transactions. Washington Gas participates in a Purchase of Receivables (POR) program as approved by the PSC of MD, whereby it purchases receivables from participating energy marketers at approved discount rates. In addition, WGL Energy Services participates in POR programs with certain Maryland and Pennsylvania utilities, whereby it sells its receivables to various utilities, including Washington Gas, at approved discount rates. The receivables purchased by Washington Gas are included in “Accounts receivable” in the accompanying balance sheet. Any activity between Washington Gas and WGL Energy Services related to the POR program has been eliminated in the accompanying financial statements for WGL. At June 30, 2015 and September 30, 2014 , Washington Gas had balances of $21.2 million and $7.7 million , respectively, of purchased receivables from WGL Energy Services.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 13. COMMITMENTS AND CONTINGENCIES REGULATED UTILITY OPERATIONS The following table summarizes the minimum contractual payments that Washington Gas will make under its pipeline transportation, storage and peaking contracts, as well as minimum contractual payments to purchase natural gas for the next five fiscal years and thereafter. Washington Gas Contract Minimums (In millions) Pipeline Contracts (a) Gas Purchase Commitments (b) Remainder of 2015 $ 55.4 $ 42.4 2016 218.7 359.6 2017 210.5 465.4 2018 211.3 460.9 2019 202.7 453.2 Thereafter 1,172.5 5,577.2 Total $ 2,071.1 $ 7,358.7 (a) Represents minimum payments for natural gas transportation, storage and peaking contracts that have expiration dates through fiscal year 2031. (b) Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on market prices at June 30, 2015 . REGULATORY CONTINGENCIES Certain legal and administrative proceedings incidental to our business, including regulatory contingencies, involve WGL and/or its subsidiaries. In our opinion, we have recorded an adequate provision for probable losses or refunds to customers for regulatory contingencies related to these proceedings. Virginia Gas Reserves. In the 2014 Session, the General Assembly of the Commonwealth of Virginia amended Title 56 of the Virginia Code. The legislative provisions are intended to encourage regulated utilities to invest in natural gas reserves, upstream pipelines and facilities that are reasonably expected to benefit customers by lowering costs, reducing volatility or lowering the utility’s supply risk. A regulated utility company can obtain the recovery through its rates charged to customers for the entire incurred cost, including the return of and a return on the investment in reserves, as well as all operating costs. Pursuant to the legislation, on May 6, 2015, WGL entered into a 20 -year agreement with Energy Corporation of America (ECA) to acquire natural gas reserves through non-operating working interests in 25 producing wells located in Pennsylvania's Appalachian Basin for $126 million . The purchase of the reserves is conditional upon approval by the Commonwealth of Virginia's State Corporation Commission (SCC of VA). Washington Gas filed an application with the SCC of VA on May 12, 2015, for approval of the gas reserves purchase agreement with ECA. Under a procedural schedule established by the SCC of VA to consider the application, a public hearing is scheduled on September 30, 2015. Under the law, the SCC of VA must issue a final decision on the application within 180 days, or by November 8, 2015. NON-UTILITY OPERATIONS On November 30, 2014, WGL through its subsidiary, WGL Midstream, entered into a gas sale and purchase, and capacity agreement with GAIL Global (USA) LNG LLC, a subsidiary of GAIL (India) Limited, under which WGL Midstream has agreed to sell and deliver a minimum of 340,000 dekatherms per day and up to 430,000 dekatherms per day of natural gas, for a term of 20 years from the in-service date of the export facility. The contract price is based on index pricing, but certain gas sales will occur at a market price per dekatherm of gas based on the estimate of prices prevailing at designated delivery points. WGL Midstream will make deliveries using transportation capacity released by GAIL through an asset management arrangement. On March 10, 2015, WGL Midstream entered into gas purchase commitments to buy 500,000 dekatherms of natural gas per day at index based prices for a 20 -year term. We will also be a shipper on the Mountain Valley Pipeline. These commitments were executed in conjunction with the investment in Mountain Valley. As a result of these agreements, purchase commitments for WGL Midstream have increased as reflected in the table below. The following table summarizes the minimum commitments and contractual obligations of WGL Energy Services and WGL Midstream for the next five fiscal years and thereafter. Contract Minimums WGL Energy Services WGL Midstream (In millions) Gas Purchase Commitments (a) Pipeline Contracts (b) Electric Purchase Commitments (c) Gas Purchase Commitments (d) Pipeline Contracts (b) Total Remainder of 2015 $ 37.1 $ 1.5 $ 153.3 $ 20.9 $ 5.9 $ 218.7 2016 146.3 2.2 418.1 258.9 20.4 845.9 2017 57.3 2.0 171.3 389.5 18.2 638.3 2018 6.7 1.5 36.5 1,217.4 15.4 1,277.5 2019 — 0.8 2.0 1,747.8 60.7 1,811.3 Thereafter — 1.7 0.5 35,647.5 1,093.2 36,742.9 Total $ 247.4 $ 9.7 $ 781.7 $ 39,282.0 $ 1,213.8 $ 41,534.6 (a) Represents fixed price commitments with city gate equivalent deliveries. (b) Represents minimum payments for natural gas transportation and storage contracts that have expiration dates through fiscal year 2044. (c) Represents electric purchase commitments that are based on existing fixed price and fixed volume contracts. Includes $18.2 million of commitments related to renewable energy credits. (d) Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on forward market prices as of June 30, 2015 . FINANCIAL GUARANTEES WGL has guaranteed payments primarily for certain purchases of natural gas and electricity on behalf of WGL Energy Services and for certain purchase commitments on behalf of WGL Midstream. At June 30, 2015 , these guarantees totaled $224.8 million and $311.8 million for WGL Energy Services and WGL Midstream, respectively. At June 30, 2015 , WGL also had guarantees on behalf of other subsidiaries totaling $9.1 million . The amount of such guarantees is periodically adjusted to reflect changes in the level of financial exposure related to these commitments. For all of our financial guarantees, WGL may cancel any or all future obligations upon written notice to the counterparty, but WGL would continue to be responsible for the obligations created under the guarantees prior to the effective date of the cancellation. WGL has also guaranteed payments for certain of our external partners. At June 30, 2015 , these guarantees totaled $8.1 million and the fair value of these guarantees was insignificant.

Pension and Other Post-Retireme

Pension and Other Post-Retirement Benefit Plans	9 Months Ended
	Jun. 30, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Pension and Other Post-Retirement Benefit Plans	NOTE 14. PENSION AND OTHER POST-RETIREMENT BENEFIT PLANS The following table shows the components of net periodic benefit costs (income) recognized in our financial statements during the three and nine months ended June 30, 2015 and 2014 . Components of Net Periodic Benefit Costs (Income) Three Months Ended June 30, 2015 2014 (In millions) Pension Benefits Health and Life Benefits Pension Benefits Health and Life Benefits Service cost $ 3.9 $ 1.8 $ 3.5 $ 1.6 Interest cost 9.7 3.7 10.1 3.8 Expected return on plan assets (11.2 ) (5.2 ) (10.2 ) (4.9 ) Amortization of prior service cost (credit) 0.1 (3.8 ) 0.1 (3.8 ) Amortization of actuarial loss 4.7 1.1 4.2 1.6 Net periodic benefit cost (income) 7.2 (2.4 ) 7.7 (1.7 ) Amount allocated to construction projects (1.2 ) 0.5 (1.1 ) 0.1 Amortization of regulatory asset/liability—net 1.8 (0.1 ) 1.7 0.2 Amount charged (credited) to expense $ 7.8 $ (2.0 ) $ 8.3 $ (1.4 ) Nine Months Ended June 30, 2015 2014 Service cost $ 11.6 $ 5.3 $ 10.5 $ 5.9 Interest cost 29.3 11.0 30.3 14.8 Expected return on plan assets (33.5 ) (15.6 ) (30.7 ) (14.4 ) Amortization of prior service cost (credit) 0.2 (11.4 ) 0.2 (5.8 ) Amortization of actuarial loss 14.1 3.3 12.6 3.5 Net periodic benefit cost (income) 21.7 (7.4 ) 22.9 4.0 Amount allocated to construction projects (3.4 ) 1.5 (3.1 ) (0.7 ) Amortization of regulatory asset/liability—net 5.3 (0.2 ) 5.3 0.4 Amount charged (credited) to expense $ 23.6 $ (6.1 ) $ 25.1 $ 3.7 Amounts included in the line item “Amortization of regulatory asset/liability—net,” as shown in the table above, represent the amortization of previously unrecovered costs of the applicable pension benefits or the health and life benefits as approved in the District of Columbia. These balances are being amortized over a five year period.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	NOTE 15. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following tables show the changes in accumulated other comprehensive income (loss) for WGL and Washington Gas by component for the three and nine months ended June 30, 2015 and 2014 . WGL Holdings, Inc. Changes in Accumulated Other Comprehensive Loss by Component (In thousands) Three Months Ended June 30, Nine Months Ended June 30, 2015 2014 2015 2014 Beginning Balance $ (11,643 ) $ (10,969 ) $ (7,961 ) $ (11,048 ) Qualified cash flow hedging instruments (a) 49 — (7,994 ) — Change in prior service cost (credit) (b) (170 ) 6,204 (511 ) 6,135 Amortization of actuarial loss (b) 529 404 1,503 604 Current-period other comprehensive income (loss) 408 6,608 (7,002 ) 6,739 Income tax expense (benefit) related to other comprehensive income (loss) 163 2,622 (3,565 ) 2,674 Ending Balance $ (11,398 ) $ (6,983 ) $ (11,398 ) $ (6,983 ) (a) Cash flow hedging instruments represent interest rate swaps agreements on debt issuances. Refer to Note 8- Derivative and weather-related instruments for further discussion of the interest rate swap agreements. (b) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14- Pension and other post-retirement benefit plans for additional details. Washington Gas Light Company Changes in Accumulated Other Comprehensive Loss by Component (In thousands) Three Months Ended June 30, Nine Months Ended June 30, 2015 2014 2015 2014 Beginning Balance $ (6,031 ) $ (10,969 ) $ (6,413 ) $ (11,048 ) Change in prior service cost (credit) (a) (170 ) 6,204 (511 ) 6,135 Amortization of actuarial loss (a) 529 404 1,503 604 Current-period other comprehensive income 359 6,608 992 6,739 Income tax expense related to other comprehensive income 143 2,622 394 2,674 Ending Balance $ (5,815 ) $ (6,983 ) $ (5,815 ) $ (6,983 ) (a) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14-Pension and other post-retirement benefit plans for additional details.

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation WGL Holdings, Inc. (WGL) is a holding company that owns all of the shares of common stock of Washington Gas Light Company (Washington Gas), a regulated natural gas utility, all of the shares of common stock of Washington Gas Resources Corporation (Washington Gas Resources) and Hampshire Gas Company (Hampshire). Washington Gas Resources owns all of the shares of common stock of four non-utility subsidiaries that include WGL Energy Services, Inc. (WGL Energy Services), WGL Energy Systems, Inc. (WGL Energy Systems), WGL Midstream, Inc. (WGL Midstream) and WGSW, Inc. (WGSW). Except where the content clearly indicates otherwise, “WGL,” “we,” “us” or “our” refers to the holding company or the consolidated entity of WGL Holdings, Inc. and all of its subsidiaries. Unless otherwise noted, these notes apply equally to WGL and Washington Gas. The condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Therefore, certain financial information and note disclosures accompanying annual financial statements prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) are omitted in this interim report. The interim consolidated financial statements and accompanying notes should be read in conjunction with the combined Annual Report on Form 10-K for WGL and Washington Gas for the fiscal year ended September 30, 2014. Due to the seasonal nature of our businesses, the results of operations for the periods presented in this report are not necessarily indicative of actual results for the full fiscal years ending September 30, 2015 and 2014 of either WGL or Washington Gas. The accompanying unaudited financial statements for WGL and Washington Gas reflect all normal recurring adjustments that are necessary, in our opinion, to present fairly the results of operations in accordance with GAAP. For a complete description of our accounting policies, refer to Note 1 of the Notes to Consolidated Financial Statements of the combined Annual Report on Form 10-K for WGL and Washington Gas for the fiscal year ended September 30, 2014.
Assets Held for Sale	Assets Held for Sale At June 30, 2015 , the Springfield Operations Center met the criteria to be reported as held for sale. Among other things, those criteria specify that (a) the asset must be available for immediate sale in its present condition subject only to terms that are usual and customary for sales of such assets and (b) the sale of the asset must be probable, and its transfer expected to qualify for recognition as a completed sale, within one year, with certain exceptions. The assets and liabilities associated with the Springfield Operations Center were reported as "Assets held for sale" and "Liabilities held for sale" on WGL's and Washington Gas' balance sheets as of June 30, 2015 .
Storage Gas Valuation Methods	Storage Gas Valuations For Washington Gas and WGL Energy Services, storage gas inventories are stated at the lower-of-cost or market as determined using the first-in, first-out method. For WGL Midstream, storage gas inventory is stated at the lower-of-cost or market using the weighted average cost method. Interim period inventory losses attributable to lower-of-cost or market adjustments may be reversed if the market value of the inventory is recovered by the end of the same fiscal year.
Accounting Standards Adopted Current Period	ACCOUNTING STANDARDS ADOPTED IN FISCAL YEAR 2015 ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (Topic 740) The standard requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset for net operating loss carryforwards, a similar loss, or a tax credit carryforward. October 1, 2014 As a result of the implementation of this standard, we reduced our deferred tax assets by a portion of our unrecognized tax benefits. The adoption of this standard did not have a material effect on our financial statements.
New Accounting Pronouncements	OTHER NEWLY ISSUED ACCOUNTING STANDARDS ASU 2015-03, Simplifying the Presentation of Debt Issuance Cost (Topic 835) The standard requires an entity to present debt issuance costs in the balance sheet as a direct deduction of the debt liability in a manner consistent with its accounting treatment of debt discounts. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis The standard changes the analysis to be performed in determining whether certain types of legal entities should be consolidated, specifically the analysis of limited partnerships and similar entities, fee arrangements and related party relationships. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) The standard establishes a comprehensive revenue recognition model clarifying the method used to determine the timing and requirements for revenue recognition from contracts with customers. The disclosure requirements under the new standard will enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. October 1, 2018 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements.
Income Tax Policy	Under ASC Topic 740, Income Taxes, Washington Gas recognizes any accrued interest associated with uncertain tax positions in interest expense and recognizes any accrued penalties associated with uncertain tax positions in other expenses in the statements of income.
Derivatives, Reporting Of Derivative Activity	Managing Price Risk. To manage price risk associated with acquiring natural gas supply for utility customers, Washington Gas enters into forward contracts, option contracts, financial contracts and other contracts, as authorized by its regulators. These instruments are accounted for as derivative instruments. Any gains and losses associated with these derivatives are recorded as regulatory liabilities or assets, respectively, to reflect the rate treatment for these economic hedging activities. Managing Interest-Rate Risk . Washington Gas utilizes derivative instruments that are designed to minimize the risk of interest-rate volatility associated with planned issuances of debt securities. Any gains and losses associated with these types of derivatives are recorded as regulatory liabilities or assets, respectively, and amortized in accordance with regulatory requirements, typically over the life of the newly issued debt. Non-Utility Operations Asset Optimization. WGL Midstream enters into derivative contracts for the purpose of optimizing its storage and transportation capacity as well as managing the transportation and storage assets on behalf of third parties. WGL Midstream does not designate these derivatives as hedges under ASC Topic 815; therefore, changes in the fair value of these derivative instruments are reflected in the earnings of our non-utility operations and may cause significant period-to-period volatility in earnings. The storage and transportation capacities utilized by WGL Midstream are not considered to be derivative instruments, and thus they are not recorded at fair value on our consolidated balance sheets. Managing Price Risk. WGL Energy Services enters into certain derivative contracts as part of managing the price risk associated with the sale and purchase of natural gas and electricity. WGL Energy Services designates a portion of these physical contracts related to the purchase of natural gas and electricity to serve our customers as "normal purchases and normal sales" and therefore, they are not subject to the fair value accounting requirements of ASC Topic 815. Derivative instruments not designated as "normal purchases and normal sales" are recorded at fair value on our consolidated balance sheets, and changes in the fair value of these derivative instruments are reflected in the earnings of our non-utility operations, which may cause significant period-to-period volatility in earnings. WGL Energy Services does not designate derivatives as hedges under ASC Topic 815. Managing Interest-Rate Risk . WGL utilizes derivative instruments that are designed to minimize the risk of interest-rate volatility associated with future debt issuances. WGL elected cash flow hedge accounting for its interest rate derivative instruments, which settled with the issuance of the related debt issuance in the first quarter of 2015. The effective portion of the gains and losses on the hedge were recorded within other comprehensive income and are being amortized over the life of the debt (through 2044). Regulated Utility Operations Washington Gas enters into contracts that qualify as derivative instruments and are accounted for under ASC Topic 815. These derivative instruments are recorded at fair value on our balance sheet and Washington Gas does not designate any derivatives as hedges under ASC Topic 815. Asset Optimization. Washington Gas optimizes the value of its long-term natural gas transportation and storage capacity resources during periods when these resources are not being used to physically serve utility customers. Specifically, Washington Gas utilizes its transportation capacity assets to benefit from favorable natural gas prices between different geographic locations and utilizes its storage capacity assets to benefit from favorable natural gas prices between different time periods. As part of this asset optimization program, Washington Gas enters into physical and financial derivative transactions in the form of forward, futures and option contracts with the primary objective of locking in operating margins that Washington Gas will ultimately realize. The derivatives used under this program are subject to mark-to-market accounting treatment while the capacity and transportation resources are not. Regulatory sharing mechanisms allow the profit from these transactions to be shared between Washington Gas’ shareholders and customers; therefore, any changes in fair value are recorded through earnings, or as regulatory assets or liabilities to the extent that gains and losses associated with these derivative instruments will be included in the rates charged to customers when they are realized. Valuation changes for the portion of net profits to be retained for shareholders may cause significant period-to-period volatility in earnings from unrealized gains and losses. This volatility does not change the locked-in operating margins that Washington Gas expects to ultimately realize from these transactions through the use of its storage and transportation capacity resources. All physically and financially settled contracts under our asset optimization program are reported on a net basis in the statements of income in “Utility cost of gas.” Collateral WGL utilizes standardized master netting agreements, which facilitate the netting of cash flows into a single net exposure for a given counterparty. As part of these master netting agreements, cash, letters of credit and parental guarantees may be required to be posted or obtained from counterparties in order to mitigate credit risk related to both derivatives and non-derivative positions. Under WGL’s offsetting policy, collateral balances are offset against the related counterparties’ derivative positions to the extent the application would not result in the over-collateralization of those derivative positions on the balance sheet. Any collateral posted that is not offset against open and settled derivative contracts is included in “Other prepayments” in the accompanying balance sheet. Collateral received and not offset against open and settled derivative contracts is included in “Customer deposits and advance payments” in the accompanying balance sheet.
Fair Value Measurement Policy	Our money market funds are Level 1 valuations and their carrying amount approximates fair value. Other short-term investments are primarily overnight investment accounts; therefore, their carrying amount approximates fair value based on Level 2 inputs. The maturity of our commercial paper outstanding at both June 30, 2015 and September 30, 2014 is under 30 days. Due to the short term nature of these notes, the carrying cost of our commercial paper approximates fair value using Level 2 inputs. Neither WGL’s nor Washington Gas’ long-term debt is actively traded. The fair value of long-term debt was estimated based on the quoted market prices of the U.S. Treasury issues having a similar term to maturity, adjusted for the credit quality of the debt issuer, WGL or Washington Gas. Our long-term debt fair value measurement is classified as Level 3. Non Recurring Basis During the nine months ended June 30, 2015 , Washington Gas Resources recorded an impairment charge of its investment in ASDHI to its fair value using the income approach. The amount of the impairment was equivalent to the amount of the carrying value of $5.6 million and was due to management’s assumption of the current valuation and expected return from the investment. The fair value of this investment was a Level 3 measurement. We measure the fair value of our financial assets and liabilities using a combination of the income and market approach in accordance with ASC Topic 820. These financial assets and liabilities primarily consist of derivatives recorded on our balance sheet under ASC Topic 815 and short-term investments, commercial paper and long-term debt outstanding required to be disclosed at fair value. Under ASC Topic 820, fair value is defined as the exit price, representing the amount that would be received in the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. To value our financial instruments, we use market data or assumptions that market participants would use, including assumptions about credit risk (both our own credit risk and the counterparty’s credit risk) and the risks inherent in the inputs to valuation. We enter into derivative contracts in the futures and over-the-counter (OTC) wholesale and retail markets. These markets are the principal markets for the respective wholesale and retail contracts. Our relevant market participants are our existing counterparties and others who have participated in energy transactions at our delivery points. These participants have access to the same market data as WGL. We value our derivative contracts based on an “in-exchange” premise, and valuations are generally based on pricing service data or indicative broker quotes depending on the market location. We measure the net credit exposure at the counterparty level where the right to set-off exists. The net exposure is determined using the mark-to-market exposure adjusted for collateral, letters of credit and parent guarantees. We use published default rates from Standard & Poor’s Ratings Services and Moody’s Investors Service as inputs for determining credit adjustments.
Segment Reporting Policy	We have four reportable operating segments: regulated utility, retail energy-marketing, commercial energy systems and midstream energy services. The division of these segments into separate revenue generating components is based upon regulation, products and services. Our chief operating decision maker is our Chief Executive Officer. During the first quarter of 2015, our chief operating decision maker began evaluating segment performance based on Earnings Before Interest and Taxes (EBIT). EBIT is defined as earnings before interest and taxes from continuing operations. Items we do not include in EBIT are interest expense, intercompany financing activity, dividends on Washington Gas preferred stock, and income taxes. EBIT includes transactions between reportable segments. We also evaluate our operating segments based on other relevant factors, such as penetration into their respective markets and return on equity.
Investment Policy	When determining how to account for our interests in other legal entities, WGL first evaluates if we are required to apply the variable interest entity (VIE) model to the entity, otherwise the entity is evaluated under the voting interest model. Under the VIE model, we have a controlling financial interest in a VIE (i.e. are the primary beneficiary) when we have current or potential rights that give us the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance combined with a variable interest that gives us the right to receive potentially significant benefits or the obligation to absorb potentially significant losses. When changes occur to the design of an entity, we reconsider whether it is subject to the VIE model. We continuously evaluate whether we have a controlling financial interest in a VIE. Under the voting interest model, we generally have a controlling financial interest in an entity where we currently hold, directly or indirectly, more than 50% of the voting rights or where we exercise control through substantive participating rights. However, we consider substantive rights held by other partners in determining if we hold a controlling financial interest, and in some cases, despite owning more than 50% of the common stock of an investee, an evaluation of our rights results in the determination that we do not have a controlling financial interest. We reevaluate whether we have a controlling financial interest in these entities when our voting or substantive participating rights change. Unconsolidated affiliates are unconsolidated VIEs and other entities evaluated under the voting interest method in which we do not have a controlling financial interest, but over which we have varying degrees of influence. Where we have significant influence, the affiliates are accounted for as equity method investments. Where we do not have significant influence, the affiliates are accounted for under the cost method. Investments in, and advances to, affiliated companies are presented on a one-line basis in the caption “Investments in unconsolidated affiliates” on our Consolidated Balance Sheet. WGL uses the Hypothetical Liquidation at Book Value (HLBV) methodology for certain equity method investments when the capital structure of the equity investment results in different liquidation rights and priorities than what is reflected by the underlying percentage ownership interests as defined by an equity investment agreement. For investments accounted for under the HLBV method, simply applying the percentage ownership interest to GAAP net income in order to determine earnings or losses does not accurately represent the income allocation and cash flow distributions that will ultimately be received by the investors. The equity investment agreements for ASD Solar, LP (ASD), Meade Pipeline Co LLC (Meade) and Mountain Valley Pipeline, LLC (Mountain Valley) have liquidation rights and priorities that are sufficiently different from the ownership percentages that the HLBV method was deemed appropriate. The calculation may vary in its complexity depending on the capital structure and the tax considerations for the investments. WGL applies HLBV using a balance sheet approach. A calculation is prepared at each balance sheet date to determine the amount that WGL would receive if an equity investment entity were to liquidate all of its assets (as valued in accordance with GAAP) and distribute that cash to the investors based on the contractually defined liquidation priorities. The difference between the calculated liquidation distribution amounts at the beginning and the end of the reporting period is WGL’s share of the earnings or losses from the equity investment for the period. Our investment in ASD is accounted for under the HLBV equity method of accounting; any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGSW’s investment balance. Our agreements with SunEdison and Nextility are accounted for as direct financing leases. WGSW records associated interest in the financing leases in “Other income (expenses)-net” line in the accompanying Consolidated Statement of Income. Meade is accounted for under the HLBV equity method of accounting, and any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGL’s investment balance. Constitution is accounted for under the equity method of accounting; any profits and losses are included in “Equity in earnings of unconsolidated affiliates” in the accompanying Consolidated Statement of Income and are added to or subtracted from the carrying amount of WGL’s investment balance. The equity method is considered appropriate because Constitution is an LLC with specific ownership accounts and ownership between five and fifty percent resulting in WGL Midstream maintaining a more than minor influence over the partnership operating and financing policies.

Accounting Policies (Tables)

Accounting Policies (Tables)	9 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Lower of Cost or Market Adjustments	The following table shows the lower-of-cost or market (LCM) adjustments recorded to net income for the three and nine months ended June 30, 2015 and 2014. Lower-of-Cost or Market Adjustments Pre-Tax Increase (Decrease) to Net Income Three Months Ended June 30, Nine Months Ended June 30, (In millions) 2015 2014 2015 2014 WGL (a) Operating revenues - non-utility $ 0.9 $ (0.8 ) $ (19.6 ) $ (0.8 ) Washington Gas Utility cost of gas $ — $ — $ (1.0 ) $ (0.4 ) Total Consolidated $ 0.9 $ (0.8 ) $ (20.6 ) $ (1.2 ) (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas.
Schedule of Accounting Policies	ACCOUNTING STANDARDS ADOPTED IN FISCAL YEAR 2015 Standard Description Date of adoption Effect on the financial statements or other significant matters ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (Topic 740) The standard requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar loss, or a tax credit carryforward. October 1, 2014 As a result of the implementation of this standard, we reduced our deferred tax assets by a portion of our unrecognized tax benefits. The adoption of this standard did not have a material effect on our financial statements. OTHER NEWLY ISSUED ACCOUNTING STANDARDS Standard Description Date of adoption Effect on the financial statements or other significant matters ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost The standard requires an entity to present debt issuance costs in the balance sheet as a direct deduction of the debt liability in a manner consistent with its accounting treatment of debt discounts. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis The standard changes the analysis to be performed in determining whether certain types of legal entities should be consolidated, specifically the analysis of limited partnerships and similar entities, fee arrangements and related party relationships. October 1, 2016 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) The standard establishes a comprehensive revenue recognition model clarifying the method used to determine the timing and requirements for revenue recognition from contracts with customers. The disclosure requirements under the new standard will enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. October 1, 2018 We are in the process of evaluating the impact the adoption of this standard will have on our financial statements.

Accounts Payable and Other Ac23

Accounts Payable and Other Accrued Liabilities (Tables)	9 Months Ended
	Jun. 30, 2015
Accounts Payable and Other Accrued Liabilities [Line Items]
Accounts Payable and Other Accrued Liabilities	The tables below provide details for the amounts included in “Accounts payable and other accrued liabilities” on the balance sheets for both WGL and Washington Gas. WGL Holdings, Inc. (In millions) June 30, 2015 September 30, 2014 Accounts payable—trade $ 234.6 $ 278.8 Employee benefits and payroll accruals 25.8 19.8 Other accrued liabilities 15.2 14.6 Total $ 275.6 $ 313.2
Washington Gas Light Company
Accounts Payable and Other Accrued Liabilities [Line Items]
Accounts Payable and Other Accrued Liabilities	Washington Gas Light Company (In millions) June 30, 2015 September 30, 2014 Accounts payable—trade $ 96.4 $ 146.4 Employee benefits and payroll accruals 24.1 18.2 Other accrued liabilities 8.5 11.9 Total $ 129.0 $ 176.5

Short-Term Debt (Tables)

Short-Term Debt (Tables)	9 Months Ended
	Jun. 30, 2015
Short-term Debt [Abstract]
Committed Credit Available	The following is a summary of committed credit available at June 30, 2015 and September 30, 2014 . Committed Credit Available (In millions) June 30, 2015 WGL (b) Washington Gas Total Consolidated Committed credit agreements Unsecured revolving credit facility, expires December 19, 2019 (a) $ 450.0 $ 350.0 $ 800.0 Less: Commercial Paper (156.0 ) — (156.0 ) Net committed credit available $ 294.0 $ 350.0 $ 644.0 Weighted average interest rate 0.27 % — % 0.27 % September 30, 2014 Committed credit agreements Unsecured revolving credit facility, expires April 3, 2017 (a) $ 450.0 $ 350.0 $ 800.0 Less: Commercial Paper (364.5 ) (89.0 ) (453.5 ) Net committed credit available $ 85.5 $ 261.0 $ 346.5 Weighted average interest rate 0.20 % 0.13 % 0.19 % (a) Both WGL and Washington Gas have the right to request extensions with the banks’ approval. WGL’s revolving credit facility permits it to borrow an additional $100 million , with the banks’ approval, for a total of $550 million . Washington Gas’ revolving credit facility permits it to borrow an additional $100 million , with the banks’ approval, for a total of $450 million . (b) WGL includes WGL Holdings and all subsidiaries other than Washington Gas.

Long-Term Debt (Table)

Long-Term Debt (Table)	9 Months Ended
	Jun. 30, 2015
Long-term Debt, by Current and Noncurrent [Abstract]
Senior Notes, MTN And Private Placement Notes Outstanding	The following tables show the outstanding notes as of June 30, 2015 and September 30, 2014 . Senior Notes, MTNs and Private Placement Notes Outstanding ($ In millions) WGL (a) Washington Gas Total Consolidated June 30, 2015 Long-term notes (b) $ 250.0 $ 741.0 $ 991.0 Weighted average interest rate 3.66 % 5.56 % 5.08 % September 30, 2014 Long-term notes (b) $ — $ 691.0 $ 691.0 Weighted average interest rate n/a 5.65 % 5.65 % (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. (b) Includes Senior Notes for WGL and both MTNs and private placement notes for Washington Gas. Represents face value including current maturities.
Senior Notes, MTN and Private Placement Issuances and Retirements	The following tables show senior notes, MTN and private placement issuances and retirements for the nine months ended June 30, 2015 and 2014 . Senior Notes, MTNs and Private Placement Issuances and Retirements ($ In millions) Principal (b) Interest Rate Effective Cost (c) Nominal Maturity Date Nine Months Ended June 30, 2015 WGL (a) Issuances: 10/24/2014 $ 100.0 2.25 % 2.42 % 11/1/2019 10/24/2014 125.0 4.60 % 5.11 % 11/1/2044 12/16/2014 25.0 4.60 % 5.53 % 11/1/2044 Total $ 250.0 Washington Gas Issuances: 12/15/2014 $ 50.0 4.24 % 4.41 % 12/15/2044 Total $ 50.0 Total consolidated issuances $ 300.0 Nine Months Ended June 30, 2014 Washington Gas Issuances: 12/5/2013 $ 75.0 5.00 % 4.95 % 12/15/2043 Total $ 75.0 Retirements: 11/7/2013 $ 37.0 4.88 % n/a 11/7/2013 Total $ 37.0 (a) WGL includes WGL Holdings and all subsidiaries other than Washington Gas. (b) Represents face amount. (c) The estimated effective cost of the issued notes, including consideration of issuance fees and hedge costs.

Common Shareholders' Equity (Ta

Common Shareholders' Equity (Tables)	9 Months Ended
	Jun. 30, 2015
Schedule of Capitalization, Equity [Line Items]
Components of Common Shareholders' Equity	The tables below reflect the components of “Common shareholders’ equity” for WGL and “Common shareholder’s equity” for Washington Gas for the nine months ended June 30, 2015 . WGL Holdings, Inc. Components of Common Shareholders’ Equity (In thousands) Common Stock Amount Paid-In Capital Retained Earnings Accumulated Other Comprehensive Loss, Net of Taxes Total Balance at September 30, 2014 $ 525,932 $ 11,847 $ 716,758 $ (7,961 ) $ 1,246,576 Net income — — 130,643 — 130,643 Other comprehensive loss — — — (3,437 ) (3,437 ) Repurchase of common stock (41,485 ) — — — (41,485 ) Stock-based compensation 1,009 1,934 — — 2,943 Dividends declared: Common stock — — (67,877 ) — (67,877 ) Preferred stock — — (990 ) — (990 ) Balance at June 30, 2015 $ 485,456 $ 13,781 $ 778,534 $ (11,398 ) $ 1,266,373
Washington Gas Light Company
Schedule of Capitalization, Equity [Line Items]
Components of Common Shareholders' Equity	Washington Gas Light Company Components of Common Shareholder’s Equity (In thousands) Common Stock Amount Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income (Loss), Net of Taxes Total Balance at September 30, 2014 $ 46,479 $ 480,620 $ 529,480 $ (6,413 ) $ 1,050,166 Net income — — 128,221 — 128,221 Other comprehensive income — — — 598 598 Stock-based compensation — 1,773 — — 1,773 Dividends declared: Common stock — — (59,051 ) — (59,051 ) Preferred stock — — (990 ) — (990 ) Balance at June 30, 2015 $ 46,479 $ 482,393 $ 597,660 $ (5,815 ) $ 1,120,717

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings per Share	The following table reflects the computation of our basic and diluted EPS for the three and nine months ended June 30, 2015 and 2014 . Basic and Diluted EPS (in thousands, except per share data) Net Income (Loss) Applicable to Common Stock Shares Per Share Amount Three Months Ended June 30, 2015 Basic EPS $ (15,690 ) 49,729 $ (0.32 ) Stock-based compensation plans — — Diluted EPS $ (15,690 ) 49,729 $ (0.32 ) Three Months Ended June 30, 2014 Basic EPS $ (11,940 ) 51,921 $ (0.23 ) Stock-based compensation plans — — Diluted EPS $ (11,940 ) 51,921 $ (0.23 ) Nine Months Ended June 30, 2015 Basic EPS $ 129,653 49,814 $ 2.60 Stock-based compensation plans — 242 Diluted EPS $ 129,653 50,056 $ 2.59 Nine Months Ended June 30, 2014 Basic EPS $ 67,902 51,871 $ 1.31 Stock-based compensation plans — 14 Diluted EPS $ 67,902 51,885 $ 1.31

Derivative and Weather Relate28

Derivative and Weather Related Instruments (Tables)	9 Months Ended
	Jun. 30, 2015
Derivative [Line Items]
Absolute Notional Amounts of Open Positions on Derivative Instruments	At June 30, 2015 and September 30, 2014 , respectively, the absolute notional amounts of our derivatives were as follows: Absolute Notional Amounts of Open Positions on Derivative Instruments Derivative transactions WGL Holdings, Inc. Washington Gas June 30, 2015 Notional Amounts Natural Gas (In millions of therms) Asset Optimization 21,296.2 13,722.3 Retail sales 0.8 — Other risk-management activities 1,786.9 1,377.4 Electricity (In millions of kWhs) Retail sales 4,474.0 — Other risk-management activities 20,683.5 — September 30, 2014 Natural Gas (In millions of therms) Asset Optimization 20,593.3 13,740.9 Retail sales 44.7 — Other risk-management activities 1,641.3 1,398.2 Electricity (In millions of kWhs) Retail sales 3,831.4 — Other risk-management activities 16,734.1 — Warrants (In millions of shares) 4.6 — Interest Rate Swaps (In millions of dollars) 150.0 —
Balance Sheet Classification of Derivative Instruments	The following tables present the balance sheet classification for all derivative instruments as of June 30, 2015 and September 30, 2014 . WGL Holdings, Inc. Balance Sheet Classification of Derivative Instruments (In millions) Derivative Instruments Not Designated as Hedging Instruments Derivative Instruments Designated as Hedging Instruments As of June 30, 2015 Gross Derivative Assets Gross Derivative Liabilities Gross Derivative Assets Gross Derivative Liabilities Netting of Collateral Total (a) Current Assets—Derivatives $ 14.5 $ (0.1 ) $ — $ — $ 1.3 $ 15.7 Deferred Charges and Other Assets—Derivatives 28.5 (0.2 ) — — — 28.3 Current Liabilities—Derivatives 23.9 (86.2 ) — — 3.5 (58.8 ) Deferred Credits—Derivatives 2.0 (362.0 ) — — 5.7 (354.3 ) Total $ 68.9 $ (448.5 ) $ — $ — $ 10.5 $ (369.1 ) As of September 30, 2014 Current Assets—Derivatives $ 20.8 $ (2.5 ) $ — $ — $ — $ 18.3 Deferred Charges and Other Assets—Derivatives 18.7 — — — — 18.7 Current Liabilities—Derivatives 15.4 (70.3 ) — (1.7 ) 8.0 (48.6 ) Deferred Credits—Derivatives 17.7 (316.4 ) — — 4.0 (294.7 ) Total $ 72.6 $ (389.2 ) $ — $ (1.7 ) $ 12.0 $ (306.3 )
Gains and (Losses) on Derivative Instruments	The following table presents all gains and losses associated with derivative instruments for the three and nine months ended June 30, 2015 and 2014 . Gains and Losses on Derivative Instruments (In millions) WGL Holdings, Inc. Washington Gas Three Months Ended June 30, 2015 2014 2015 2014 Recorded to income Operating revenues—non-utility $ (28.3 ) $ (21.3 ) $ — $ — Utility cost of gas (10.4 ) (2.0 ) (10.4 ) (2.0 ) Non-utility cost of energy-related sales 3.2 2.8 — — Other income-net — (0.6 ) — — Recorded to regulatory assets Gas costs (12.1 ) (12.5 ) (12.1 ) (12.5 ) Total $ (47.6 ) $ (33.6 ) $ (22.5 ) $ (14.5 ) Nine Months Ended June 30, 2015 2014 2015 2014 Recorded to income Operating revenues—non-utility $ 46.0 $ (105.6 ) $ — $ — Utility cost of gas (20.4 ) (125.7 ) (20.4 ) (125.7 ) Non-utility cost of energy-related sales (35.9 ) 46.7 — — Other income-net — (0.5 ) — — Interest expense (a) (0.5 ) — — — Recorded to regulatory assets Gas costs (36.0 ) (224.5 ) (36.0 ) (224.5 ) Other — 1.2 — 1.2 Recorded to other comprehensive income (b) (8.0 ) — — — Total $ (54.8 ) $ (408.4 ) $ (56.4 ) $ (349.0 ) (a) Represents $(0.4) million of ineffectiveness for our cash flow hedge and $(0.1) million of amortization of amounts previously recorded to Accumulated Other Comprehensive Income. (b) Represents the effective portion of our cash flow hedge of $(8.1) million less $(0.1) million of amortization that was reclassified to interest expense.
Potential Collateral Requirements for Derivative Liabilities with Credit-risk-Contingent Features	The following table shows the aggregate fair value of all derivative instruments with credit-related contingent features that are in a liability position, as well as the maximum amount of collateral that would be required if the most intrusive credit-risk-related contingent features underlying these agreements were triggered on June 30, 2015 and September 30, 2014 , respectively. Potential Collateral Requirements for Derivative Liabilities with Credit-Risk-Contingent Features (In millions) WGL Holdings, Inc. Washington Gas June 30, 2015 Derivative liabilities with credit-risk-contingent features $ 54.4 $ 20.1 Maximum potential collateral requirements 46.6 20.0 September 30, 2014 Derivative liabilities with credit-risk-contingent features $ 28.8 $ 20.6 Maximum potential collateral requirements 16.5 16.1
Washington Gas Light Company
Derivative [Line Items]
Balance Sheet Classification of Derivative Instruments	Washington Gas Light Company Balance Sheet Classification of Derivative Instruments (b) (In millions) As of June 30, 2015 Gross Gross Netting of Total (a) Current Assets—Derivatives $ 5.9 $ — $ 1.3 $ 7.2 Deferred Charges and Other Assets—Derivatives 12.4 (0.1 ) — 12.3 Current Liabilities—Derivatives 7.8 (44.8 ) — (37.0 ) Deferred Credits—Derivatives 0.6 (293.5 ) — (292.9 ) Total $ 26.7 $ (338.4 ) $ 1.3 $ (310.4 ) As of September 30, 2014 Current Assets—Derivatives $ 3.9 $ — $ — $ 3.9 Deferred Charges and Other Assets—Derivatives 9.5 — — 9.5 Current Liabilities—Derivatives 8.6 (43.2 ) 0.7 (33.9 ) Deferred Credits—Derivatives 4.2 (265.2 ) 0.2 (260.8 ) Total $ 26.2 $ (308.4 ) $ 0.9 $ (281.3 ) (a) WGL has elected to offset the fair value of recognized derivative instruments against the right to reclaim or the obligation to return collateral for derivative instruments executed under the same master netting arrangement in accordance with ASC 815. All recognized derivative contracts and associated financial collateral subject to a master netting arrangement or similar that is eligible for offset under ASC 815 have been presented net in the balance sheet. (b) Washington Gas did not have any derivative instruments outstanding that were designated as hedging instruments at June 30, 2015 or September 30, 2014 .

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Jun. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements Under the Fair Value Hierarchy	The following tables set forth financial instruments recorded at fair value as of June 30, 2015 and September 30, 2014 , respectively. A financial instrument’s classification within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy. WGL Holdings, Inc. Fair Value Measurements Under the Fair Value Hierarchy (In millions) Level 1 Level 2 Level 3 Total At June 30, 2015 Assets Natural gas related derivatives $ — $ 22.4 $ 22.4 $ 44.8 Electricity related derivatives — 2.1 22.0 24.1 Total Assets $ — $ 24.5 $ 44.4 $ 68.9 Liabilities Natural gas related derivatives $ — $ (41.0 ) $ (373.4 ) $ (414.4 ) Electricity related derivatives — (3.3 ) (30.8 ) (34.1 ) Total Liabilities $ — $ (44.3 ) $ (404.2 ) $ (448.5 ) At September 30, 2014 Assets Natural gas related derivatives $ — $ 22.7 $ 33.7 $ 56.4 Electricity related derivatives — 0.3 15.9 16.2 Total Assets $ — $ 23.0 $ 49.6 $ 72.6 Liabilities Natural gas related derivatives $ — $ (39.8 ) $ (328.4 ) $ (368.2 ) Electricity related derivatives — (0.1 ) (20.9 ) (21.0 ) Interest rate derivatives — (1.7 ) — (1.7 ) Total Liabilities $ — $ (41.6 ) $ (349.3 ) $ (390.9 )
Quantitative Information about Level 3 Fair Value Measurements	The following table includes quantitative information about the significant unobservable inputs used in the fair value measurement of our Level 3 financial instruments and the respective fair values of the net derivative asset and liability positions, by contract type, as of June 30, 2015 and September 30, 2014 . Quantitative Information about Level 3 Fair Value Measurements (In millions) Net Fair Value Valuation Techniques Unobservable Inputs Range WGL Holdings, Inc. Natural gas related derivatives $(351.0) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($1.629) - $4.920 Option Model Natural Gas Basis Price (per dekatherm) ($0.153) - ($0.090) Annualized Volatility of Spot Market Natural Gas 30.5% to 40.2% Electricity related derivatives $(8.8) Discounted Cash Flow Electricity Congestion Price (per megawatt hour) ($3.965) - $83.900 Washington Gas Light Company Natural gas related derivatives $(307.2) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($1.629) - $4.920 Net Fair Value WGL Holdings, Inc. Natural gas related derivatives $(294.7) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($2.101) - $6.154 Option Model Natural Gas Basis Price (per dekatherm) ($1.675) - $6.154 Annualized Volatility of Spot Market Natural Gas 30.9% - 589.6% Electricity related derivatives $(5.0) Discounted Cash Flow Electricity Congestion Price (per megawatt hour) ($2.85) - $90.95 Washington Gas Light Company Natural gas related derivatives $(270.6) Discounted Cash Flow Natural Gas Basis Price (per dekatherm) ($2.101) - $6.154
Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs	The following tables are a summary of the changes in the fair value of our derivative instruments that are measured at net fair value on a recurring basis in accordance with ASC Topic 820 using significant Level 3 inputs during the three and nine months ended June 30, 2015 and 2014 , respectively. WGL Holdings, Inc. Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Balance at April 1, 2015 $ (319.6 ) $ (10.5 ) $ — $ (330.1 ) Realized and unrealized gains (losses) Recorded to income (33.6 ) (4.8 ) — (38.4 ) Recorded to regulatory assets—gas costs (7.7 ) — — (7.7 ) Transfers out of Level 3 3.9 — — 3.9 Purchases — 3.9 — 3.9 Settlements 6.0 2.6 — 8.6 Balance at June 30, 2015 $ (351.0 ) $ (8.8 ) $ — $ (359.8 ) Three Months Ended June 30, 2014 Balance at April 1, 2014 $ (432.3 ) $ (2.2 ) $ 1.2 $ (433.3 ) Realized and unrealized gains (losses) Recorded to income (19.0 ) (2.3 ) (0.6 ) (21.9 ) Recorded to regulatory assets—gas costs (15.9 ) — — (15.9 ) Transfers out of Level 3 1.7 — — 1.7 Purchases — 2.3 — 2.3 Settlements 4.9 0.5 — 5.4 Balance at June 30, 2014 $ (460.6 ) $ (1.7 ) $ 0.6 $ (461.7 ) Nine Months Ended June 30, 2015 Balance at October 1, 2014 $ (294.7 ) $ (5.0 ) $ — $ (299.7 ) Realized and unrealized gains (losses) Recorded to income (51.0 ) (15.3 ) — (66.3 ) Recorded to regulatory assets—gas costs (48.0 ) — — (48.0 ) Transfers into Level 3 5.4 — — 5.4 Transfers out of Level 3 3.6 — — 3.6 Purchases — 7.3 — 7.3 Settlements 33.7 4.2 — 37.9 Balance at June 30, 2015 $ (351.0 ) $ (8.8 ) $ — $ (359.8 ) Nine Months Ended June 30, 2014 Balance at October 1, 2013 $ (155.2 ) $ 2.4 $ 1.1 $ (151.7 ) Realized and unrealized gains (losses) Recorded to income (151.6 ) 1.0 (0.5 ) (151.1 ) Recorded to regulatory assets—gas costs (198.7 ) — — (198.7 ) Transfers out of Level 3 1.7 — — 1.7 Purchases — 3.7 — 3.7 Settlements 43.2 (8.8 ) — 34.4 Balance at June 30, 2014 $ (460.6 ) $ (1.7 ) $ 0.6 $ (461.7 )
Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements	The table below sets forth the line items on the statements of income to which amounts are recorded for the three and nine months ended June 30, 2015 and 2014, respectively, related to fair value measurements using significant Level 3 inputs. WGL Holdings, Inc. Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Operating revenues—non-utility $ (22.3 ) $ (3.0 ) $ — $ (25.3 ) Utility cost of gas (7.6 ) — — (7.6 ) Non-utility cost of energy-related sales (3.7 ) (1.8 ) — (5.5 ) Total $ (33.6 ) $ (4.8 ) $ — $ (38.4 ) Three Months Ended June 30, 2014 Operating revenues—non-utility $ (14.3 ) $ (5.6 ) $ — $ (19.9 ) Utility cost of gas (4.5 ) — — (4.5 ) Other income-net — — (0.6 ) (0.6 ) Non-utility cost of energy-related sales (0.2 ) 3.3 — 3.1 Total $ (19.0 ) $ (2.3 ) $ (0.6 ) $ (21.9 ) Nine Months Ended June 30, 2015 Operating revenues—non-utility $ (20.7 ) $ 21.0 $ — $ 0.3 Utility cost of gas (30.3 ) — — (30.3 ) Non-utility cost of energy-related sales — (36.3 ) — (36.3 ) Total $ (51.0 ) $ (15.3 ) $ — $ (66.3 ) Nine Months Ended June 30, 2014 Operating revenues—non-utility $ (40.6 ) $ (30.1 ) $ — $ (70.7 ) Utility cost of gas (109.7 ) — — (109.7 ) Other income-net — — (0.5 ) (0.5 ) Non-utility cost of energy-related sales (1.3 ) 31.1 — 29.8 Total $ (151.6 ) $ 1.0 $ (0.5 ) $ (151.1 )
Unrealized Gains (Losses) Recorded for Level 3 Measurements	Unrealized gains (losses) attributable to derivative assets and liabilities measured using significant Level 3 inputs were recorded as follows, for the three and nine months ended June 30, 2015 and 2014 , respectively. WGL Holdings, Inc. Unrealized Gains (Losses) Recorded for Level 3 Measurements (In millions) Natural Gas Related Derivatives Electricity Related Derivatives Warrants Total Three Months Ended June 30, 2015 Recorded to income Operating revenues—non-utility $ (21.3 ) $ 0.8 $ — $ (20.5 ) Utility cost of gas (1.8 ) — — (1.8 ) Non-utility cost of energy-related sales (5.6 ) 2.5 — (3.1 ) Recorded to regulatory assets—gas costs (9.2 ) — — (9.2 ) Total $ (37.9 ) $ 3.3 $ — $ (34.6 ) Three Months Ended June 30, 2014 Recorded to income Operating revenues—non-utility $ (13.9 ) $ (5.8 ) $ — $ (19.7 ) Utility cost of gas (6.0 ) — — (6.0 ) Non-utility cost of energy-related sales (0.1 ) 5.3 — 5.2 Other income-net — — (0.6 ) (0.6 ) Recorded to regulatory assets—gas costs (17.6 ) — — (17.6 ) Total $ (37.6 ) $ (0.5 ) $ (0.6 ) $ (38.7 ) Nine Months Ended June 30, 2015 Recorded to income Operating revenues—non-utility $ (17.6 ) $ 21.7 $ — $ 4.1 Utility cost of gas (23.1 ) — — (23.1 ) Non-utility cost of energy-related sales (1.7 ) (31.5 ) — (33.2 ) Recorded to regulatory assets—gas costs (38.1 ) — — (38.1 ) Total $ (80.5 ) $ (9.8 ) $ — $ (90.3 ) Nine Months Ended June 30, 2014 Recorded to income Operating revenues—non-utility $ (44.6 ) $ (39.3 ) $ — $ (83.9 ) Utility cost of gas (100.4 ) — — (100.4 ) Non-utility cost of energy-related sales 3.3 35.8 — 39.1 Other income-net — — (0.5 ) (0.5 ) Recorded to regulatory assets—gas costs (190.7 ) — — (190.7 ) Total $ (332.4 ) $ (3.5 ) $ (0.5 ) $ (336.4 )
Fair Value of Financial Instruments	The following table presents the carrying amounts and estimated fair values of our financial instruments at June 30, 2015 and September 30, 2014 . WGL Holdings, Inc. Fair Value of Financial Instruments June 30, 2015 September 30, 2014 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value Money market funds (a) $ 74.6 $ 74.6 $ 9.7 $ 9.7 Other short-term investments (a) $ 1.0 $ 1.0 $ — $ — Commercial paper (b) $ 156.0 $ 156.0 $ 453.5 $ 453.5 Long-term debt (c) $ 950.5 $ 1,033.5 $ 679.2 $ 809.3
Washington Gas Light Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements Under the Fair Value Hierarchy	Washington Gas Light Company Fair Value Measurements Under the Fair Value Hierarchy (In millions) Level 1 Level 2 Level 3 Total At June 30, 2015 Assets Natural gas related derivatives $ — $ 14.8 $ 11.9 $ 26.7 Total Assets $ — $ 14.8 $ 11.9 $ 26.7 Liabilities Natural gas related derivatives $ — $ (19.3 ) $ (319.1 ) $ (338.4 ) Total Liabilities $ — $ (19.3 ) $ (319.1 ) $ (338.4 ) At September 30, 2014 Assets Natural gas related derivatives $ — $ 13.5 $ 12.7 $ 26.2 Total Assets $ — $ 13.5 $ 12.7 $ 26.2 Liabilities Natural gas related derivatives $ — $ (25.1 ) $ (283.3 ) $ (308.4 ) Total Liabilities $ — $ (25.1 ) $ (283.3 ) $ (308.4 )
Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs	Washington Gas Light Company Reconciliation of Fair Value Measurements Using Significant Level 3 Inputs (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Balance at April 1, 2015 $ (299.8 ) Realized and unrealized gains (losses) Recorded to income (7.6 ) Recorded to regulatory assets—gas costs (7.7 ) Transfers out of Level 3 2.8 Settlements 5.1 Balance at June 30, 2015 $ (307.2 ) Three Months Ended June 30, 2014 Balance at April 1, 2014 $ (382.6 ) Realized and unrealized gains (losses) Recorded to income (4.5 ) Recorded to regulatory assets—gas costs (15.9 ) Transfers out of Level 3 1.7 Settlements 4.4 Balance at June 30, 2014 $ (396.9 ) Nine Months Ended June 30, 2015 Balance at October 1, 2014 $ (270.6 ) Realized and unrealized gains (losses) Recorded to income (30.3 ) Recorded to regulatory assets—gas costs (48.0 ) Transfers into Level 3 5.4 Transfers out of Level 3 2.5 Settlements 33.8 Balance at June 30, 2015 $ (307.2 ) Nine Months Ended June 30, 2014 Balance at October 1, 2013 $ (133.6 ) Realized and unrealized gains (losses) Recorded to income (109.7 ) Recorded to regulatory assets—gas costs (198.7 ) Transfers out of Level 3 1.7 Settlements 43.4 Balance at June 30, 2014 $ (396.9 )
Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements	Washington Gas Light Company Realized and Unrealized Gains (Losses) Recorded to Income for Level 3 Measurements (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Utility cost of gas $ (7.6 ) Total $ (7.6 ) Three Months Ended June 30, 2014 Utility cost of gas $ (4.5 ) Total $ (4.5 ) Nine Months Ended June 30, 2015 Utility cost of gas $ (30.3 ) Total $ (30.3 ) Nine Months Ended June 30, 2014 Utility cost of gas $ (109.7 ) Total $ (109.7 )
Unrealized Gains (Losses) Recorded for Level 3 Measurements	Washington Gas Light Company Unrealized Gains (Losses) Recorded for Level 3 Measurements (In millions) Natural Gas Related Derivatives Three Months Ended June 30, 2015 Recorded to income - utility cost of gas $ (1.8 ) Recorded to regulatory assets—gas costs (9.2 ) Total $ (11.0 ) Three Months Ended June 30, 2014 Recorded to income - utility cost of gas $ (6.0 ) Recorded to regulatory assets—gas costs (17.6 ) Total $ (23.6 ) Nine Months Ended June 30, 2015 Recorded to income - utility cost of gas $ (23.1 ) Recorded to regulatory assets—gas costs (38.1 ) Total $ (61.2 ) Nine Months Ended June 30, 2014 Recorded to income - utility cost of gas $ (100.4 ) Recorded to regulatory assets—gas costs (190.7 ) Total $ (291.1 )
Fair Value of Financial Instruments	Washington Gas Light Company Fair Value of Financial Instruments June 30, 2015 September 30, 2014 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value Money market funds (a) $ 70.4 $ 70.4 $ 4.3 $ 4.3 Other short-term investments (a) $ 1.0 $ 1.0 $ — $ — Commercial paper (b) $ — $ — $ 89.0 $ 89.0 Long-term debt (c) $ 702.2 $ 795.9 $ 679.2 $ 809.3 (a) Balance is located in cash and cash equivalents in the accompanying balance sheets. These amounts may be offset by outstanding checks. (b) Balance is located in notes payable in the accompanying balance sheets. (c) Less current maturities and unamortized discounts.

Operating Segment Reporting (Ta

Operating Segment Reporting (Tables)	9 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Operating Segment Financial Information	The following tables present operating segment information for the three and nine months ended June 30, 2015 and 2014 . Operating Segment Financial Information (In thousands) Operating Revenues (a) Depreciation and Amortization Equity in Earnings of Unconsolidated Affiliates EBIT Total Assets Capital Expenditures Equity Method Investments Three Months Ended June 30, 2015 Regulated utility $ 190,345 $ 27,740 $ — $ (6,262 ) $ 4,113,166 $ 75,413 $ — Retail energy-marketing 268,249 151 — 16,654 464,086 — — Commercial energy systems 14,674 2,787 544 3,750 613,124 27,271 64,323 Midstream energy services (25,801 ) 31 718 (26,607 ) 203,591 85 56,967 Other activities — — — (970 ) 106,861 — — Eliminations (b) (6,294 ) (13 ) — (541 ) (492,363 ) — — Total consolidated $ 441,173 $ 30,696 $ 1,262 $ (13,976 ) $ 5,008,465 $ 102,769 $ 121,290 Three Months Ended June 30, 2014 Regulated utility $ 197,752 $ 25,840 $ — $ 4,456 $ 3,809,747 $ 76,073 $ — Retail energy-marketing 275,339 204 — 1,286 387,990 5 — Commercial energy systems 14,260 1,611 733 5,012 459,509 18,171 68,309 Midstream energy services (15,869 ) 31 85 (16,806 ) 181,880 — 22,426 Other activities — — — (2,391 ) 224,220 — 413 Eliminations (b) (3,982 ) (64 ) — (532 ) (502,662 ) — — Total consolidated $ 467,500 $ 27,622 $ 818 $ (8,975 ) $ 4,560,684 $ 94,249 $ 91,148 Nine Months Ended June 30, 2015 Regulated utility $ 1,193,232 $ 81,958 $ — $ 238,645 $ 4,113,166 $ 235,707 $ — Retail energy-marketing 1,003,339 470 — 39,185 464,086 5 — Commercial energy systems 35,745 7,693 1,623 4,731 613,124 81,246 64,323 Midstream energy services (17,997 ) 93 1,865 (23,343 ) 203,591 85 56,967 Other activities — — 750 (8,915 ) 106,861 — — Eliminations (b) (22,176 ) (55 ) — (592 ) (492,363 ) — — Total consolidated $ 2,192,143 $ 90,159 $ 4,238 $ 249,711 $ 5,008,465 $ 317,043 $ 121,290 Nine Months Ended June 30, 2014 Regulated utility $ 1,304,975 $ 76,945 $ — $ 158,444 $ 3,809,747 $ 181,821 $ — Retail energy-marketing 1,035,711 558 — 5,186 387,990 93 — Commercial energy systems 27,013 4,255 1,496 5,961 459,509 59,536 68,309 Midstream energy services (21,938 ) 93 355 (29,410 ) 181,880 — 22,426 Other activities — — — (10,227 ) 224,220 — 413 Eliminations (b) (23,714 ) (335 ) — 110 (502,662 ) — — Total consolidated $ 2,322,047 $ 81,516 $ 1,851 $ 130,064 $ 4,560,684 $ 241,450 $ 91,148 (a) Operating revenues are reported gross of revenue taxes. Revenue taxes of both the regulated utility and the retail energy-marketing segments include gross receipt taxes. Revenue taxes of the regulated utility segment also include public service commission fees, franchise fees and energy taxes. Operating revenue amounts in the “Eliminations” row represent total intersegment revenues associated with sales from the regulated utility segment to the retail energy-marketing segment. Midstream Energy Services’ cost of energy related sales is netted with its gross revenues. (b) Intersegment eliminations include any mark-to market valuations associated with trading activities between WGL Midstream and WGL Energy Services, intercompany loans and a timing difference between Commercial Energy Systems’ recognition of revenue for the sale of Renewable Energy Credits (RECs) to Retail Energy-Marketing and Retail Energy-Marketing’s recognition of the associated expense. Retail Energy-Marketing has recorded a portion of the REC’s purchased as inventory to be used in future periods at which time they will be expensed.
Reconciliation from EBIT to net income applicable to common stock	The following table provides a reconciliation from EBIT to net income applicable to common stock. Three Months Ended June 30, Nine Months Ended June 30, (In thousands) 2015 2014 2015 2014 Total consolidated EBIT $ (13,976 ) $ (8,975 ) $ 249,711 $ 130,064 Interest expense 13,140 9,503 38,704 28,020 Income (loss) before income taxes (27,116 ) (18,478 ) 211,007 102,044 Income tax expense (benefit) (11,756 ) (6,868 ) 80,364 33,152 Net income (loss) (15,360 ) (11,610 ) 130,643 68,892 Dividends on Washington Gas Light Company preferred stock 330 330 990 990 Net income (loss) applicable to common stock $ (15,690 ) $ (11,940 ) $ 129,653 $ 67,902

Other Investment (Tables)

Other Investment (Tables)	9 Months Ended
	Jun. 30, 2015
Other Investments [Abstract]
Minimum Payments Receivable for Direct Financing Leases	Minimum future lease payments receivable under direct financing leases over the next five fiscal years and thereafter are as follows: Minimum Payments Receivable for Direct Financing Leases (In millions) Remainder of 2015 $ 2.4 2016 2.5 2017 2.4 2018 2.3 2019 2.2 Thereafter 22.6 Total $ 34.4
Location of Investments	The income statement location of the investments discussed in this footnote for the three and nine months ended June 30, 2015 and 2014 are as follows: WGL Holdings, Inc. Income Statement Location of Other Investments (In millions) VIEs Non-VIEs Total VIEs Non-VIEs Total Three Months Ended Nine Months Ended Equity in earnings of unconsolidated affiliates $ 0.8 $ 0.5 $ 1.3 $ 2.4 $ 1.8 $ 4.2 Depreciation and amortization 0.1 — 0.1 0.2 — 0.2 Other income (expenses)—net 1.0 — 1.0 2.4 (5.6 ) (3.2 ) Net income $ 1.7 $ 0.5 $ 2.2 $ 4.6 $ (3.8 ) $ 0.8 Three Months Ended Nine Months Ended Equity in earnings of unconsolidated affiliates $ 0.5 $ 0.3 $ 0.8 $ 1.3 $ 0.6 $ 1.9 Depreciation and amortization — — — 0.1 — 0.1 Other income—net 0.6 — 0.6 1.9 — 1.9 Net income $ 1.1 $ 0.3 $ 1.4 $ 3.1 $ 0.6 $ 3.7 The balance sheet location of the investments discussed in this footnote at June 30, 2015 and September 30, 2014 are as follows: WGL Holdings, Inc. Balance Sheet Location of Other Investments As of June 30, 2015 (in millions) VIEs Non-VIEs Total Assets Investments in unconsolidated affiliates $ 85.9 $ 35.4 $ 121.3 Investments in direct financing leases, capital leases 25.8 — 25.8 Accounts receivable 3.3 2.5 (a) 5.8 Total assets $ 115.0 $ 37.9 $ 152.9 As of September 30, 2014 (in millions) Assets Investments in unconsolidated affiliates $ 72.6 $ 27.9 $ 100.5 Investments in direct financing leases, capital leases 18.2 — 18.2 Accounts receivable 1.7 — 1.7 Total assets $ 92.5 $ 27.9 $ 120.4 (a) Represents the financing provided to another partner in Mountain Valley to fund its capital commitment. Acquired ownership interest represents the collateral for repayment of the financing.

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Jun. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	The following table shows the amounts Washington Gas charged WGL Energy Services for balance services. Washington Gas Light Company-Gas Balancing Service Charges Three Months Ended June 30, Nine Months Ended June 30, (In millions) 2015 2014 2015 2014 Gas balancing service charge $ 5.3 $ 2.8 $ 19.8 $ 21.0 The following table presents the receivables and payables from associated companies as of June 30, 2015 and September 30, 2014 . Washington Gas Light Company Receivables / Payables from Associated Companies (In millions) June 30, 2015 September 30, 2014 Receivables from Associated Companies $ 4.8 $ 4.8 Payables to Associated Companies $ 66.9 $ 54.7

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Minimum Commitments and Contractual Obligations	The following table summarizes the minimum commitments and contractual obligations of WGL Energy Services and WGL Midstream for the next five fiscal years and thereafter. Contract Minimums WGL Energy Services WGL Midstream (In millions) Gas Purchase Commitments (a) Pipeline Contracts (b) Electric Purchase Commitments (c) Gas Purchase Commitments (d) Pipeline Contracts (b) Total Remainder of 2015 $ 37.1 $ 1.5 $ 153.3 $ 20.9 $ 5.9 $ 218.7 2016 146.3 2.2 418.1 258.9 20.4 845.9 2017 57.3 2.0 171.3 389.5 18.2 638.3 2018 6.7 1.5 36.5 1,217.4 15.4 1,277.5 2019 — 0.8 2.0 1,747.8 60.7 1,811.3 Thereafter — 1.7 0.5 35,647.5 1,093.2 36,742.9 Total $ 247.4 $ 9.7 $ 781.7 $ 39,282.0 $ 1,213.8 $ 41,534.6 (a) Represents fixed price commitments with city gate equivalent deliveries. (b) Represents minimum payments for natural gas transportation and storage contracts that have expiration dates through fiscal year 2044. (c) Represents electric purchase commitments that are based on existing fixed price and fixed volume contracts. Includes $18.2 million of commitments related to renewable energy credits. (d) Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on forward market prices as of June 30, 2015 . The following table summarizes the minimum contractual payments that Washington Gas will make under its pipeline transportation, storage and peaking contracts, as well as minimum contractual payments to purchase natural gas for the next five fiscal years and thereafter. Washington Gas Contract Minimums (In millions) Pipeline Contracts (a) Gas Purchase Commitments (b) Remainder of 2015 $ 55.4 $ 42.4 2016 218.7 359.6 2017 210.5 465.4 2018 211.3 460.9 2019 202.7 453.2 Thereafter 1,172.5 5,577.2 Total $ 2,071.1 $ 7,358.7 (a) Represents minimum payments for natural gas transportation, storage and peaking contracts that have expiration dates through fiscal year 2031. (b) Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on market prices at June 30, 2015 .

Pension and Other Post-Retire34

Pension and Other Post-Retirement Benefit Plan (Tables)	9 Months Ended
	Jun. 30, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Components of Net Periodic Benefit Costs (Income)	The following table shows the components of net periodic benefit costs (income) recognized in our financial statements during the three and nine months ended June 30, 2015 and 2014 . Components of Net Periodic Benefit Costs (Income) Three Months Ended June 30, 2015 2014 (In millions) Pension Benefits Health and Life Benefits Pension Benefits Health and Life Benefits Service cost $ 3.9 $ 1.8 $ 3.5 $ 1.6 Interest cost 9.7 3.7 10.1 3.8 Expected return on plan assets (11.2 ) (5.2 ) (10.2 ) (4.9 ) Amortization of prior service cost (credit) 0.1 (3.8 ) 0.1 (3.8 ) Amortization of actuarial loss 4.7 1.1 4.2 1.6 Net periodic benefit cost (income) 7.2 (2.4 ) 7.7 (1.7 ) Amount allocated to construction projects (1.2 ) 0.5 (1.1 ) 0.1 Amortization of regulatory asset/liability—net 1.8 (0.1 ) 1.7 0.2 Amount charged (credited) to expense $ 7.8 $ (2.0 ) $ 8.3 $ (1.4 ) Nine Months Ended June 30, 2015 2014 Service cost $ 11.6 $ 5.3 $ 10.5 $ 5.9 Interest cost 29.3 11.0 30.3 14.8 Expected return on plan assets (33.5 ) (15.6 ) (30.7 ) (14.4 ) Amortization of prior service cost (credit) 0.2 (11.4 ) 0.2 (5.8 ) Amortization of actuarial loss 14.1 3.3 12.6 3.5 Net periodic benefit cost (income) 21.7 (7.4 ) 22.9 4.0 Amount allocated to construction projects (3.4 ) 1.5 (3.1 ) (0.7 ) Amortization of regulatory asset/liability—net 5.3 (0.2 ) 5.3 0.4 Amount charged (credited) to expense $ 23.6 $ (6.1 ) $ 25.1 $ 3.7

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss) by Component	The following tables show the changes in accumulated other comprehensive income (loss) for WGL and Washington Gas by component for the three and nine months ended June 30, 2015 and 2014 . WGL Holdings, Inc. Changes in Accumulated Other Comprehensive Loss by Component (In thousands) Three Months Ended June 30, Nine Months Ended June 30, 2015 2014 2015 2014 Beginning Balance $ (11,643 ) $ (10,969 ) $ (7,961 ) $ (11,048 ) Qualified cash flow hedging instruments (a) 49 — (7,994 ) — Change in prior service cost (credit) (b) (170 ) 6,204 (511 ) 6,135 Amortization of actuarial loss (b) 529 404 1,503 604 Current-period other comprehensive income (loss) 408 6,608 (7,002 ) 6,739 Income tax expense (benefit) related to other comprehensive income (loss) 163 2,622 (3,565 ) 2,674 Ending Balance $ (11,398 ) $ (6,983 ) $ (11,398 ) $ (6,983 ) (a) Cash flow hedging instruments represent interest rate swaps agreements on debt issuances. Refer to Note 8- Derivative and weather-related instruments for further discussion of the interest rate swap agreements. (b) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14- Pension and other post-retirement benefit plans for additional details. Washington Gas Light Company Changes in Accumulated Other Comprehensive Loss by Component (In thousands) Three Months Ended June 30, Nine Months Ended June 30, 2015 2014 2015 2014 Beginning Balance $ (6,031 ) $ (10,969 ) $ (6,413 ) $ (11,048 ) Change in prior service cost (credit) (a) (170 ) 6,204 (511 ) 6,135 Amortization of actuarial loss (a) 529 404 1,503 604 Current-period other comprehensive income 359 6,608 992 6,739 Income tax expense related to other comprehensive income 143 2,622 394 2,674 Ending Balance $ (5,815 ) $ (6,983 ) $ (5,815 ) $ (6,983 ) (a) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14-Pension and other post-retirement benefit plans for additional details.

Accounting Policies (Details)

Accounting Policies (Details) $ in Millions		3 Months Ended		9 Months Ended
		Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)subsidiary	Jun. 30, 2014USD ($)
Inventory [Line Items]
Lower of cost or market adjustment		$ 0.9	$ (0.8)	$ (20.6)	$ (1.2)
Washington Gas Resources
Inventory [Line Items]
Number of subsidiaries | subsidiary				4
WGL | Operating revenues - non-utility
Inventory [Line Items]
Lower of cost or market adjustment	[1]	0.9	(0.8)	$ (19.6)	(0.8)
Washington Gas Light Company
Inventory [Line Items]
Operation and maintenance expense				0.5
Washington Gas Light Company | Utility cost of gas
Inventory [Line Items]
Lower of cost or market adjustment		$ 0	$ 0	$ (1)	$ (0.4)
[1]	WGL includes WGL Holdings and all subsidiaries other than Washington Gas.

Accounts Payable and Other Ac37

Accounts Payable and Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2014
Accounts Payable and Other Accrued Liabilities [Line Items]
Accounts payable - trade	$ 234,600	$ 278,800
Employee benefits and payroll accruals	25,800	19,800
Other accrued liabilities	15,200	14,600
Accounts Payable and Accrued Liabilities, Current, Total	275,615	313,221
Washington Gas Light Company
Accounts Payable and Other Accrued Liabilities [Line Items]
Accounts payable - trade	96,400	146,400
Employee benefits and payroll accruals	24,100	18,200
Other accrued liabilities	8,500	11,900
Accounts Payable and Accrued Liabilities, Current, Total	$ 128,968	$ 176,467

Short-Term Debt (Details)

Short-Term Debt (Details)		Jun. 30, 2015USD ($)extension	Sep. 30, 2014USD ($)
Short-term Debt [Line Items]
Less: Commercial Paper		$ (156,000,000)	$ (453,500,000)
Committed Credit
Short-term Debt [Line Items]
Unsecured revolving credit facility	[1]	800,000,000	800,000,000
Less: Commercial Paper		(156,000,000)	(453,500,000)
Net committed credit available		$ 644,000,000	$ 346,500,000
Weighted average interest rate		0.27%	0.19%
WGL
Short-term Debt [Line Items]
Outstanding bank loans		$ 0	$ 0
WGL | Committed Credit
Short-term Debt [Line Items]
Unsecured revolving credit facility	[1],[2]	450,000,000	450,000,000
Less: Commercial Paper	[2]	(156,000,000)	(364,500,000)
Net committed credit available	[2]	$ 294,000,000	$ 85,500,000
Weighted average interest rate	[2]	0.27%	0.20%
Number of one-year extension options | extension		2
Revolving credit facility maximum borrowing capacity		$ 550,000,000
Revolving credit facility additional borrowings		100,000,000
Washington Gas Light Company
Short-term Debt [Line Items]
Less: Commercial Paper		0	$ (89,000,000)
Outstanding bank loans		0	0
Washington Gas Light Company | Committed Credit
Short-term Debt [Line Items]
Unsecured revolving credit facility	[1]	350,000,000	350,000,000
Less: Commercial Paper		0	(89,000,000)
Net committed credit available		$ 350,000,000	$ 261,000,000
Weighted average interest rate		0.00%	0.13%
Number of one-year extension options | extension		2
Revolving credit facility maximum borrowing capacity		$ 450,000,000
Revolving credit facility additional borrowings		$ 100,000,000
[1]	Both WGL and Washington Gas have the right to request extensions with the banks’ approval. WGL’s revolving credit facility permits it to borrow an additional $100 million, with the banks’ approval, for a total of $550 million. Washington Gas’ revolving credit facility permits it to borrow an additional $100 million, with the banks’ approval, for a total of $450 million.
[2]	WGL includes WGL Holdings and all subsidiaries other than Washington Gas.

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($)		9 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2014
Total Consolidated
Debt Instrument [Line Items]
Long-term notes	[1]	$ 991,000,000		$ 691,000,000
Interest rate		5.08%		5.65%
WGL | Issuances
Debt Instrument [Line Items]
Long-term notes	[2],[3]	$ 250,000,000
WGL | Total Consolidated
Debt Instrument [Line Items]
Long-term notes	[1],[4]	$ 250,000,000		$ 0
Interest rate	[4]	3.66%
WGL | 11/1/2019 | Issuances
Debt Instrument [Line Items]
Interest rate	[3]	2.25%
Issuance Date	[3]	Oct. 24, 2014
Principal	[2],[3]	$ 100,000,000
Effective cost	[3],[5]	2.42%
Nominal Maturity Date	[3]	Nov. 1, 2019
WGL | 11/1/2044 | Issuances
Debt Instrument [Line Items]
Interest rate	[3]	4.60%
Issuance Date	[3]	Oct. 24, 2014
Principal	[2],[3]	$ 125,000,000
Effective cost	[3],[5]	5.11%
Nominal Maturity Date	[3]	Nov. 1, 2044
WGL | 11/1/2044 | Issuances
Debt Instrument [Line Items]
Interest rate	[3]	4.60%
Issuance Date	[3]	Dec. 16, 2014
Principal	[2],[3]	$ 25,000,000
Effective cost	[3],[5]	5.53%
Nominal Maturity Date	[3]	Nov. 1, 2044
Washington Gas Light Company | Total consolidated issuances
Debt Instrument [Line Items]
Long-term notes	[2]	$ 300,000,000
Washington Gas Light Company | Issuances
Debt Instrument [Line Items]
Long-term notes	[2]	$ 50,000,000	$ 75,000,000
Interest rate		4.24%	5.00%
Issuance Date		Dec. 15, 2014	Dec. 5, 2013
Principal	[2]	$ 50,000,000	$ 75,000,000
Effective cost	[5]	4.41%	4.95%
Nominal Maturity Date		Dec. 15, 2044	Dec. 15, 2043
Washington Gas Light Company | Retirements
Debt Instrument [Line Items]
Long-term notes	[2]		$ 37,000,000
Interest rate			4.88%
Principal	[2]		$ 37,000,000
Nominal Maturity Date			Nov. 7, 2013
Retirement Date			Nov. 7, 2013
Washington Gas Light Company | Total Consolidated
Debt Instrument [Line Items]
Long-term notes	[1]	$ 741,000,000		$ 691,000,000
Interest rate		5.56%		5.65%
Washington Gas Light Company | Medium-Term Notes
Debt Instrument [Line Items]
Unused borrowing capacity amount				$ 275,000,000
[1]	Includes Senior Notes for WGL and both MTNs and private placement notes for Washington Gas. Represents face value including current maturities.
[2]	Represents face amount.
[3]	WGL includes WGL Holdings and all subsidiaries other than Washington Gas.
[4]	WGL includes WGL Holdings and all subsidiaries other than Washington Gas.
[5]	The estimated effective cost of the issued notes, including consideration of issuance fees and hedge costs.

Common Shareholders' Equity (De

Common Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2014
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			$ 1,246,576
Net income	$ (15,360)	$ (11,610)	130,643	$ 68,892
Other comprehensive income (loss)	245	3,986	(3,437)	4,065
Repurchase of common stock			(41,485)
Stock-based compensation			2,943
Dividends declared:
Common stock			(67,877)
Preferred stock			(990)
Common shareholders' equity, ending balance	$ 1,266,373		$ 1,266,373
Shares outstanding (in shares)	49,728,662		49,728,662		50,656,553
Common Stock
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			$ 525,932
Repurchase of common stock			(41,485)
Dividends declared:
Common shareholders' equity, ending balance	$ 485,456		485,456
Paid-In Capital
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			11,847
Stock-based compensation			1,934
Dividends declared:
Common shareholders' equity, ending balance	13,781		13,781
Retained Earnings
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			716,758
Net income			130,643
Dividends declared:
Common stock			(67,877)
Preferred stock			(990)
Common shareholders' equity, ending balance	778,534		778,534
Accumulated Other Comprehensive Loss, Net of Taxes
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			(7,961)
Other comprehensive income (loss)			(3,437)
Dividends declared:
Common shareholders' equity, ending balance	(11,398)		(11,398)
Washington Gas Light Company
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			1,050,166
Net income	(11,424)	(191)	128,221	88,122
Other comprehensive income (loss)	216	$ 3,986	598	$ 4,065
Stock-based compensation			1,773
Dividends declared:
Common stock			(59,051)
Preferred stock			(990)
Common shareholders' equity, ending balance	$ 1,120,717		$ 1,120,717
Shares outstanding (in shares)	46,479,536		46,479,536		46,479,536
Washington Gas Light Company | Common Stock
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			$ 46,479
Dividends declared:
Common shareholders' equity, ending balance	$ 46,479		46,479
Washington Gas Light Company | Paid-In Capital
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			480,620
Stock-based compensation			1,773
Dividends declared:
Common shareholders' equity, ending balance	482,393		482,393
Washington Gas Light Company | Retained Earnings
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			529,480
Net income			128,221
Dividends declared:
Common stock			(59,051)
Preferred stock			(990)
Common shareholders' equity, ending balance	597,660		597,660
Washington Gas Light Company | Accumulated Other Comprehensive Loss, Net of Taxes
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Common shareholders' equity, beginning balance			(6,413)
Other comprehensive income (loss)			598
Dividends declared:
Common shareholders' equity, ending balance	$ (5,815)		$ (5,815)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Net Income (Loss) applicable to common stock	$ (15,690)	$ (11,940)	$ 129,653	$ 67,902
Basic EPS (in shares)	49,729,000	51,921,000	49,814,000	51,871,000
Stock-based compensation plans (in shares)	0	0	242,000	14,000
Diluted EPS (in shares)	49,729,000	51,921,000	50,056,000	51,885,000
Basic EPS (in dollars per share)	$ (0.32)	$ (0.23)	$ 2.60	$ 1.31
Diluted EPS (in dollars per share)	$ (0.32)	$ (0.23)	$ 2.59	$ 1.31
Antidilutive securities excluded from computation of earnings per share			0	0
Performance Shares
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive securities excluded from computation of earnings per share	317,000
Weighted Average Stock Option
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive securities excluded from computation of earnings per share		5,000
Dividend Reinvestment
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive securities excluded from computation of earnings per share		2,000

Income Taxes-Balance Sheet (Det

Income Taxes-Balance Sheet (Details) - USD ($)	3 Months Ended
	Dec. 31, 2013	Jun. 30, 2015	Sep. 30, 2014
Income Tax Expense Benefit Details [Line Items]
Unrecognized tax benefits		$ 31,100,000	$ 32,600,000
Washington Gas Light Company
Income Tax Expense Benefit Details [Line Items]
Accrued interest related to uncertain tax positions		$ 0	$ 100,000
Regulatory asset, amortization period	five year

Derivative and Weather Relate43

Derivative and Weather Related Instruments Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015USD ($)Counterparties	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)Counterparties	Jun. 30, 2014USD ($)	Sep. 30, 2014USD ($)
Washington Gas Light Company
Asset Optimization [Abstract]
Gain (loss) on asset optimization transactions, net pretax	$ (2.9)	$ 1.9	$ 14.2	$ (78.3)
Unrealized gain (loss) on asset optimization derivative instruments, net pretax	(10.4)	(1.2)	(13.3)	(105.3)
Derivative, Collateral [Abstract]
Right to reclaim cash	6.5		6.5		$ 8.2
Obligation to return cash	$ 4.1		$ 4.1		2.5
Concentration of Credit Risk
Number of counterparties | Counterparties	2		2
Percentage of credit exposure	10.00%		10.00%
Obligation to counterparties	$ 23.4		$ 23.4
WGL Energy Services
Derivative, Collateral [Abstract]
Right to reclaim cash	8.9		8.9		5.7
Obligation to return cash	0.1		0.1
Collateral already posted, aggregate fair value	$ 5.7		$ 5.7		5.3
Concentration of Credit Risk
Number of counterparties | Counterparties	2		2
Percentage of credit exposure	10.00%		10.00%
Obligation to counterparties	$ 0.2		$ 0.2
Gain (losses) on weather related instruments, pretax	(0.5)	$ (0.9)	2.7	$ 4.5
WGL Midstream
Derivative, Collateral [Abstract]
Right to reclaim cash	9.9		9.9		$ 11.4
Obligation to return cash	$ 0.1		$ 0.1
Concentration of Credit Risk
Number of counterparties | Counterparties	2		2
Percentage of credit exposure	10.00%		10.00%
Obligation to counterparties	$ 15		$ 15

Derivative and Weather Relate44

Derivative and Weather Related Instruments (Details) MMBTU in Thousands, shares in Millions, kWh in Millions, $ in Millions		Jun. 30, 2015USD ($)kWhMMBTU	Sep. 30, 2014USD ($)kWhMMBTUshares
Absolute Notional Amounts of Open Positions on Derivative Instruments
Warrant notional amounts (in shares) | shares			4.6
Interest rate swap notional principal value			$ 150
Balance Sheet Classification of Derivative Instruments
Netting of Collateral		$ 10.5	12
Total	[1]	(369.1)	(306.3)
Derivative Instruments Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		0	0
Gross Derivative Liabilities		0	(1.7)
Derivative Instruments Not Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		68.9	72.6
Gross Derivative Liabilities		(448.5)	(389.2)
Current assets- derivatives
Balance Sheet Classification of Derivative Instruments
Netting of Collateral		1.3	0
Total	[1]	15.7	18.3
Current assets- derivatives | Derivative Instruments Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		0	0
Gross Derivative Liabilities		0	0
Current assets- derivatives | Derivative Instruments Not Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		14.5	20.8
Gross Derivative Liabilities		(0.1)	(2.5)
Deferred Charges and Other Assets-Derivatives
Balance Sheet Classification of Derivative Instruments
Netting of Collateral		0	0
Total	[1]	28.3	18.7
Deferred Charges and Other Assets-Derivatives | Derivative Instruments Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		0	0
Gross Derivative Liabilities		0	0
Deferred Charges and Other Assets-Derivatives | Derivative Instruments Not Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		28.5	18.7
Gross Derivative Liabilities		(0.2)	0
Current liabilities- Derivatives
Balance Sheet Classification of Derivative Instruments
Netting of Collateral		3.5	8
Total	[1]	(58.8)	(48.6)
Current liabilities- Derivatives | Derivative Instruments Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		0	0
Gross Derivative Liabilities		0	(1.7)
Current liabilities- Derivatives | Derivative Instruments Not Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		23.9	15.4
Gross Derivative Liabilities		(86.2)	(70.3)
Deferred Credits-Derivatives
Balance Sheet Classification of Derivative Instruments
Netting of Collateral		5.7	4
Total	[1]	(354.3)	(294.7)
Deferred Credits-Derivatives | Derivative Instruments Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		0	0
Gross Derivative Liabilities		0	0
Deferred Credits-Derivatives | Derivative Instruments Not Designated as Hedging Instruments
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets		2	17.7
Gross Derivative Liabilities		$ (362)	$ (316.4)
Asset Optimization
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		2,129,620	2,059,330
Retail sales
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		80	4,470
Electricity notional amounts (in kWhs) | kWh		4,474	3,831.4
Other risk-management activities
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		178,690	164,130
Electricity notional amounts (in kWhs) | kWh		20,683.5	16,734.1
Washington Gas Light Company
Absolute Notional Amounts of Open Positions on Derivative Instruments
Warrant notional amounts (in shares) | shares			0
Interest rate swap notional principal value			$ 0
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets	[2]	$ 26.7	26.2
Gross Derivative Liabilities	[2]	(338.4)	(308.4)
Netting of Collateral	[2]	1.3	0.9
Total	[1],[2]	(310.4)	(281.3)
Washington Gas Light Company | Current assets- derivatives
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets	[2]	5.9	3.9
Gross Derivative Liabilities	[2]	0	0
Netting of Collateral	[2]	1.3	0
Total	[1],[2]	7.2	3.9
Washington Gas Light Company | Deferred Charges and Other Assets-Derivatives
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets	[2]	12.4	9.5
Gross Derivative Liabilities	[2]	(0.1)	0
Netting of Collateral	[2]	0	0
Total	[1],[2]	12.3	9.5
Washington Gas Light Company | Current liabilities- Derivatives
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets	[2]	7.8	8.6
Gross Derivative Liabilities	[2]	(44.8)	(43.2)
Netting of Collateral	[2]	0	0.7
Total	[1],[2]	(37)	(33.9)
Washington Gas Light Company | Deferred Credits-Derivatives
Balance Sheet Classification of Derivative Instruments
Gross Derivative Assets	[2]	0.6	4.2
Gross Derivative Liabilities	[2]	(293.5)	(265.2)
Netting of Collateral	[2]	0	0.2
Total	[1],[2]	$ (292.9)	$ (260.8)
Washington Gas Light Company | Asset Optimization
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		1,372,230	1,374,090
Washington Gas Light Company | Retail sales
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		0	0
Electricity notional amounts (in kWhs) | kWh		0	0
Washington Gas Light Company | Other risk-management activities
Absolute Notional Amounts of Open Positions on Derivative Instruments
Natural gas notional amounts (in mmbtu) | MMBTU		137,740	139,820
Electricity notional amounts (in kWhs) | kWh		0	0
[1]	WGL has elected to offset the fair value of recognized derivative instruments against the right to reclaim or the obligation to return collateral for derivative instruments executed under the same master netting arrangement in accordance with ASC 815. All recognized derivative contracts and associated financial collateral subject to a master netting arrangement or similar that is eligible for offset under ASC 815 have been presented net in the balance sheet.
[2]	Washington Gas did not have any derivative instruments outstanding that were designated as hedging instruments at June 30, 2015 or September 30, 2014.

Derivative and Weather Relate45

Derivative and Weather Related Instruments (Gains and Losses) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Gains and (Losses) on Derivative Instruments
Recorded to other comprehensive income	[1]	$ 49	$ 0	$ (7,994)	$ 0
Gains (losses) on derivative instruments		(47,600)	(33,600)	(54,800)	(408,400)
Operating revenues—non-utility
Gains and (Losses) on Derivative Instruments
Recorded to income		(28,300)	(21,300)	46,000	(105,600)
Utility cost of gas
Gains and (Losses) on Derivative Instruments
Recorded to income		(10,400)	(2,000)	(20,400)	(125,700)
Non-utility cost of energy-related sales
Gains and (Losses) on Derivative Instruments
Recorded to income		3,200	2,800	(35,900)	46,700
Other income-net
Gains and (Losses) on Derivative Instruments
Recorded to income		0	(600)	0	(500)
Gas costs
Gains and (Losses) on Derivative Instruments
Recorded to regulatory assets/liabilities		(12,100)	(12,500)	(36,000)	(224,500)
Other
Gains and (Losses) on Derivative Instruments
Recorded to regulatory assets/liabilities				0	1,200
Interest expense
Gains and (Losses) on Derivative Instruments
Recorded to income	[2]			(500)	0
Ineffectiveness of cash flow hedge	[3]			(400)
Amortization of amounts recorded to AOCI				(100)
Recorded to other comprehensive income
Gains and (Losses) on Derivative Instruments
Recorded to other comprehensive income	[3]			(8,000)	0
Gains (losses) on derivative instruments				(8,100)
Amortization of amounts recorded to AOCI	[3]			100
Washington Gas Light Company
Gains and (Losses) on Derivative Instruments
Gains (losses) on derivative instruments		(22,500)	(14,500)	(56,400)	(349,000)
Washington Gas Light Company | Operating revenues—non-utility
Gains and (Losses) on Derivative Instruments
Recorded to income		0	0	0	0
Washington Gas Light Company | Utility cost of gas
Gains and (Losses) on Derivative Instruments
Recorded to income		(10,400)	(2,000)	(20,400)	(125,700)
Washington Gas Light Company | Non-utility cost of energy-related sales
Gains and (Losses) on Derivative Instruments
Recorded to income		0	0	0	0
Washington Gas Light Company | Other income-net
Gains and (Losses) on Derivative Instruments
Recorded to income		0	0	0	0
Washington Gas Light Company | Gas costs
Gains and (Losses) on Derivative Instruments
Recorded to regulatory assets/liabilities		$ (12,100)	$ (12,500)	(36,000)	(224,500)
Washington Gas Light Company | Other
Gains and (Losses) on Derivative Instruments
Recorded to regulatory assets/liabilities				0	1,200
Washington Gas Light Company | Interest expense
Gains and (Losses) on Derivative Instruments
Recorded to income	[2]			0	0
Washington Gas Light Company | Recorded to other comprehensive income
Gains and (Losses) on Derivative Instruments
Recorded to other comprehensive income	[3]			$ 0	$ 0
[1]	Cash flow hedging instruments represent interest rate swaps agreements on debt issuances. Refer to Note 8- Derivative and weather-related instruments for further discussion of the interest rate swap agreements.
[2]	Represents $(0.4) million of ineffectiveness for our cash flow hedge and $(0.1) million of amortization of amounts previously recorded to Accumulated Other Comprehensive Income.
[3]	Represents the effective portion of our cash flow hedge of $(8.1) million less $(0.1) million of amortization that was reclassified to interest expense.

Derivative and Weather Relate46

Derivative and Weather Related Instruments (Aggregate Fair Value) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Potential Collateral Requirements for Derivative Liabilities with Credit-risk-Contingent Features
Derivative liabilities with credit-risk-contingent features	$ 54.4	$ 28.8
Maximum potential collateral requirements	46.6	16.5
Washington Gas Light Company
Potential Collateral Requirements for Derivative Liabilities with Credit-risk-Contingent Features
Derivative liabilities with credit-risk-contingent features	20.1	20.6
Maximum potential collateral requirements	$ 20	$ 16.1

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Hierarchy) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	$ 68.9	$ 72.6
Liabilities	(448.5)	(390.9)
Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	44.8	56.4
Liabilities	(414.4)	(368.2)
Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	24.1	16.2
Liabilities	(34.1)	(21)
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Liabilities		(1.7)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	0	0
Liabilities	0	0
Level 1 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	0	0
Liabilities	0	0
Level 1 | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	0	0
Liabilities	0	0
Level 1 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Liabilities		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	24.5	23
Liabilities	(44.3)	(41.6)
Level 2 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	22.4	22.7
Liabilities	(41)	(39.8)
Level 2 | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	2.1	0.3
Liabilities	(3.3)	(0.1)
Level 2 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Liabilities		(1.7)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	44.4	49.6
Liabilities	(404.2)	(349.3)
Level 3 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	22.4	33.7
Liabilities	(373.4)	(328.4)
Level 3 | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	22	15.9
Liabilities	(30.8)	(20.9)
Level 3 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Liabilities		0
Washington Gas Light Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	26.7	26.2
Liabilities	(338.4)	(308.4)
Washington Gas Light Company | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	26.7	26.2
Liabilities	(338.4)	(308.4)
Washington Gas Light Company | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	0	0
Liabilities	0	0
Washington Gas Light Company | Level 1 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	0	0
Liabilities	0	0
Washington Gas Light Company | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	14.8	13.5
Liabilities	(19.3)	(25.1)
Washington Gas Light Company | Level 2 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	14.8	13.5
Liabilities	(19.3)	(25.1)
Washington Gas Light Company | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	11.9	12.7
Liabilities	(319.1)	(283.3)
Washington Gas Light Company | Level 3 | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Assets	11.9	12.7
Liabilities	$ (319.1)	$ (283.3)

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative information) (Details) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)$ / MwH$ / dekatherm	Sep. 30, 2014USD ($)$ / MwH$ / dekatherm	Mar. 31, 2015USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Sep. 30, 2013USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net Fair Value | $	$ (359.8)	$ (299.7)	$ (330.1)	$ (461.7)	$ (433.3)	$ (151.7)
Natural Gas Related Derivatives
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net Fair Value | $	$ (351)	$ (294.7)	(319.6)	(460.6)	(432.3)	(155.2)
Natural Gas Related Derivatives | Discounted Cash Flow | Maximum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	4.920	6.154
Natural Gas Related Derivatives | Discounted Cash Flow | Minimum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	(1.629)	(2.101)
Natural Gas Related Derivatives | Option Model | Maximum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	(0.090)	6.154
Natural Gas Related Derivatives | Option Model | Maximum | Annualized Volatility Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Option Volatility Percentage	40.20%	589.60%
Natural Gas Related Derivatives | Option Model | Minimum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	(0.153)	(1.675)
Natural Gas Related Derivatives | Option Model | Minimum | Annualized Volatility Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Option Volatility Percentage	30.50%	30.90%
Electricity Related Derivatives
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net Fair Value | $	$ (8.8)	$ (5)	(10.5)	(1.7)	(2.2)	2.4
Electricity Related Derivatives | Discounted Cash Flow | Maximum | Electricity Congestion Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour) | $ / MwH	83.900	90.95
Electricity Related Derivatives | Discounted Cash Flow | Minimum | Electricity Congestion Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour) | $ / MwH	(3.965)	(2.85)
Washington Gas Light Company | Discounted Cash Flow | Maximum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	4.920	6.154
Washington Gas Light Company | Discounted Cash Flow | Minimum | Natural Gas Basis Price
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Input price (usd per dekatherm/megawatt hour)	(1.629)	(2.101)
Washington Gas Light Company | Natural Gas Related Derivatives
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net Fair Value | $	$ (307.2)	$ (270.6)	$ (299.8)	$ (396.9)	$ (382.6)	$ (133.6)

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation with Level 3 Inputs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ (330.1)	$ (433.3)	$ (299.7)	$ (151.7)
Recorded to income	(38.4)	(21.9)	(66.3)	(151.1)
Recorded to regulatory assets—gas costs	(7.7)	(15.9)	(48)	(198.7)
Transfers into Level 3			5.4
Transfers out of Level 3	3.9	1.7	3.6	1.7
Purchases	3.9	2.3	7.3	3.7
Settlements	8.6	5.4	37.9	34.4
Ending balance	(359.8)	(461.7)	(359.8)	(461.7)
Natural Gas Related Derivatives
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	(319.6)	(432.3)	(294.7)	(155.2)
Recorded to income	(33.6)	(19)	(51)	(151.6)
Recorded to regulatory assets—gas costs	(7.7)	(15.9)	(48)	(198.7)
Transfers into Level 3			5.4
Transfers out of Level 3	3.9	1.7	3.6	1.7
Purchases	0	0	0	0
Settlements	6	4.9	33.7	43.2
Ending balance	(351)	(460.6)	(351)	(460.6)
Electricity Related Derivatives
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	(10.5)	(2.2)	(5)	2.4
Recorded to income	(4.8)	(2.3)	(15.3)	1
Recorded to regulatory assets—gas costs	0	0	0	0
Transfers into Level 3			0
Transfers out of Level 3	0	0	0	0
Purchases	3.9	2.3	7.3	3.7
Settlements	2.6	0.5	4.2	(8.8)
Ending balance	(8.8)	(1.7)	(8.8)	(1.7)
Warrant
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	0	1.2	0	1.1
Recorded to income	0	(0.6)	0	(0.5)
Recorded to regulatory assets—gas costs	0	0	0	0
Transfers into Level 3			0
Transfers out of Level 3	0	0	0	0
Purchases	0	0	0	0
Settlements	0	0	0	0
Ending balance	0	0.6	0	0.6
Washington Gas Light Company | Natural Gas Related Derivatives
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	(299.8)	(382.6)	(270.6)	(133.6)
Recorded to income	(7.6)	(4.5)	(30.3)	(109.7)
Recorded to regulatory assets—gas costs	(7.7)	(15.9)	(48)	(198.7)
Transfers into Level 3			5.4
Transfers out of Level 3	2.8	1.7	2.5	1.7
Settlements	5.1	4.4	33.8	43.4
Ending balance	$ (307.2)	$ (396.9)	$ (307.2)	$ (396.9)

Fair Value Measurements (Realiz

Fair Value Measurements (Realized and Unrealized Gains and Losses with Level 3 Measurements) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	$ (38.4)	$ (21.9)	$ (66.3)	$ (151.1)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to regulatory assets - gas costs	(9.2)	(17.6)	(38.1)	(190.7)
Total	(34.6)	(38.7)	(90.3)	(336.4)
Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(33.6)	(19)	(51)	(151.6)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to regulatory assets - gas costs	(9.2)	(17.6)	(38.1)	(190.7)
Total	(37.9)	(37.6)	(80.5)	(332.4)
Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(4.8)	(2.3)	(15.3)	1
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to regulatory assets - gas costs	0	0	0	0
Total	3.3	(0.5)	(9.8)	(3.5)
Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	0	(0.6)	0	(0.5)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to regulatory assets - gas costs	0	0	0	0
Total	0	(0.6)	0	(0.5)
Operating revenues—non-utility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(25.3)	(19.9)	0.3	(70.7)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(20.5)	(19.7)	4.1	(83.9)
Operating revenues—non-utility | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(22.3)	(14.3)	(20.7)	(40.6)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(21.3)	(13.9)	(17.6)	(44.6)
Operating revenues—non-utility | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(3)	(5.6)	21	(30.1)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	0.8	(5.8)	21.7	(39.3)
Operating revenues—non-utility | Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	0	0	0	0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	0	0	0	0
Utility cost of gas
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(7.6)	(4.5)	(30.3)	(109.7)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(1.8)	(6)	(23.1)	(100.4)
Utility cost of gas | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(7.6)	(4.5)	(30.3)	(109.7)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(1.8)	(6)	(23.1)	(100.4)
Utility cost of gas | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	0	0	0	0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	0	0	0	0
Utility cost of gas | Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	0	0	0	0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	0	0	0	0
Other income-net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements		(0.6)		(0.5)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income		(0.6)		(0.5)
Other income-net | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements		0		0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income		0		0
Other income-net | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements		0		0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income		0		0
Other income-net | Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements		(0.6)		(0.5)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income		(0.6)		(0.5)
Non-utility cost of energy-related sales
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(5.5)	3.1	(36.3)	29.8
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(3.1)	5.2	(33.2)	39.1
Non-utility cost of energy-related sales | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(3.7)	(0.2)	0	(1.3)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	(5.6)	(0.1)	(1.7)	3.3
Non-utility cost of energy-related sales | Electricity Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(1.8)	3.3	(36.3)	31.1
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	2.5	5.3	(31.5)	35.8
Non-utility cost of energy-related sales | Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	0	0	0	0
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	0	0	0	0
Washington Gas Light Company | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(7.6)	(4.5)	(30.3)	(109.7)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to regulatory assets - gas costs	(9.2)	(17.6)	(38.1)	(190.7)
Total	(11)	(23.6)	(61.2)	(291.1)
Washington Gas Light Company | Utility cost of gas | Natural Gas Related Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized and unrealized gains (losses) recorded to income for Level 3 measurements	(7.6)	(4.5)	(30.3)	(109.7)
Unrealized Gains (Losses) Recorded for Level 3 Measurements
Recorded to income	$ (1.8)	$ (6)	$ (23.1)	$ (100.4)

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Amounts and Estimated Fair Value) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Sep. 30, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper		$ 156,000	$ 453,500
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money Market Funds	[1]	74,600	9,700
Other Short-term Investments	[1]	1,000	0
Commercial Paper	[2]	156,000	453,500
Long-term debt	[3]	950,500	679,200
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money Market Funds	[1]	74,600	9,700
Other Short-term Investments	[1]	1,000	0
Commercial Paper	[2]	156,000	453,500
Long-term debt	[3]	1,033,500	809,300
Washington Gas Light Company
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper		0	89,000
Washington Gas Light Company | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money Market Funds	[1]	70,400	4,300
Other Short-term Investments	[1]	1,000	0
Commercial Paper	[2]	0	89,000
Long-term debt	[3]	702,200	679,200
Washington Gas Light Company | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money Market Funds	[1]	70,400	4,300
Other Short-term Investments	[1]	1,000	0
Commercial Paper	[2]	0	89,000
Long-term debt	[3]	$ 795,900	$ 809,300
[1]	Balance is located in cash and cash equivalents in the accompanying balance sheets. These amounts may be offset by outstanding checks.
[2]	Balance is located in notes payable in the accompanying balance sheets.
[3]	Less current maturities and unamortized discounts.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) $ in Millions	9 Months Ended
	Jun. 30, 2015USD ($)
Fair Value Disclosures [Abstract]
Impairment loss	$ 5.6

Operating Segment (Narrative) (

Operating Segment (Narrative) (Details)	9 Months Ended
	Jun. 30, 2015segment
Segment Reporting [Abstract]
Number of Operating Segments	4

Operating Segment (Details)

Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2014
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	$ 441,173	$ 467,500	$ 2,192,143	$ 2,322,047
Depreciation and Amortization		30,696	27,622	90,159	81,516
Equity in Earnings of Unconsolidated Affiliates		1,262	818	4,238	1,851
EBIT		(13,976)	(8,975)	249,711	130,064
Total Assets		5,008,465	4,560,684	5,008,465	4,560,684	$ 4,856,499
Capital Expenditures		102,769	94,249	317,043	241,450
Equity Method Investments		121,290	91,148	121,290	91,148
Other activities
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	0	0	0	0
Depreciation and Amortization		0	0	0	0
Equity in Earnings of Unconsolidated Affiliates		0	0	750	0
EBIT		(970)	(2,391)	(8,915)	(10,227)
Total Assets		106,861	224,220	106,861	224,220
Capital Expenditures		0	0	0	0
Equity Method Investments		0	413	0	413
Eliminations
Operating Segment Financial Information [Line Items]
Operating Revenues	[1],[2]	(6,294)	(3,982)	(22,176)	(23,714)
Depreciation and Amortization	[2]	(13)	(64)	(55)	(335)
Equity in Earnings of Unconsolidated Affiliates	[2]	0	0	0	0
EBIT	[2]	(541)	(532)	(592)	110
Total Assets	[2]	(492,363)	(502,662)	(492,363)	(502,662)
Capital Expenditures	[2]	0	0	0	0
Equity Method Investments	[2]	0	0	0	0
Regulated utility | Operating Segments
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	190,345	197,752	1,193,232	1,304,975
Depreciation and Amortization		27,740	25,840	81,958	76,945
Equity in Earnings of Unconsolidated Affiliates		0	0	0	0
EBIT		(6,262)	4,456	238,645	158,444
Total Assets		4,113,166	3,809,747	4,113,166	3,809,747
Capital Expenditures		75,413	76,073	235,707	181,821
Equity Method Investments		0	0	0	0
Retail energy-marketing | Operating Segments
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	268,249	275,339	1,003,339	1,035,711
Depreciation and Amortization		151	204	470	558
Equity in Earnings of Unconsolidated Affiliates		0	0	0	0
EBIT		16,654	1,286	39,185	5,186
Total Assets		464,086	387,990	464,086	387,990
Capital Expenditures		0	5	5	93
Equity Method Investments		0	0	0	0
Commercial energy systems | Operating Segments
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	14,674	14,260	35,745	27,013
Depreciation and Amortization		2,787	1,611	7,693	4,255
Equity in Earnings of Unconsolidated Affiliates		544	733	1,623	1,496
EBIT		3,750	5,012	4,731	5,961
Total Assets		613,124	459,509	613,124	459,509
Capital Expenditures		27,271	18,171	81,246	59,536
Equity Method Investments		64,323	68,309	64,323	68,309
Midstream energy services | Operating Segments
Operating Segment Financial Information [Line Items]
Operating Revenues	[1]	(25,801)	(15,869)	(17,997)	(21,938)
Depreciation and Amortization		31	31	93	93
Equity in Earnings of Unconsolidated Affiliates		718	85	1,865	355
EBIT		(26,607)	(16,806)	(23,343)	(29,410)
Total Assets		203,591	181,880	203,591	181,880
Capital Expenditures		85	0	85	0
Equity Method Investments		$ 56,967	$ 22,426	$ 56,967	$ 22,426
[1]	Operating revenues are reported gross of revenue taxes. Revenue taxes of both the regulated utility and the retail energy-marketing segments include gross receipt taxes. Revenue taxes of the regulated utility segment also include public service commission fees, franchise fees and energy taxes. Operating revenue amounts in the “Eliminations” row represent total intersegment revenues associated with sales from the regulated utility segment to the retail energy-marketing segment. Midstream Energy Services’ cost of energy related sales is netted with its gross revenues.
[2]	Intersegment eliminations include any mark-to market valuations associated with trading activities between WGL Midstream and WGL Energy Services, intercompany loans and a timing difference between Commercial Energy Systems’ recognition of revenue for the sale of Renewable Energy Credits (RECs) to Retail Energy-Marketing and Retail Energy-Marketing’s recognition of the associated expense. Retail Energy-Marketing has recorded a portion of the REC’s purchased as inventory to be used in future periods at which time they will be expensed.

Operating Segment (Details 2)

Operating Segment (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting [Abstract]
Total consolidated EBIT	$ (13,976)	$ (8,975)	$ 249,711	$ 130,064
Interest expense	13,140	9,503	38,704	28,020
INCOME (LOSS) BEFORE INCOME TAXES	(27,116)	(18,478)	211,007	102,044
Income tax expense (benefit)	(11,756)	(6,868)	80,364	33,152
NET INCOME (LOSS)	(15,360)	(11,610)	130,643	68,892
Dividends on Washington Gas Light Company preferred stock	330	330	990	990
NET INCOME (LOSS) APPLICABLE TO COMMON STOCK	$ (15,690)	$ (11,940)	$ 129,653	$ 67,902

Other Investments Narrative (De

Other Investments Narrative (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2015USD ($)MMBTUagreementcompanyinvestmentmi	Mar. 31, 2015	Mar. 10, 2015MMBTU	Sep. 30, 2014USD ($)
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Number of investments qualifying as variable interest entities | investment	4
Gain on sale of investments	$ 700
Investments in unconsolidated affiliates	121,290			$ 100,528
Investments in direct financing leases, capital leases	25,826			18,159
Impairment loss	$ 5,600
Meade
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Pipeline length in miles | mi	177
Transportation and delivery capacity in dekatherms per day | MMBTU	1,700,000
Estimated Investment in Meade	$ 412,000
Ownership percentage	55.00%
Investments in unconsolidated affiliates	$ 21,700			5,800
Maximum financial exposure	$ 59,400
Constitution
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	10.00%
Cash invested	$ 26,400
Investments in unconsolidated affiliates	29,500
Maximum financial exposure	26,400
Estimated investment In constitution	$ 79,000
Willams Partners L.P. | Constitution
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	41.00%
Cabot Oil And Gas Corporation | Constitution
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	25.00%
Piedmont Natural Gas | Constitution
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	24.00%
COG Holdings LLC | Meade
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	20.00%
Vega Midstream MPC LLC | Meade
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	15.00%
River Road Interests LLC | Meade
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership percentage	10.00%
Washington Gas Resources Corp. | American Solar Direct Holdings Inc. (ASDHI)
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost method investments				5,600
Impairment loss	$ 5,600
WGSW
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Investments in direct financing leases, capital leases	34,400
Residual value	7,700
Tax credits	2,600
Unearned income	15,600
Initial direct costs	700
WGSW | Sun Edison/Nextility
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Investments in direct financing leases, capital leases	29,100			19,900
Current investment recorded in accounts receivable	$ 3,300			1,700
Number of agreements | agreement	2
Number of Counterparties | company	2
WGSW | ASD Solar, LP
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Investments in unconsolidated affiliates	$ 64,300			$ 66,800
Difference between carrying amount and underlying equity	$ 35,900
WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Transportation and delivery capacity in dekatherms per day | MMBTU	2,000,000
Ownership percentage		7.00%
Investments in unconsolidated affiliates	$ 5,900
Pro rata share of project cost	$ 2,500
Mountain Valley Gas Purchase Commitment | WGL Midstream
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Transportation and delivery capacity in dekatherms per day | MMBTU			500,000
External Partners | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Ownership interest in joint venture after funding requirements are met	3.00%
External Partners | Minimum | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Maximum financial exposure	$ 96,000
External Partners | Maximum | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Maximum financial exposure	105,000
Scenario, Plan | Minimum | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Pro rata share of project cost	230,000
Scenario, Plan | Maximum | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Pro rata share of project cost	245,000
Performance guarantee | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Maximum financial exposure	20,000
Performance guarantee | WGL Midstream | WGL Midstream | Mountain Valley Pipeline
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Maximum financial exposure	$ 14,000

Other Investments Financing Lea

Other Investments Financing Leases Table (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2014
Minimum Payments Receivable for Direct Financing Leases
Total	$ 25,826	$ 18,159
WGSW
Minimum Payments Receivable for Direct Financing Leases
Remainder of 2015	2,400
2,016	2,500
2,017	2,400
2,018	2,300
2,019	2,200
Thereafter	22,600
Total	$ 34,400

Other Investments Balance Sheet

Other Investments Balance Sheet Location Table (Details) - USD ($) $ in Thousands	Jun. 30, 2015		Sep. 30, 2014
Assets [Abstract]
Investments in unconsolidated affiliates	$ 121,290		$ 100,528
Investments in direct financing leases, capital leases	25,826		18,159
VIEs
Assets [Abstract]
Investments in unconsolidated affiliates	85,900		72,600
Investments in direct financing leases, capital leases	25,800		18,200
Accounts receivable	3,300		1,700
Total assets	115,000		92,500
Non VIEs
Assets [Abstract]
Investments in unconsolidated affiliates	35,400		27,900
Investments in direct financing leases, capital leases	0		0
Accounts receivable	2,500	[1]	0
Total assets	37,900		27,900
Total
Assets [Abstract]
Investments in unconsolidated affiliates	121,300		100,500
Investments in direct financing leases, capital leases	25,800		18,200
Accounts receivable	5,800		1,700
Total assets	$ 152,900		$ 120,400
[1]	Represents the financing provided to another partner in Mountain Valley to fund its capital commitment. Acquired ownership interest represents the collateral for repayment of the financing.

Other Investments Income Statem

Other Investments Income Statement Location Table (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income (Loss) Attributable to Parent [Abstract]
Equity in earnings of unconsolidated affiliates	$ 1,262	$ 818	$ 4,238	$ 1,851
Other income (expenses)-net	2,329	(304)	(1,688)	257
NET INCOME (LOSS)	(15,360)	(11,610)	130,643	68,892
VIEs
Net Income (Loss) Attributable to Parent [Abstract]
Equity in earnings of unconsolidated affiliates	800	500	2,400	1,300
Depreciation and amortization	100	0	200	100
Other income (expenses)-net	1,000	600	2,400	1,900
NET INCOME (LOSS)	1,700	1,100	4,600	3,100
Non VIEs
Net Income (Loss) Attributable to Parent [Abstract]
Equity in earnings of unconsolidated affiliates	500	300	1,800	600
Depreciation and amortization	0	0	0	0
Other income (expenses)-net	0	0	(5,600)	0
NET INCOME (LOSS)	500	300	(3,800)	600
Total Other Investments
Net Income (Loss) Attributable to Parent [Abstract]
Equity in earnings of unconsolidated affiliates	1,300	800	4,200	1,900
Depreciation and amortization	100	0	200	100
Other income (expenses)-net	1,000	600	(3,200)	1,900
NET INCOME (LOSS)	$ 2,200	$ 1,400	$ 800	$ 3,700

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2014
Washington Gas Light Company
Related Party Transaction [Line Items]
Receivables from associated companies	$ 4,800		$ 4,800		$ 4,800
Payables to associated companies	66,900		66,900		54,700
WGL Energy Services | Washington Gas Light Company
Related Party Transaction [Line Items]
Accounts payable, related parties	7,000		7,000
Accounts receivable, related parties					20
Washington Gas Light Company
Related Party Transaction [Line Items]
Receivables from associated companies	4,838		4,838		4,821
Payables to associated companies	66,855		66,855		54,685
Washington Gas Light Company | WGL Energy Services
Related Party Transaction [Line Items]
Gas balancing service charge	5,300	$ 2,800	19,800	$ 21,000
Receivables purchased from related party	$ 21,200		$ 21,200		$ 7,700

Commitments and Contingencies61

Commitments and Contingencies (Narrative) (Details) $ in Millions	May. 12, 2015	May. 06, 2015USD ($)well	Jun. 30, 2015USD ($)	Mar. 10, 2015MMBTU	Nov. 30, 2014MMBTU
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation			$ 41,534.6
Virginia Gas Reserves
Commitments And Contingencies [Line Items]
Term of agreement		20 years
Number of wells | well		25
Cost of acquired non-operating working interest		$ 126
Decision period	180 days
WGL Midstream | GAIL Global (USA) LNG, LLC
Commitments And Contingencies [Line Items]
Gas sale and purchase and capacity agreement terms			20 years
WGL Midstream | Mountain Valley Gas Purchase Commitment
Commitments And Contingencies [Line Items]
Transportation and delivery capacity in dekatherms per day | MMBTU				500,000
Gas sale and purchase and capacity agreement terms			20 years
WGL Midstream | Minimum | GAIL Global (USA) LNG, LLC
Commitments And Contingencies [Line Items]
Transportation and delivery capacity in dekatherms per day | MMBTU					340,000
WGL Midstream | Maximum | GAIL Global (USA) LNG, LLC
Commitments And Contingencies [Line Items]
Transportation and delivery capacity in dekatherms per day | MMBTU					430,000
WGL | WGL Energy Services | Guarantee on behalf of subsidiary
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation			$ 224.8
WGL | WGL Midstream | Guarantee on behalf of subsidiary
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation			311.8
WGL | Other Subsidiaries | Guarantee on behalf of subsidiary
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation			9.1
WGL | External Partners | Performance guarantee
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation			$ 8.1

Commitments and Contingencies62

Commitments and Contingencies (Commitments) (Details) $ in Millions		Jun. 30, 2015USD ($)
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015		$ 218.7
2,016		845.9
2,017		638.3
2,018		1,277.5
2,019		1,811.3
Thereafter		36,742.9
Total		41,534.6
Washington Gas Light Company | Gas Purchase Commitments
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[1]	42.4
2,016	[1]	359.6
2,017	[1]	465.4
2,018	[1]	460.9
2,019	[1]	453.2
Thereafter	[1]	5,577.2
Total	[1]	7,358.7
Washington Gas Light Company | Pipeline Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[2]	55.4
2,016	[2]	218.7
2,017	[2]	210.5
2,018	[2]	211.3
2,019	[2]	202.7
Thereafter	[2]	1,172.5
Total	[2]	2,071.1
WGL Energy Services | Gas Purchase Commitments
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[3]	37.1
2,016	[3]	146.3
2,017	[3]	57.3
2,018	[3]	6.7
2,019	[3]	0
Thereafter	[3]	0
Total	[3]	247.4
WGL Energy Services | Pipeline Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[4]	1.5
2,016	[4]	2.2
2,017	[4]	2
2,018	[4]	1.5
2,019	[4]	0.8
Thereafter	[4]	1.7
Total	[4]	9.7
WGL Energy Services | Electric Purchase Commitments
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[5]	153.3
2,016	[5]	418.1
2,017	[5]	171.3
2,018	[5]	36.5
2,019	[5]	2
Thereafter	[5]	0.5
Total	[5]	781.7
Commitments related to renewable energy credits		18.2
WGL Midstream | Gas Purchase Commitments
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[6]	20.9
2,016	[6]	258.9
2,017	[6]	389.5
2,018	[6]	1,217.4
2,019	[6]	1,747.8
Thereafter	[6]	35,647.5
Total	[6]	39,282
WGL Midstream | Pipeline Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2015	[4]	5.9
2,016	[4]	20.4
2,017	[4]	18.2
2,018	[4]	15.4
2,019	[4]	60.7
Thereafter	[4]	1,093.2
Total	[4]	$ 1,213.8
[1]	Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on market prices at June 30, 2015.
[2]	Represents minimum payments for natural gas transportation, storage and peaking contracts that have expiration dates through fiscal year 2031.
[3]	Represents fixed price commitments with city gate equivalent deliveries.
[4]	Represents minimum payments for natural gas transportation and storage contracts that have expiration dates through fiscal year 2044.
[5]	Represents electric purchase commitments that are based on existing fixed price and fixed volume contracts. Includes $18.2 million of commitments related to renewable energy credits.
[6]	Includes known and reasonably likely commitments to purchase natural gas. Cost estimates are based on forward market prices as of June 30, 2015.

Pension and Other Post-Retire63

Pension and Other Post-Retirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3.9	$ 3.5	$ 11.6	$ 10.5
Interest cost	9.7	10.1	29.3	30.3
Expected return on plan assets	(11.2)	(10.2)	(33.5)	(30.7)
Amortization of prior service cost (credit)	0.1	0.1	0.2	0.2
Amortization of actuarial loss	4.7	4.2	14.1	12.6
Net periodic benefit cost	7.2	7.7	21.7	22.9
Amount allocated to construction projects	(1.2)	(1.1)	(3.4)	(3.1)
Amortization of regulatory asset (liability)-net	1.8	1.7	5.3	5.3
Amount charged (credited) to expense	7.8	8.3	23.6	25.1
Health and Life Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.8	1.6	5.3	5.9
Interest cost	3.7	3.8	11	14.8
Expected return on plan assets	(5.2)	(4.9)	(15.6)	(14.4)
Amortization of prior service cost (credit)	(3.8)	(3.8)	(11.4)	(5.8)
Amortization of actuarial loss	1.1	1.6	3.3	3.5
Net periodic benefit cost	(2.4)	(1.7)	(7.4)	4
Amount allocated to construction projects	0.5	0.1	1.5	(0.7)
Amortization of regulatory asset (liability)-net	(0.1)	0.2	(0.2)	0.4
Amount charged (credited) to expense	$ (2)	$ (1.4)	$ (6.1)	$ 3.7

Accumulated Other Comprehensi64

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance		$ (11,643)		$ (10,969)	$ (7,961)		$ (11,048)
Qualified cash flow hedging instruments	[1]	49		0	(7,994)		0
Change in prior service cost (credit)	[2]	(170)		6,204	(511)		6,135
Change in actuarial net loss	[2]	529		404	1,503		604
Current-period other comprehensive income		408		6,608	(7,002)		6,739
Income tax expense (benefit) related to other comprehensive income (loss)		163		2,622	(3,565)		2,674
Ending Balance		(11,398)		(6,983)	(11,398)		(6,983)
Washington Gas Light Company
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance		(6,031)		(10,969)	(6,413)		(11,048)
Change in prior service cost (credit)	[3]	(170)	[2]	6,204	(511)	[2]	6,135
Change in actuarial net loss	[3]	529	[2]	404	1,503	[2]	604
Current-period other comprehensive income		359		6,608	992		6,739
Income tax expense (benefit) related to other comprehensive income (loss)		143		2,622	394		2,674
Ending Balance		$ (5,815)		$ (6,983)	$ (5,815)		$ (6,983)
[1]	Cash flow hedging instruments represent interest rate swaps agreements on debt issuances. Refer to Note 8- Derivative and weather-related instruments for further discussion of the interest rate swap agreements.
[2]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14- Pension and other post-retirement benefit plans for additional details.
[3]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost. Refer to Note 14-Pension and other post-retirement benefit plans for additional details.