UIL (UIL) 10-Q 2 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 29, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	UIL HOLDINGS CORP
Entity Central Index Key	1,082,510
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		56,629,377
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015

CONSOLIDATED STATEMENT OF INCOM

CONSOLIDATED STATEMENT OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
CONSOLIDATED STATEMENT OF INCOME (Unaudited) [Abstract]
Operating Revenues	$ 330,524	$ 293,026	$ 1,226,584	$ 1,198,982
Operation
Purchased power	47,041	37,962	180,858	123,771
Natural gas purchased	26,313	30,814	240,934	322,296
Operation and maintenance	111,286	95,251	315,637	290,828
Transmission wholesale	30,272	25,802	67,969	65,777
Depreciation and amortization (Note F)	40,615	35,578	123,279	112,408
Taxes - other than income taxes (Note F)	35,196	32,897	108,345	102,974
Merger and acquisition-related expenses (Note A)	600	570	7,395	6,090
Total Operating Expenses	291,323	258,874	1,044,417	1,024,144
Operating Income	39,201	34,152	182,167	174,838
Other Income and (Deductions), net
Acquisition-related bridge facility fees (Note A)	0	(849)	0	(15,188)
Other income and (deductions) (Note F)	4,221	4,336	12,883	12,822
Total Other Income and (Deductions), net	4,221	3,487	12,883	(2,366)
Interest Charges, net
Interest on long-term debt	22,510	22,386	66,952	67,286
Other interest, net (Note F)	1,286	636	3,922	1,203
Interest charges, gross	23,796	23,022	70,874	68,489
Amortization of debt expense and redemption premiums	591	619	1,807	1,833
Total Interest Charges, net	24,387	23,641	72,681	70,322
Income from Equity Investments	3,408	3,492	10,284	10,398
Income Before Income Taxes	22,443	17,490	132,653	112,548
Income Taxes (Note E)	6,811	4,986	43,566	35,276
Net Income	15,632	12,504	89,087	77,272
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests	6	6	20	(21)
Net Income attributable to UIL Holdings	$ 15,626	$ 12,498	$ 89,067	$ 77,293
Average Number of Common Shares Outstanding - Basic (in shares)	57,150	56,855	57,120	56,827
Average Number of Common Shares Outstanding - Diluted (in shares)	57,438	57,133	57,420	57,114
Earnings Per Share of Common Stock - Basic (Note A) (in dollars per share)	$ 0.27	$ 0.22	$ 1.56	$ 1.36
Earnings Per Share of Common Stock - Diluted (Note A) (in dollars per share)	0.27	0.22	1.55	1.35
Cash Dividends Declared per share of Common Stock (in dollars per share)	$ 0.432	$ 0.432	$ 0.864	$ 1.296

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net Income	$ 15,632	$ 12,504	$ 89,087	$ 77,272
Other Comprehensive Income (Loss), net of income taxes
Changes in unrealized gains (losses) related to pension and other post-retirement benefit plans	(64)	(104)	(154)	126
Other	3	(6)	2	3
Total Other Comprehensive Income (Loss), net of income taxes	(61)	(110)	(152)	129
Comprehensive Income	15,571	12,394	88,935	77,401
Less:
Preferred Stock Dividends of Subsidiary, Noncontrolling Interests	6	6	20	(21)
Comprehensive Income Attributable to UIL Holdings	$ 15,565	$ 12,388	$ 88,915	$ 77,422

CONSOLIDATED BALANCE SHEET (Una

CONSOLIDATED BALANCE SHEET (Unaudited) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Current Assets
Unrestricted cash and temporary cash investments		$ 83,716	$ 115,579
Restricted cash		1,256	1,051
Accounts receivable less allowance of $8,406 and $10,481, respectively		216,165	232,887
Unbilled revenues		55,045	95,816
Current regulatory assets (Note A)		82,196	92,764
Natural gas in storage, at average cost		62,177	86,428
Refundable taxes		13,612	15,211
Current portion of derivative assets (Note A)		10,382	6,849
Prepayments		24,478	10,696
Other		13,640	12,815
Total Current Assets		562,667	670,096
Other investments
Equity investment in GenConn (Note A)		110,346	114,195
Other		27,709	25,777
Total Other investments		138,055	139,972
Net Property, Plant and Equipment (Note A)		3,485,452	3,292,690
Regulatory Assets (Note A)		683,297	687,198
Deferred Charges and Other Assets
Unamortized debt issuance expenses		12,610	13,571
Other long-term receivable		1,486	1,490
Derivative assets (Note A)		21,134	20,421
Goodwill		266,205	266,205
Other		1,460	20,292
Total Deferred Charges and Other Assets		302,895	321,979
Total Assets	[1]	5,172,366	5,111,935
Current Liabilities
Line of credit borrowings		85,000	89,000
Current portion of long-term debt		6,529	6,526
Accounts payable		141,845	217,700
Dividends payable		24,464	24,428
Accrued liabilities		68,381	71,182
Current regulatory liabilities (Note A)		21,969	17,026
Taxes accrued		19,856	20,184
Interest accrued		25,838	22,437
Deferred income taxes		12,716	3,767
Current portion of derivative liabilities (Note A)		28,206	23,308
Total Current Liabilities		434,804	495,558
Deferred Income Taxes		620,009	585,335
Regulatory Liabilities (Note A)		524,077	491,896
Other Noncurrent Liabilities
Pension accrued		264,317	265,009
Other post-retirement benefits accrued		86,684	85,777
Derivative liabilities (Note A)		74,752	61,766
Other		48,864	46,924
Total Other Noncurrent Liabilities		$ 474,617	$ 459,476
Commitments and Contingencies (Note J)
Capitalization (Note B)
Long-term debt, net of unamortized discount and premium		$ 1,730,306	$ 1,711,349
Preferred Stock, not subject to mandatory redemption		119	119
Common Stock Equity
Common stock		1,153,816	1,149,985
Paid-in capital		22,459	21,587
Retained earnings		212,590	196,907
Accumulated other comprehensive income (loss)		(431)	(277)
Net Common Stock Equity		1,388,434	1,368,202
Total Capitalization		3,118,859	3,079,670
Total Liabilities and Capitalization		$ 5,172,366	$ 5,111,935
[1]	Includes $266.2 million of goodwill in the Gas Distribution segment as of September 30, 2015 and December 31, 2014.

CONSOLIDATED BALANCE SHEET (Un5

CONSOLIDATED BALANCE SHEET (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current Assets
Allowance for doubtful accounts receivable	$ 8,406	$ 10,481

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Cash Flows From Operating Activities
Net income		$ 89,087	$ 77,272
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		125,086	114,241
Deferred income taxes		40,533	32,524
Allowance for funds used during construction (AFUDC) - equity		(6,698)	(6,869)
Stock-based compensation expense (Note A)		6,060	3,441
Pension expense		27,774	23,508
Undistributed (earnings) losses in equity investments		(10,284)	(9,801)
Regulatory activity, net		21,279	83,021
Other non-cash items, net		(956)	995
Changes in:
Accounts receivable, net		17,192	31,737
Unbilled revenues		40,771	37,856
Natural gas in storage		24,251	(2,484)
Prepayments		(13,782)	(8,391)
Cash distributions from GenConn		10,147	10,404
Accounts payable		(67,675)	(38,298)
Interest accrued		3,401	3,781
Taxes accrued/refundable, net		1,271	(11,483)
Accrued liabilities		(5,163)	11,080
Accrued pension		(24,182)	(32,422)
Accrued other post-employment benefits		(3,377)	(3,528)
Other assets		(1,101)	469
Other liabilities		2,714	6,500
Total Adjustments		187,261	246,281
Net Cash provided by Operating Activities		276,348	323,553
Cash Flows from Investing Activities
Plant expenditures including AFUDC debt	[1]	(254,197)	(196,171)
Acquisition of Milford LNG		0	(20,110)
Cash distributions from GenConn		3,981	3,927
Deposits in New England East West Solution (NEEWS) (Note C)		(1,451)	(5,068)
Investment in NED pipeline		(1,595)	0
Changes in restricted cash		(205)	395
Net Cash used in Investing Activities		(253,467)	(217,027)
Cash Flows from Financing Activities
Issuance of long-term debt		50,000	0
Payments on long-term debt		(27,500)	(10,000)
Line of credit borrowings (repayments), net		(4,000)	10,000
Payment of common stock dividend		(73,348)	(73,280)
Other		104	(288)
Net Cash used in Financing Activities		(54,744)	(73,568)
Unrestricted Cash and Temporary Cash Investments:
Net change for the period		(31,863)	32,958
Balance at beginning of period		115,579	69,153
Balance at end of period		83,716	102,111
Non-cash investing activity:
Plant expenditures included in ending accounts payable		28,557	18,461
Plant expenditures funded by deposits in NEEWS		(20,012)	0
Deposits in New England East West Solution (NEEWS)		$ 20,012	$ 0
[1]	Information for segmenting total capital expenditures between Distribution and Transmission is not available. Total Electric Distribution and Transmission capital expenditures are disclosed in the Total Electric Distribution and Transmission column.

BUSINESS ORGANIZATION AND STATE

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2015
BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES [Abstract]
BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES	(A) BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES UIL Holdings is headquartered in New Haven, Connecticut, where its senior management maintains offices and is responsible for overall planning, operating and financial functions. The primary business of UIL Holdings is ownership of its operating regulated utility businesses. The utility businesses consist of the electric distribution and transmission operations of The United Illuminating Company (UI) and the natural gas transportation, distribution and sales operations and The Berkshire Gas Company (Berkshire, and together with SCG and CNG, the Gas Companies). UI is also a party to a joint venture with certain affiliates of NRG Energy, Inc. (NRG affiliates) pursuant to which UI holds 50% of the membership interests in GCE Holding LLC, whose wholly owned subsidiary, GenConn Energy LLC (collectively with GCE Holding LLC, GenConn) operates peaking generation plants in Devon, Connecticut (GenConn Devon) and Middletown, Connecticut (GenConn Middletown). Basis of Presentation The financial statements of UIL Holdings are prepared on a consolidated basis and therefore include the accounts of UIL Holdings’ majority-owned subsidiaries noted above. Intercompany accounts and transactions have been eliminated in consolidation. The year‑end balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (GAAP). Certain information and footnote disclosures, which are normally included in financial statements prepared in accordance with GAAP, have been condensed or omitted in accordance with Securities and Exchange Commission (SEC) rules and regulations. We believe that the disclosures made are adequate to make the information presented not misleading. The information presented in the Consolidated Financial Statements reflects all adjustments which, in our opinion, are necessary for a fair statement of the financial position and results of operations for the interim periods described herein. All such adjustments are of a normal and recurring nature. The results for the three- and nine-month periods ended September 30, 2015 are not necessarily indicative of the results for the entire fiscal year ending December 31, 2015. Proposed Merger with Iberdrola USA On February 25, 2015, we announced that UIL Holdings had entered into a definitive merger agreement (the Agreement) with Iberdrola USA and its wholly-owned subsidiary, Green Merger Sub, Inc. (merger sub) under which Iberdrola USA will acquire UIL Holdings through a merger of UIL Holdings with and into merger sub and merger sub being the surviving corporation (the merger). Merger sub will change its name to UIL Holdings Corporation and remain a direct or indirect wholly-owned subsidiary of Iberdrola USA. Iberdrola USA will then become a newly listed U.S. publicly-traded company. In connection with the merger, each issued and outstanding share of the common stock of UIL Holdings will be converted into the right to receive one validly issued share of common stock of the newly listed company plus $10.50 in cash. Immediately following the consummation of the merger, former holders of UIL Holdings’ common stock will own approximately 18.5% of the newly listed company. The merger remains subject to certain closing conditions, including the approval of the shareowners of UIL Holdings and regulatory approvals from the Connecticut Public Utilities Regulatory Authority (PURA) and the Massachusetts Department of Public Utilities (DPU). All other regulatory approvals have been obtained. Iberdrola USA and UIL Holdings made the required filings at the PURA and the DPU seeking approval of the change in control on March 25, 2015. On July 7, 2015, in response to the issuance of a draft decision issued by PURA, UIL Holdings and Iberdrola USA filed a letter with PURA withdrawing their pending application and terminating the proceeding. On July 31, 2015, UIL Holdings and Iberdrola USA (including its related entities) filed a new application with PURA for approval of the change in control. On September 18, 2015, UIL Holdings, Iberdrola USA (including its related parties) and the Connecticut Office of Consumer Counsel (OCC) filed a settlement agreement with PURA that included various commitments in addition to those included in the July 31, 2015 application. Hearings have been completed and a draft decision is expected on November 24, 2015 with a final decision currently scheduled for December 9, 2015. On October 19, 2015, UIL Holdings and Iberdrola USA (including its related parties), the Attorney General of the Commonwealth of Massachusetts and the Massachusetts Department of Energy Resources (DOER) filed a settlement agreement with the DPU that supplements, modifies and supersedes the various commitments included in the March 25, 2015 application and August 6, 2015 updated testimony. The filing of the settlement agreement requests that the DPU approve the settlement agreement and authorize the merger by December 18, 2015. We currently expect that the merger will close promptly after satisfaction or waiver of all closing conditions, including receipt of shareowner approval and all regulatory approvals, and not later than December 31, 2015. There are no assurances that the merger will be consummated on the currently expected timetable or at all. Unless stated otherwise, all forward-looking information contained in this report does not take into account or give any effect to the impact of the proposed merger. For the three and nine months ended September 30, 2015, UIL Holdings incurred pre-tax merger-related expenses of approximately $0.6 Further information concerning the proposed merger is included Note (C) “Regulatory Proceedings” and in a proxy statement/prospectus contained in a registration statement on Form S-4, as amended, filed by Iberdrola USA with the SEC on July 17, 2015 in connection with the proposed merger. Philadelphia Gas Works In March 2014, UIL Holdings entered into an Asset Purchase Agreement (the Asset Purchase Agreement) with the City of Philadelphia pursuant to which UIL Holdings, through a wholly-owned subsidiary, was to acquire the operating assets and assume certain liabilities of Philadelphia Gas Works. The proposed acquisition was subject to the satisfaction or waiver of certain customary and other closing conditions for transactions of this type, including approval from the Philadelphia City Council. In light of the City Council’s October 2014 announcement to not endorse the proposed acquisition, we exercised our contractual right to terminate the Asset Purchase Agreement in December 2014. For the three and nine month periods ended September 30, 2014, UIL Holdings incurred pre-tax acquisition-related expenses of approximately $1.4 Derivatives UIL Holdings’ regulated subsidiaries are parties to contracts, and involved in transactions, that are derivatives. Contracts for Differences (CfDs) Pursuant to Connecticut’s 2005 Energy Independence Act, PURA solicited bids to create new or incremental capacity resources in order to reduce federally mandated congestion charges, and selected four new capacity resources. To facilitate the transactions between the selected capacity resources and Connecticut electric customers, and provide the commitment necessary for owners of these resources to obtain necessary financing, PURA required that UI and The Connecticut Light and Power Company (CL&P) execute long-term contracts with the selected resources. In August 2007, PURA approved four CfDs, each of which specifies a capacity quantity and a monthly settlement that reflects the difference between a forward market price and the contract price. UI executed two of the contracts and CL&P executed the other two contracts. The costs or benefits of each contract will be paid by or allocated to customers and will be subject to a cost-sharing agreement between UI and CL&P pursuant to which approximately 20% of the cost or benefit is borne by or allocated to UI customers and approximately 80% is borne by or allocated to CL&P customers. PURA has determined that costs associated with these CfDs will be fully recoverable by UI and CL&P through electric rates, and in accordance with ASC 980 “Regulated Operations,” UI has deferred recognition of costs (a regulatory asset) or obligations (a regulatory liability). The CfDs are marked-to-market in accordance with ASC 815 “Derivatives and Hedging.” For those CfDs signed by CL&P, UI records its approximate 20% portion pursuant to the cost-sharing agreement noted above. As of September 30, 2015, UI has recorded a gross derivative asset of $31.5 million ($1.3 million of which is related to UI’s portion of the CfD signed by CL&P), a regulatory asset of $72.0 million, a gross derivative liability of $102.9 million ($65.1 million of which is related to UI’s portion of the CfD signed by CL&P) and a regulatory liability of $0.6 million. See Note (K) “Fair Value of Financial Instruments” for additional CfD information. The gross derivative assets and liabilities as of September 30, 2015 and December 31, 2014 were as follows: September 30, 2015 December 31, 2014 (In Thousands) Gross derivative assets: Current Assets $ 10,382 $ 6,849 Deferred Charges and Other Assets $ 21,134 $ 20,421 Gross derivative liabilities: Current Liabilities $ 28,206 $ 23,308 Noncurrent Liabilities $ 74,752 $ 61,766 The unrealized gains and losses from fair value adjustments to these derivatives, which are recorded in regulatory assets or regulatory liabilities, for the three- and nine-month periods ended September 30, 2015 and 2014 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands) (In Thousands) Regulatory Assets - Derivative liabilities $ (3,206 ) $ 393 $ 7,751 $ (81,623 ) Regulatory Liabilities - Derivative assets $ 313 $ 5,077 $ 5,886 $ (6,616 ) The fluctuations in the balances of the derivatives as well as the related unrealized gains in the three- and nine-month periods ended September 30, 2015 compared to the three- and nine-month periods ended September 30, 2014 are primarily due to fluctuations in forward prices for capacity and reserves. Weather Insurance Contracts On an annual basis, SCG and Berkshire each assess the need for weather insurance contracts for the upcoming heating season in order to provide financial protection from significant weather fluctuations. According to the terms of such contracts, if temperatures are warmer than normal at a prescribed level for the contract period, a payment is received by the gas company. The premiums paid are amortized over the terms of the contracts. The intrinsic value of the contracts is carried on the balance sheet with changes in value recorded in the income statement as Other Income and (Deductions). As a result of PURA’s approval of a decoupling mechanism for CNG which went into effect in January 2014, CNG does not enter into weather insurance contracts. In September 2015, SCG and Berkshire entered into weather insurance contracts for the winter period of November 1, 2015 through April 30, 2016. If temperatures are warmer than normal, SCG and Berkshire will receive payments up to a maximum of $3 million and $1 million, respectively. Earnings per Share The following table presents a reconciliation of the basic and diluted earnings per share calculations for the three‑ and nine-month periods ended September 30, 2015 and 2014: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands, except per share amounts) Numerator: Net income attributable to UIL Holdings $ 15,626 $ 12,498 $ 89,067 $ 77,293 Less: Net income allocated to unvested units 7 7 44 45 Net income attributable to common shareholders $ 15,619 $ 12,491 $ 89,023 $ 77,248 Denominator: Basic average number of shares outstanding 57,150 56,855 57,120 56,827 Effect of dilutive securities (1) 288 278 300 287 Diluted average number of shares outstanding 57,438 57,133 57,420 57,114 Earnings per share: Basic $ 0.27 $ 0.22 $ 1.56 $ 1.36 Diluted $ 0.27 $ 0.22 $ 1.55 $ 1.35 (1) Includes unvested restricted stock and performance shares. Equity and Other Investments UI is party to a 50-50 joint venture with the NRG affiliates in GenConn, which operates two peaking generation plants in Connecticut. UI’s investment in GenConn is being accounted for as an equity investment, the carrying value of which was $110.3 million and $114.2 million as of September 30, 2015 and December 31, 2014, respectively. As of September 30, 2015, there was $0.1 million of undistributed earnings from UI’s equity investment in GenConn. UI’s pre-tax income from its equity investment in GenConn was $3.4 million and $3.5 million for the September 30, 2015 and 2014, respectively. UI’s pre-tax income from its equity investment in GenConn for each of the nine-month periods ending September 30, 2015 and 2014 was $10.3 million and $10.4 million. Cash distributions from GenConn are reflected as either distributions of earnings or as returns of capital in the operating and investing sections of the Consolidated Statement of Cash Flows, respectively. UI received cash distributions from GenConn of $6.0 million and $5.5 million in the September 30, 2015 and 2014, respectively. UI received cash distributions from GenConn of $14.1 million and $14.3 million in the September 30, 2015, respectively and 2014. On July 24, 2015, UIL Holdings announced its participation in Tennessee Gas Pipeline Company LLC’s (TGP) proposed Northeast Energy Direct project (NED pipeline) through an acquisition of a 2.5% equity interest in Northeast Expansion LLC. Northeast Expansion LLC is a joint venture between an affiliate of Kinder Morgan, Inc., (Kinder Morgan) and Liberty Utilities (Pipeline & Transmission) Corp, which will construct and own the NED pipeline, a new, “market path” natural gas pipeline segment of approximately 188 miles from Wright, New York, to Dracut, Massachusetts. This 2.5% equity interest, which totaled approximately $1.6 million as of September 30, 2015, commits UIL Holdings to an initial capital investment opportunity that is expected to total up to approximately $80 million, depending on the final pipeline configuration and design capacity. Pursuant to an option agreement with Kinder Morgan, UIL Holdings also has the option to acquire up to an additional 12.5% of equity interests in Northeast Expansion LLC under certain limited circumstances, including if certain additional firm transportation agreements for service on the NED pipeline are entered into or if TGP does not sell additional volume on the NED pipeline. Any increase in equity ownership would increase UIL Holdings’ investment commitment proportionately. In addition, as a condition to making this investment, UIL Holdings entered into a 20-year Precedent Agreement with TGP for pipeline capacity of 70,000 Dekatherms/day on the NED pipeline, which capacity commitment, under the terms of the Precedent Agreement, would be reduced in the event that TGP enters into additional precedent agreements with third parties for capacity on the NED pipeline. Regulatory Accounting Unless otherwise stated below, all of our regulatory assets earn a return. Our regulatory assets and liabilities as of September 30, 2015 and December 31, 2014 included the following: Remaining Period September 30, 2015 December 31, 2014 (In Thousands) Regulatory Assets: Unamortized redemption costs 7 to 19 years $ 9,897 $ 10,499 Pension and other post-retirement benefit plans (a) 395,356 402,700 Environmental remediation costs 7 years 14,461 13,197 Hardship programs (b) 19,625 24,744 Debt premium 2 to 23 years 23,694 27,498 Income taxes due principally to book-tax differences (c) 168,093 164,466 Unfunded future income taxes (d) 17,722 14,859 Contracts for differences (e) 72,027 64,276 Deferred transmission expense (f) 7,620 17,387 Other (g) 36,998 40,336 Total regulatory assets 765,493 779,962 Less current portion of regulatory assets 82,196 92,764 Regulatory Assets, Net $ 683,297 $ 687,198 Regulatory Liabilities: Accumulated deferred investment tax credits 29 years $ 7,245 $ 4,319 Excess generation service charge (h) 35,827 28,692 Middletown/Norwalk local transmission network service collections 35 years 20,398 20,828 Pension and other post-retirement benefit plans (a) 10,026 9,536 Asset retirement obligation (i) 7,061 7,248 Low income programs (j) 30,098 19,065 Asset removal costs (i) 357,099 336,028 Unfunded future income taxes (d) 25,991 26,318 Contracts for differences (e) 586 6,472 Deferred purchased gas (k) 638 4,736 Non-firm margin sharing credits 9 years 13,044 8,933 Other (g) 38,033 36,747 Total regulatory liabilities 546,046 508,922 Less current portion of regulatory liabilities 21,969 17,026 Regulatory Liabilities, Net $ 524,077 $ 491,896 (a) Life is dependent upon timing of final pension plan distribution; balance, which is fully offset by a corresponding asset/liability, is recalculated each year in accordance with ASC 715 "Compensation-Retirement Benefits." See Note (G) “Pension and Other Benefits” for additional information. (b) Hardship customer accounts deferred for future recovery to the extent they exceed the amount in rates. (c) Amortization period and/or balance vary depending on the nature and/or remaining life of the underlying assets/liabilities. (d) The balance will be extinguished when the asset, which is fully offset by a corresponding liability, or liability has been realized or settled, respectively. (e) Asset life is equal to delivery term of related contracts (which vary from approximately 5 - 12 years); balance fluctuates based upon quarterly market analysis performed on the related derivatives (Note K); amount, which does not earn a return, is fully offset by corresponding derivative asset/liability. See “-Contracts for Differences” discussion above for additional information. (f) Regulatory asset or liability which defers transmission income or expense and fluctuates based upon actual revenues and revenue requirements. (g) Amortization period and/or balance vary depending on the nature, cost of removal and/or remaining life of the underlying assets/liabilities; asset amount includes certain amounts that are not currently earning a return; September 30, 2015 liability amount includes decoupling of $18.9 million. (h) Regulatory asset or liability which defers generation-related and nonbypassable federally mandated congestion costs or revenues for future recovery from or return to customers. Amount fluctuates based upon timing differences between revenues collected from rates and actual costs incurred. (i) The liability will be extinguished simultaneous with the retirement of the assets and settlement of the corresponding asset retirement obligation. (j) Various hardship and payment plan programs approved for recovery. (k) Deferred purchased gas costs balances at the end of the rate year are normally recorded/returned in the next year. Stock-Based Compensation Pursuant to the UIL Holdings 2008 Stock and Incentive Compensation Plan (2008 Stock Plan), 94,410 restricted stock units were granted to certain members of management in March 2015; the average of the high and low market prices on the grant date, which approximate fair value, was $49.72 per share. Also in March 2015, we granted a total of 1,584 shares of restricted stock to our President and Chief Executive Officer under the 2008 Stock Plan and in accordance with his employment agreement; the average of the high and low market price on the date of grant, which approximates fair value, was $49.72 per share. Such shares vest in equal annual installments over a five-year period. In May 2015, UIL Holdings granted a total of 18,801 shares of restricted stock to non-employee directors under the 2008 Stock Plan; the average of the high and low market price on the date of grant, which approximates fair value, was $48.37 per share. Such shares vest in May 2016. Total stock-based compensation expense for the three-month periods ended September 30, 2015 and 2014 September 30, 2015 and 2014 Variable Interest Entities We have identified GenConn as a variable interest entity (VIE), which is accounted for under the equity method. UIL Holdings is not the primary beneficiary of GenConn, as defined in ASC 810 “Consolidation,” because it shares control of all significant activities of GenConn with its joint venturer, NRG affiliates. As such, GenConn is not subject to consolidation. GenConn recovers its costs through CfDs, which are cost of service-based and have been approved by PURA. As a result, with the achievement of commercial operation by GenConn Devon and GenConn Middletown, our exposure to loss is primarily related to the potential for unrecovered GenConn operating or future capital costs in a regulatory proceeding, the effect of which would be reflected in the carrying value of our 50% ownership position in GenConn and through “Income from Equity Investments” in UIL Holdings’ Consolidated Financial Statements. We have identified the selected capacity resources with which UI has CfDs as VIEs and have concluded that UI is not the primary beneficiary as UI does not have the power to direct any of the significant activities of these capacity resources. As such, we have not consolidated the selected capacity resources. UI’s maximum exposure to loss through these agreements is limited to the settlement amount under the CfDs as described in “–Derivatives – Contracts for Differences (CfDs)” above; however any such losses are fully recoverable through electric rates. UI has no requirement to absorb additional losses nor has UI provided any financial or other support during the periods presented that were not previously contractually required. We have identified the entities for which UI is required to enter into long-term contracts to purchase Renewable Energy Credits (RECs) as VIEs. In assessing these contracts for VIE identification and reporting purposes, we have aggregated the contracts based on similar risk characteristics and significance to UI. UI is not the primary beneficiary as UI does not have the power to direct any of the significant activities of these entities. UI’s exposure to loss is primarily related to the purchase and resale of the RECs, but, any losses incurred are recoverable through electric rates. For further discussion of RECs, see Note (C) “Regulatory Proceedings – Electric Distribution and Transmission – New Renewable Source Generation.” New Accounting Pronouncements In August 2015, the FASB issued Accounting Standards Update (ASU) 2015-13, “Derivatives and Hedging” which specifies that the use of locational marginal pricing by an independent system operator does not constitute net settlement of a forward contract for the purchase or sale of electricity and does not cause that contract to fail to meet the physical delivery criterion of the normal purchases and normal sales scope exception. This guidance was effective upon issuance and does have an impact on UIL Holdings’ consolidated financial statements. In August 2015, the FASB issued Accounting Standards Update (ASU) 2015-14, “Revenue from Contracts with Customers” which defers the effective date of ASU 2014-09 by one year. ASU 2014-09 requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. We are currently evaluating the effect that adopting this new accounting guidance will have on our consolidated financial statements. Also in August 2015, the FASB issued Accounting Standards Update (ASU) 2015-15, “Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements” which incorporates SEC guidance into ASC 835 “Interest” that allows an entity to defer and present debt issuance costs related to line of credit arrangements as an asset and subsequently amortize such costs ratably over the term of the arrangement regardless of whether there are any outstanding borrowings on the line of credit. This guidance is not expected to be material to UIL Holdings’ consolidated financial statements. In July 2015, the FASB issued Accounting Standards Update (ASU) 2015-11, “Inventory – Simplifying the Measurement of Inventory” which requires inventory that is measured using first-in, first-out or average cost methods to be measured using the lower of cost and net realizable value. ASU 2015-11 is effective for interim and annual reporting periods beginning after December 15, 2016 and is to be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. This is not expected to be material to UIL Holdings’ consolidated financial statements. In April 2015, the FASB issued Accounting Standards Update (ASU) 2015-03, “Interest—Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs” which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is effective for interim and annual reporting periods beginning after December 15, 2015 and is to be applied retrospectively. Adopting this new accounting guidance will reduce both Deferred Charges and Other Assets and Long-term debt on the consolidated balance sheet. This effect is not expected to be material to UIL Holdings’ consolidated financial statements.

CAPITALIZATION

CAPITALIZATION	9 Months Ended
	Sep. 30, 2015
CAPITALIZATION [Abstract]
CAPITALIZATION	(B) CAPITALIZATION Common Stock UIL Holdings had 56,629,377 shares of its common stock, no par value, outstanding at September 30, 2015 Long-term Debt On June 29, 2015, UI issued $50 million of its 4.61% Senior Notes, Series G, due June 29, 2045. UI used the net proceeds from this long-term debt issuance to re-pay $27.5 million of pollution control refunding revenue bonds which were subject to mandatory purchase on July 1, 2015 and plans on using the remaining funds for general corporate purposes or other purposes described in its application to PURA for approval of the issuance of debt and as approved by PURA.

REGULATORY PROCEEDINGS

REGULATORY PROCEEDINGS	9 Months Ended
	Sep. 30, 2015
REGULATORY PROCEEDINGS [Abstract]
REGULATORY PROCEEDINGS	(C) REGULATORY PROCEEDINGS Proposed Merger with Iberdrola USA As discussed in Note A “Organization and Statement of Accounting Policies”, on February 25, 2015 we announced that UIL Holdings had entered into a the Agreement with Iberdrola USA and merger sub under which Iberdrola USA will acquire UIL Holdings through a merger of UIL Holdings with and into merger sub and merger sub being the surviving corporation. The merger remains subject to certain closing conditions, including the approval of the shareowners of UIL Holdings and regulatory approval from PURA and the DPU. Iberdrola USA and UIL Holdings made the required filings at the PURA and the DPU seeking approval of the change in control on March 25, 2015. On July 7, 2015, in response to the issuance of a draft decision issued by PURA, UIL Holdings and Iberdrola USA filed a letter with PURA withdrawing their pending application and terminating the proceeding. On July 31, 2015, Iberdrola USA (and its related entities) and UIL Holdings filed a new application with PURA for approval of the change in control. The new application includes commitments and identifies public interest benefits to meet the statutory requirements in Connecticut for approval of a change in control. The commitments include rate credits to customers (approximately $20 million), a distribution rate freeze to 2018 for SCG and CNG, and to 2017 for UI, commitments to contribute to a clean energy fund and disaster relief (together, approximately $7 million), accelerated capital investment in electric distribution system resiliency and gas distribution system replacement of cast iron and bare steel (delayed recovery in rates resulting in nearly $7 million). In addition, in the new application the companies commit to no change in the day-to-day management and operation of UIL Holdings’ three Connecticut utilities, to hiring 150 employees or contractors within the State of Connecticut over the next three years, to maintain UI’s high service reliability and CNG and SCG’s high levels of gas leak response, and to improve The new application also proposes comprehensive “ring fencing” provisions to protect the Connecticut utilities from involuntary bankruptcy associated with potential future adverse changes in financial circumstances of Iberdrola affiliates. These provisions include the creation of a special purpose entity with at least one independent director, dividend limitations on the Connecticut utilities where the investment grade credit rating is in jeopardy or if a minimum common equity ratio is not maintained, commitments to maintain separate books and records and a prohibition on commingling of funds. The new application also included an agreement to negotiate a consent order with DEEP to remediate the English Station site in New Haven, Connecticut, formerly owned by UI. On September 16, 2015, UI signed a Proposed Partial Consent Order that, when issued by the Commissioner of DEEP, and subject to the closing of the merger and other terms and conditions in the Proposed Partial Consent Order, would require UI to investigate and remediate certain environmental conditions within the perimeter of the English Station site. Under the Proposed Partial Consent Order, to the extent that the cost of this investigation and remediation of the English Station site is less than $30 million, UI will remit to the State of Connecticut the difference between such cost and $30 million to be used for a public purpose as determined in the discretion of the Governor of the State of Connecticut, the Attorney General of the State of Connecticut, and the Commissioner of DEEP. Pursuant to the Proposed Partial Consent Order, upon its issuance and subject to its terms and conditions, UI is obligated to comply with the Proposed Partial Consent Order, even if the cost On September 18, 2015, UIL Holdings, Iberdrola USA (including its related parties) and the OCC filed a settlement agreement with PURA that included various commitments in addition to those included in the July 31, 2015 application. The settlement agreement includes $12.5 million in additional rate credits for CNG’s customers and $7.5 million in additional rate credits for SCG’s customers, both of which would be allocated over the ten-year period of 2018 – 2027. As part of the settlement, both OCC and UI will also withdraw their respective appeals of certain PURA decisions that are currently pending. Hearings have been completed and a draft decision is expected on November 24, 2015 with a final decision is currently scheduled for December 9, 2015. On October 19, 2015, UIL Holdings and Iberdrola USA (including its related parties), the Attorney General of the Commonwealth of Massachusetts and the Massachusetts Department of Energy Resources (DOER) filed a settlement agreement with the DPU that supplements, modifies and supersedes the various commitments included in the March 25, 2015 application and August 6, 2015 updated testimony. The settlement agreement includes $4 million in rate credits for Berkshire customers and $1 million for jobs, economic development, or alternative heating programs for municipal owned buildings, low-income and moderate income residential consumers, or residences or businesses in Berkshire’s service territory, as determined by DOER. The settlement agreement also includes a distribution rate freeze for Berkshire, such that current distribution rates for Berkshire remain in effect, with no new distribution base rates in effect prior to June 1, 2018. The settlement agreement includes similar local management, ring-fencing and economic commitments to those that were offered in the settlement agreement filed with PURA in Connecticut. The filing of the settlement agreement requests that the DPU approve the settlement agreement and authorize the merger by December 18, 2015. Electric Distribution and Transmission Rates Utilities are entitled by Connecticut statutes to charge rates that are sufficient to allow them an opportunity to cover their reasonable operating and capital costs, to attract needed capital and to maintain their financial integrity, while also protecting relevant public interests. UI’s allowed distribution return on equity established by PURA is 9.15%. UI is required to return to customers 50% of any distribution earnings over the allowed ROE in a calendar year by means of an earnings sharing mechanism. Power Supply Arrangements UI has wholesale power supply agreements in place for its entire standard service load for 2015, 80% of its standard service load for the first half of 2016 and 30% of the standard serve load for the second half of 2016. Supplier of last resort service is procured on a quarterly basis, however, from time to time there are no bidders in the procurement process for supplier of last resort service and in such cases UI manages the load directly. UI determined that its contracts for standard service and supplier of last resort service are derivatives under ASC 815 “Derivatives and Hedging” and elected the “normal purchase, normal sale” exception under ASC 815 “Derivatives and Hedging.” UI regularly assesses the accounting treatment for its power supply contracts. These wholesale power supply agreements contain default provisions that include required performance assurance, including certain collateral obligations, in the event that UI’s credit rating on senior debt were to fall below investment grade. If UI’s credit rating were to decline one rating at Standard & Poor’s or two ratings at Moody’s and UI were to be placed on negative credit watch, monthly amounts due and payable to the power suppliers would be accelerated to semi-monthly payments. UI’s credit rating would have to decline two ratings at Standard & Poor’s and three ratings at Moody’s to fall below investment grade. If this were to occur, UI would have to deliver collateral security in an amount equal to the receivables due to the sellers for the thirty-day period immediately preceding the default notice. If such an event had occurred as of September 30, 2015 New Renewable Source Generation Pursuant to Connecticut law (PA 13-303), on September 19, 2013, at the direction of the Connecticut Department of Energy and Environmental Protection, (DEEP), UI entered into two contracts for energy and/or RECs from Class I renewable resources, totaling approximately 3.5% of UI’s distribution load, which were subsequently approved by PURA. Costs of each of these agreements will be fully recoverable through electric rates. On December 18, 2013, Allco Finance Limited, an unsuccessful bidder for such contracts, filed a complaint against DEEP in the United States District Court in Connecticut alleging that DEEP’s direction to UI and CL&P to enter into the contracts violated the Supremacy Clause of the U.S. Constitution and the Federal Power Act by setting wholesale electricity rates. This complaint was dismissed in December 2014. On January 2, 2015 Allco filed an appeal with the United States Court of Appeals for the Second Circuit. Transmission PURA decisions do not affect the revenue requirements determination for UI’s transmission business, including the applicable return on equity (ROE), which is within the jurisdiction of the FERC. For 2015, UI is estimating an overall allowed weighted-average ROE for its transmission business in the range of 11.3% to 11.4%. This includes the impact of the FERC orders issued in 2014 and 2015, and excludes any impacts of the reserve adjustment, both of which are discussed below. Beginning in 2011, several New England state attorneys general, state regulatory commissions, consumer advocates, consumer groups, municipal parties and other parties filed three separate complaints with the FERC against ISO-NE and several New England transmission owners, including UI. In the first complaint, filed in September 2011, the complainants claimed that the then current approved base ROE of 11.14% used in calculating formula rates for transmission service under the ISO-NE Open Access Transmission Tariff by the New England transmission owners was not just and reasonable and sought a reduction of the base ROE and a refund to customers for a refund period of October 1, 2011 through December 31, 2012. In 2012 and 2014, respectively, the complainants filed claims with the FERC similarly challenging the base ROE and seeking refunds for the 15-month periods beginning December 27, 2012 and July 31, 2014, respectively. The complainants in the third complaint also asked for a determination that the top of the zone of reasonableness caps the ROE for each individual project. The FERC issued an order consolidating the second and third complaints and establishing hearing procedures. The New England transmission owners petitioned FERC for a rehearing, which was denied in May 2015. Hearings were held in June 2015 on the second and third complaints before a FERC Administrative Law Judge, relating to the refund periods and going forward. On July 29, 2015, post-hearing briefs were filed by parties and on August 26, 2015 reply briefs were filed by parties. An initial decision by the Administrative Law Judge is expected by December 31, 2015. On July 13, 2015, the New England transmission owners filed a petition for review of FERC’s orders establishing hearing and consolidation procedures for the second and third complaints with the U.S. Court of Appeals. In 2014, the FERC determined that the base ROE should be set at 10.57% for the first complaint refund period and that a utility's total or maximum ROE should not exceed 11.74%. The FERC ordered the New England transmission owners to provide refunds to customers for the first complaint refund period and set the new base ROE of 10.57% prospectively from October 16, 2014. On March 3, 2015, the FERC issued an Order on Rehearing in the first complaint (the March Order) denying all rehearing requests from the complainants and the New England transmission owners. On April 30, 2015, the New England transmission owners filed a petition for review of the FERC’s decisions on the first complaint with the U.S. Court of Appeals for the D.C. Circuit. On May 1, 2015, two additional petitions for review of those FERC decisions were also filed at the D.C. Circuit by the complainants and by several customers. The appeals of the FERC’s decisions on the first complaint have been consolidated and are currently pending before the D.C. Circuit. UI recorded additional pre-tax reserves of $3.4 million in the first nine months of 2015 relating to the third complaint and the March Order. As of September 30, 2015, net pre-tax reserves relating to refunds and potential refunds to customers under all three claims were approximately $5.1 million and cumulative pre-tax reserves were approximately $11.5 million, of which $6.4 million has already been refunded to customers. New England East-West Solution Pursuant to which was fully energized in November 2013, t (IRP), which is expected to be placed in service in December 2015 the Central Connecticut Reliability Project (CCRP), which was reassessed as part of Study (GHCC). Under the terms of the Agreement, UI has the option to make quarterly deposits to CL&P in exchange for ownership of specific NEEWS transmission assets as they are placed in service. UI has the right to invest up to the greater of $60 million or an amount equal to 8.4% of CL&P’s costs for the originally proposed Connecticut portions of the NEEWS projects. Based upon the current projected costs, UI’s investment rights in GSRP and IRP is approximately $45 million. In February 2015, ISO-NE issued its final GHCC transmission solutions report and, in March 2015, approved the proposed plan applications. Based on the ISO-NE reassessment of CCRP and the currently planned generation in Connecticut, UI does not anticipate making any investments in GHCC or further investment in NEEWS. Deposits associated with NEEWS are recorded as assets at the time the deposit is made and they are reported in the ‘Other’ line item within the Deferred Charges and Other Assets section of the consolidated balance sheet. When title to the assets is transferred to UI, the amount of the corresponding deposit is reclassified from other assets to plant-in-service on the balance sheet and shown as a non-cash investing activity in the consolidated statement of cash flows. As of September 30, 2015 associated with the GSRP September 30, 2015 and 2014 September 30, 2015 and 2014 Other Proceedings On November 12, 2014, PURA issued a decision in a docket addressing UI’s semi-annual Generation Services Charge (GSC), bypassable federally mandated congestion charge and the non-bypassable federally mandated congestion charge (NBFMCC) reconciliations. PURA’s decision allowed for recovery of $7.7 million of the $11.3 million request included in UI’s filing for the reconciliation of certain revenues and expenses relating to the period from 2004 through 2013. This resulted in UI recording a pre-tax write-off of approximately $3.8 million during the fourth quarter of 2014, which amount included the disallowed portion of UI’s request as well as additional 2014 carrying charges. Also on November 12, 2014, PURA issued a final decision in UI’s final Competitive Transition Assessment (CTA) reconciliation proceeding which extinguished all remaining CTA balances. In addition, the final decision allowed for the application of an approximate $8.2 million remaining CTA regulatory liability, as well as an approximate $12.0 million regulatory liability related to the Connecticut Yankee Atomic Power Company litigation against the U.S. Department of Energy (DOE), against UI’s storm regulatory asset balance. The final decision required that remaining regulatory liability balance be applied to the GSC “working capital allowance” and be returned to customers through the NBFMCC. Because the two decisions noted above, among other things, fail to apply rate making principles on a consistent basis, UI filed appeals with the State of Connecticut Superior Court in December 2014 for both the GSC/NBFMCC and the CTA final decisions. On February 3, 2015, PURA filed a motion to dismiss UI’s appeal of the CTA final decision. On June 17, 2015, the Superior Court denied PURA’s motion to dismiss the CTA appeal. UI filed a motion to stay the appeals in the two proceedings discussed above in connection with the settlement agreement filed with PURA in the change in control proceeding. On October 12, 2015, the motions to stay were granted. Upon PURA’s acceptance of the settlement agreement, such proceedings would be terminated. Gas Distribution Rates Utilities are entitled by Connecticut and Massachusetts statutes to charge rates that are sufficient to allow them an opportunity to cover their reasonable operating and capital costs, to attract needed capital and to maintain their financial integrity, while also protecting relevant public interests. The allowed returns on equity established by PURA are 9.18% and 9.36% for CNG and SCG, respectively. Berkshire’s rates are established by the DPU. Berkshire’s 10-year rate plan, which was approved by the DPU and included an approved ROE of 10.5%, expired on January 31, 2012. Berkshire continues to charge the rates that were in effect at the end of the rate plan. Based on existing tracking mechanisms in place for gas and other costs, discussions with the DPU, and precedence set by other utility companies, Berkshire believes that regulatory assets are recoverable and regulatory liabilities are fairly stated. SCG and CNG each have purchased gas adjustment clauses and Berkshire has a cost of gas adjustment clause, approved by PURA and DPU, respectively, which enable them to pass their reasonably incurred cost of gas purchases through to customers. These clauses allow utilities to recover costs associated with changes in the market price of purchased natural gas, substantially eliminating exposure to natural gas price risk. Additionally, Berkshire’s mechanism allows for the recovery of the gas-cost portion of bad debt. On January 22, 2014, PURA approved new base delivery rates for CNG, with an effective date of January 10, 2014, which, among other things, approved an allowed ROE of 9.18%, a decoupling mechanism, and two separate ratemaking mechanisms that reconcile actual revenue requirements related to CNG’s cast iron and bare steel replacement program and system expansion. Additionally, the final decision requires the establishment of an earnings sharing mechanism by which CNG and customers share on a 50/50 basis all earnings above the allowed ROE in a calendar year. The decision also allows CNG, on a provisional basis, to reflect the increased rate base resulting from the accumulated deferred income tax (ADIT) impacts of the election of Section 338(h)(10) of the Internal Revenue Code upon its acquisition by UIL Holdings. The decision requires CNG to seek a private letter ruling from the Internal Revenue Service with regard to the specific question of whether, after extinguishment of an ADIT balance, a directive by a public utility commission to institute a ratemaking mechanism to reflect a credit to ratepayers of ADIT benefits lost through a Section 338(h)(10) election would result in a normalization violation. The decision states that in the event of a ruling from the Internal Revenue Service stating that imposing such a ratemaking mechanism would not create a normalization violation, PURA would adjust rates to offset the ratemaking impacts of the 338(h)(10) election on rate base. We estimate the impact to be an approximate $2.5 to $3.5 million decrease in annual revenue requirements. In March 2014, CNG filed a draft of its private letter ruling request with PURA for approval upon which PURA subsequently issued comments. During the first quarter of 2014, the OCC appealed PURA’s decision to the Connecticut Superior Court with regard to the establishment of an adjustment mechanism for incremental cast iron and bare steel replacement as well as PURA’s directive to seek a private letter ruling with respect to the extinguishment of ADITs rather than ordering a rate credit to hold customers harmless from the ratemaking effect of extinguishing the ADITs. At the request of PURA, the OCC and CNG engaged in settlement discussions regarding the appeal. Settlement discussions have now terminated. In connection with the settlement agreement filed with PURA in our change in control proceeding, CNG filed a motion with PURA to extend the due date for CNG’s response to PURA’s comments on the private letter ruling to November 24, 2015. The OCC filed a motion to stay the appeal discussed above in connection with the settlement agreement filed with PURA in our change in control proceeding. On August 31, 2015, the motion to stay was granted. Upon PURA’s acceptance of the settlement agreement, the proceeding would be terminated. Other Proceedings As discussed above, CNG’s 2013 rate proceeding provides for a decoupling mechanism as well as a rate making mechanism related to its cast iron and bare steel replacement program. Additionally, a comprehensive joint 10-year natural gas expansion plan (“Expansion Plan”) filed jointly by CNG, SCG and Yankee Gas Services Company in response to the gas expansion goals proposed in the Connecticut Governor’s Comprehensive Energy Strategy and Public Act 13-298 and approved by PURA includes a new business reconciliation mechanism that reconciles the actual new business revenue requirements each year with the revenues received from the new business customers. The initial filings for these mechanisms are discussed below. On March 2, 2015, CNG filed its initial decoupling adjustment which includes a $10.8 million credit to customers, which will be credited on customers’ bills during the period of April 1, 2015 through March 31, 2016. On March 20, 2015, SCG and CNG filed their initial System Expansion (SE) Rate reconciliation for 2014. The proposed SE rate was approved by PURA for implementation as of April 1, 2015, pending final PURA approval following a contested hearing. On April 1, 2015, CNG filed its initial Distribution Integrity Management Program (DIMP) reconciliation filing, which reconciles actual revenue requirements related to CNG’s cast iron and bare steel replacement program. The proposed DIMP rate was approved by PURA for implementation as of May 1, 2015.

SHORT-TERM CREDIT ARRANGEMENTS

SHORT-TERM CREDIT ARRANGEMENTS	9 Months Ended
	Sep. 30, 2015
SHORT-TERM CREDIT ARRANGEMENTS [Abstract]
SHORT-TERM CREDIT ARRANGEMENTS	(D) SHORT‑TERM CREDIT ARRANGEMENTS As of September 30, 2015, there was $85 million in borrowings outstanding under the existing revolving credit agreement among UIL Holdings, certain of its subsidiaries and a group of banks that expires on November 30, 2016 (the UIL Holdings Credit Facility) UIL Holdings UIL Holdings UIL Holdings UIL Holdings

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2015
INCOME TAXES [Abstract]
INCOME TAXES	(E) INCOME TAXES The significant portion of UIL Holdings’ income tax expense, including deferred taxes, is recovered through its regulated subsidiaries’ utility rates. UIL Holdings’ annual income tax expense and associated effective tax rate is impacted by differences in the treatment of certain transactions for book and tax purposes and by differences between the timing of deferred tax temporary difference activity and deferred tax recovery. In accordance with ASC 740, we use an estimated annual effective tax rate approach to calculate interim period income tax expense for ordinary income. We also record separate income tax effects for significant unusual or infrequent items. UIL Holdings’ income tax expense increased by $1.8 million, from $5.0 million in the third quarter of 2014 to $6.8 million in the third quarter of 2015. The increase was primarily attributable to higher pre-tax earnings. UIL Holdings’ income tax expense increased $8.3 million, from $35.3 million in the first nine months of 2014 to $43.6 million in the first nine months of 2015. The increase was primarily attributable to higher pre-tax earnings due mainly to the absence in 2015 of acquisition bridge facility fees. The annualized effective income tax rate for both nine-month periods ended September 30, 2015 and 2014 was 32.9%. The Internal Revenue Service completed its examination of UIL Holdings’ income tax years 2009 through 2012, resulting in the effective settlement of these tax years and the recording of an additional $1.1 million in tax expense during the second quarter of 2015.

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION	9 Months Ended
	Sep. 30, 2015
SUPPLEMENTARY INFORMATION [Abstract]
SUPPLEMENTARY INFORMATION	(F) SUPPLEMENTARY INFORMATION Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands) (In Thousands) Depreciation and Amortization Property, plant, and equipment depreciation $ 37,081 $ 32,860 $ 106,185 $ 97,208 Amortization of regulatory assets 3,534 2,718 17,094 15,200 Total Depreciation and Amortization $ 40,615 $ 35,578 $ 123,279 $ 112,408 Taxes - Other than Income Taxes Operating: Connecticut gross earnings $ 18,180 $ 16,199 $ 56,353 $ 54,671 Local real estate and personal property 14,085 13,310 40,080 37,399 Payroll taxes 2,886 3,046 11,064 9,877 Other 45 342 848 1,027 Total Taxes - Other than Income Taxes $ 35,196 $ 32,897 $ 108,345 $ 102,974 Other Income and (Deductions) Interest income $ 77 $ 666 $ 1,458 $ 1,731 Allowance for funds used during construction - equity 2,589 1,949 6,698 6,869 Allowance for funds used during construction - debt 1,292 1,201 3,424 4,032 Weather insurance - - - (2,437 ) Other 263 520 1,303 2,627 Total Other Income and (Deductions) $ 4,221 $ 4,336 $ 12,883 $ 12,822

PENSION AND OTHER BENEFITS

PENSION AND OTHER BENEFITS	9 Months Ended
	Sep. 30, 2015
PENSION AND OTHER BENEFITS [Abstract]
PENSION AND OTHER BENEFITS	(G) PENSION AND OTHER BENEFITS During the nine months ended September 30, 2015, we made pension contributions of $15 million. No further contributions are expected during the remainder of 2015. The following tables represent the components of net periodic benefit cost for pension and other postretirement benefits as well as the actuarial weighted-average assumptions used in calculating net periodic benefit cost for the three-and nine‑month periods ended : Three Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 (In Thousands) Components of net periodic benefit cost: Service cost $ 3,605 $ 2,896 $ 393 $ 404 Interest cost 10,505 11,019 1,327 1,487 Expected return on plan assets (14,120 ) (13,560 ) (690 ) (700 ) Amortization of prior service costs 48 73 75 71 Amortization of actuarial (gain) loss 4,845 3,097 176 (172 ) Net periodic benefit cost $ 4,883 $ 3,525 $ 1,281 $ 1,090 Nine Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 (In Thousands) Components of net periodic benefit cost: Service cost $ 10,815 $ 8,688 $ 1,179 $ 1,212 Interest cost 31,515 33,057 3,981 4,461 Expected return on plan assets (42,360 ) (40,680 ) (2,070 ) (2,100 ) Amortization of prior service costs 144 219 225 213 Amortization of actuarial (gain) loss 14,535 9,291 528 (516 ) Net periodic benefit cost $ 14,649 $ 10,575 $ 3,843 $ 3,270 Three and Nine Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.20%-4.30 % 4.90%-5.20 % 4.20%-4.30 % 4.85%-5.20 % Average wage increase 3.50%-3.80 % 3.50%-3.80 % N/A N/A Return on plan assets 7.75%-8.00 % 7.75%-8.00 % 5.56%-8.00 % 5.56%-8.00 % Composite health care trend rate (current year) N/A N/A 7.00 % 7.00 % Composite health care trend rate (2019 forward) N/A N/A 5.00 % 5.00 % N/A – not applicable

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2015
RELATED PARTY TRANSACTIONS [Abstract]
RELATED PARTY TRANSACTIONS	(H) RELATED PARTY TRANSACTIONS A Director of UIL Holdings holds a beneficial interest in the building located at 157 Church Street, New Haven, Connecticut, where UIL Holdings leases office space.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2015
COMMITMENTS AND CONTINGENCIES [Abstract]
COMMITMENTS AND CONTINGENCIES	(J) COMMITMENTS AND CONTINGENCIES In the ordinary course of business, we are involved in various proceedings, including legal, tax, regulatory and environmental matters, which require management’s assessment to determine the probability of whether a loss will occur and, if probable, an estimate of probable loss. When assessments indicate that it is probable that a liability has been incurred and an amount can be reasonably estimated, we accrue a reserve and disclose the reserve and related matter. We disclose material matters when losses are probable but for which an estimate cannot be reasonably estimated or when losses are not probable but are reasonably possible. Subsequent analysis is performed on a periodic basis to assess the impact of any changes in events or circumstances and any resulting need to adjust existing reserves or record additional reserves. However, given the inherent unpredictability of these legal and regulatory proceedings, we cannot assure you that our assessment of such proceedings will reflect the ultimate outcome, and an adverse outcome in certain matters could have a material adverse effect on our results of operations or cash flows. Connecticut Yankee Atomic Power Company UI has a 9.5% stock ownership share in the Connecticut Yankee Atomic Power Company, an inactive nuclear generating company (Connecticut Yankee), the carrying value of which was $0.2 million as of September 30, 2015. Connecticut Yankee has completed the physical decommissioning of its generation facilities and is now engaged primarily in the long-term storage of its spent nuclear fuel. Connecticut Yankee collects its costs through wholesale FERC-approved rates from UI and several other New England utilities. UI recovers these costs from its customers through electric rates. DOE Spent Fuel Litigation In 1998, Connecticut Yankee filed claims in the United States Court of Federal Claims seeking damages resulting from the breach of the 1983 spent fuel and high level waste disposal contract between Connecticut Yankee and the DOE. In September 2010, the court issued its decision and awarded Connecticut Yankee damages of $39.7 million for its spent fuel-related costs through 2001, which was affirmed in In December 2007, Connecticut Yankee filed a second set of complaints with the United States Court of Federal Claims against the DOE seeking damages incurred since January 1, 2002 for the DOE’s failure to remove Connecticut Yankee’s spent fuel. In November 2013, the court issued a final judgment, which was not appealed, awarding Connecticut Yankee damages of $126.3 million. In light of its ownership share, in September 2014, UI received approximately $12.0 million of such award which was applied, in part, against the remaining storm regulatory asset balance. The remaining regulatory liability balance was applied to the GSC “working capital allowance” and will be returned to customers through the nonbypassable federally mandated congestion charge. See Note (C) “Regulatory Proceedings – Electric Distribution and Transmission – Other Proceedings” for additional information. In August 2013, Connecticut Yankee filed a third set of complaints with the United States Court of Federal Claims against the DOE seeking an unspecified amount of damages incurred since January 1, 2009 for the DOE’s failure to remove Connecticut Yankee’s spent fuel. In April 2015, Connecticut Yankee provided the DOE with a third set of damage claims totaling approximately $32.9 million for damages incurred from January 1, 2009 through December 31, 2012. UI’s 9.5% ownership share would result in a receipt of approximately $3.1 million which, if awarded, would be refunded to customers. Environmental Matters In complying with existing environmental statutes and regulations and further developments in areas of environmental concern, including legislation and studies in the fields of water quality, hazardous waste handling and disposal, toxic substances, climate change and electric and magnetic fields, we may incur substantial capital expenditures for equipment modifications and additions, monitoring equipment and recording devices, as well as additional operating expenses. The total amount of these expenditures is not now determinable. Environmental damage claims may also arise from the operations of our subsidiaries. Significant environmental issues known to us at this time are described below. Site Decontamination, Demolition and Remediation Costs In January 2012, Evergreen Power, LLC (Evergreen Power) and Asnat Realty LLC (Asnat), then and current owners of a former generation site on the Mill River in New Haven (the “English Station site”) that UI sold to Quinnipiac Energy in 2000, filed a lawsuit in federal district court in Connecticut against UI seeking, among other things: (i) an order directing UI to reimburse the plaintiffs for costs they have incurred and will incur for the testing, investigation and remediation of hazardous substances at the English Station site and (ii) an order directing UI to investigate and remediate the site. In December 2013, Evergreen and Asnat filed a subsequent lawsuit in Connecticut state court seeking among other things: (i) remediation of the property; (ii) reimbursement of remediation costs; (iii) termination of UI’s easement rights; (iv) reimbursement for costs associated with securing the property; and (v) punitive damages. UI believes the claims are without merit. These lawsuits were stayed pending the disposition of mediation efforts involving the parties and certain claims relating to the English Station site. Management cannot presently assess the potential financial impact, if any, of the pending lawsuits. UI has not recorded a liability related to it. On April 8, 2013, DEEP issued an administrative order addressed to UI, Evergreen Power, Asnat and others, ordering the parties to take certain actions related to investigating and remediating the English Station site. Mediation of the matter began in the fourth quarter of 2013 and concluded unsuccessfully in April of 2015. Hearings on the administrative order are expected to take place in late February and early March 2016. On September 16, 2015, UI signed a Proposed Partial Consent Order that, when issued by the Commissioner of DEEP, and subject to the closing of the merger of UIL Holdings with Iberdrola USA and other terms and conditions in the Proposed Partial Consent Order, would require UI to investigate and remediate certain environmental conditions within the perimeter of the English Station site. Under the Proposed Partial Consent Order, to the extent that the cost of this investigation and remediation is less than $30 million, UI will remit to the State of Connecticut the difference between such cost and $30 million to be used for a public purpose as determined in the discretion of the Governor of the State of Connecticut, the Attorney General of the State of Connecticut, and the Commissioner of DEEP. Pursuant to the Proposed Partial Consent Order, upon its issuance and subject to its terms and conditions, UI would be obligated to comply with the Proposed Partial Consent Order, even if the cost of such compliance exceeds $30 million. The State will discuss options with UI on recovering or funding any cost above $30 million such as through public funding or recovery from third parties, however it is not bound to agree to or support any means of recovery or funding. On September 30, 2015, the Hearing Officer in DEEP’s administrative proceeding approved a Motion for Stay of further proceedings filed by DEEP, staying all proceedings on the administrative order for 120 days. A status conference is scheduled for January 28, 2016. With respect to transmission-related property adjacent to the New Haven Harbor Generating Station, UI performed an environmental analysis that indicated remediation expenses would be approximately $3.2 million. UI has accrued these estimated expenses, which were recovered in transmission rates. The Gas Companies own or have previously owned properties where Manufactured Gas Plants (MGPs) had historically operated and are contaminated as a result of MGP-related activities. Under existing regulations, the cleanup of such sites requires state and at times, federal, regulators’ involvement and approval in advance of commencement of any required cleanup. In certain cases, such contamination has been evaluated, characterized and remediated. In other cases, the sites have been evaluated and characterized, but not yet remediated. Finally, at some of these sites, the scope of the contamination has not yet been fully characterized; no liability was recorded in respect of these sites as of September 30, 2015 and no amount of loss, if any, can be reasonably estimated at this time SCG owns properties on Housatonic Avenue in Bridgeport, Connecticut and on Chapel Street in New Haven, Connecticut, and CNG owns a property located on Columbus Boulevard in Hartford, Connecticut, all of which are former MGP sites. Costs associated with the remediation of the sites, which will likely be subject to regulators’ approval, could be significant and these costs will be subject to a review by PURA as to whether these costs are recoverable in rates. Regarding the Chapel Street property, on October 7, 2015, SCG received a Proposed Consent Order from DEEP. SCG is presently reviewing this draft consent order, which, if issued by DEEP, would require the completion of investigation and then the development and implementation of a remedial action plan for the Chapel Street property. We cannot presently reasonably estimate the costs or range of costs of remediation or the likelihood of recoverability for these former MGP sites, including the Chapel Street property. As a result, as of , we have not recorded any liabilities related to these properties. Berkshire owns property on Mill Street in Greenfield, Massachusetts, a former MGP site. We estimate that expenses will likely amount to approximately $0.9 million and have recorded a liability and offsetting regulatory asset for such expenses as of . Historically, Berkshire formerly owned a site on East Street (the East Street Site) in Pittsfield, Massachusetts, a former MGP site which was sold to the General Electric Company (GE) in the 1970s. We reached a settlement with GE which provides, among other things, a framework for Berkshire and GE to allocate various monitoring and remediation costs at the East Street Site. As of , we had accrued approximately $3.2 million and established a regulatory asset for these and future . Historically, Middletown/Norwalk Transmission Project The general contractor responsible for civil construction work in connection with the installation of UI’s portion of the Middletown/Norwalk Transmission Project’s underground electric cable system filed a lawsuit in Connecticut state court on September 22, 2009. On September 3, 2013, the court found for UI on all claims but one related to certain change orders, and ordered UI to pay the general contractor approximately $1.3 million, which has since been paid. expects to recover any amounts paid to resolve the contractor and subcontractor claims through UI’s transmission revenue requirements. In April 2013, an affiliate of the general contractor for the Middletown/Norwalk Transmission Project, purporting to act as a shareholder on behalf of UIL Holdings, filed a complaint against the UIL Holdings Board of Directors alleging that the directors breached a fiduciary duty by failing to undertake an independent investigation in response to a letter from the affiliate asking for an investigation regarding alleged improper practices by UI in connection with the Middletown/Norwalk Transmission Project. In October 2013, the court granted the defendants’ motion to dismiss the complaint, which dismissal was affirmed by the Connecticut Appellate Court in March 2015. The period to file a petition for review by the Connecticut Supreme Court has passed and the case is now concluded.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2015
FAIR VALUE MEASUREMENTS [Abstract]
FAIR VALUE MEASUREMENTS	(K) FAIR VALUE MEASUREMENTS As required by ASC 820 “Fair Value Measurements and Disclosures,” financial assets and liabilities are classified in their entirety, based on the lowest level of 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 the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The following tables set forth the fair value of our financial assets and liabilities, other than pension benefits and other postretirement benefits, as of September 30, 2015 and December 31, 2014. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2015 (In Thousands) Assets: Derivative assets $ - $ - 31,516 $ 31,516 Noncurrent investments 13,141 - - 13,141 Deferred Compensation Plan 3,529 - - 3,529 Supplemental retirement benefit trust life insurance policies - 8,254 - 8,254 $ 16,670 $ 8,254 $ 31,516 $ 56,440 Liabilities: Derivative liabilities $ - $ - $ 102,958 $ 102,958 Long-term debt - 1,908,931 - 1,908,931 $ - $ 1,908,931 $ 102,958 $ 2,011,889 Net fair value assets/(liabilities), September 30, 2015 $ 16,670 $ (1,900,677 ) $ (71,442 ) $ (1,955,449 ) December 31, 2014 Assets: Derivative assets $ - $ - $ 27,270 $ 27,270 Noncurrent investments 11,387 - - 11,387 Deferred Compensation Plan 3,624 - - 3,624 Supplemental retirement benefit trust life insurance policies - 8,498 - 8,498 $ 15,011 $ 8,498 $ 27,270 $ 50,779 Liabilities: Derivative liabilities $ - $ - $ 85,074 $ 85,074 Long-term debt - 1,941,711 - 1,941,711 $ - $ 1,941,711 $ 85,074 $ 2,026,785 Net fair value assets/(liabilities), December 31, 2014 $ 15,011 $ (1,933,213 ) $ (57,804 ) $ (1,976,006 ) Fair value measurements categorized in Level 3 of the fair value hierarchy are prepared by individuals with expertise in valuation techniques, pricing of energy and energy-related products, and accounting requirements. The derivative assets consist primarily of CfDs. The determination of fair value of the CfDs was based on a probability-based expected cash flow analysis that was discounted at the September 30, 2015 or December 31, 2014 risk-free interest rates, as applicable, and an adjustment for non-performance risk using credit default swap rates. Certain management assumptions were required, including development of pricing that extended over the term of the contracts. We believe this methodology provides the most reasonable estimates of the amount of future discounted cash flows associated with the CfDs. Additionally, on a quarterly basis, we perform analytics to ensure that the fair value of the derivatives is consistent with changes, if any, in the various fair value model inputs. Additional quantitative information about Level 3 fair value measurements is as follows: Unobservable Input Range at Range at Contracts for differences Risk of non-performance 0.31% - 0.94 % 0.00% - 0.66 % Discount rate 1.37% - 2.06 % 1.65% - 2.25 % Forward pricing ($ per MW) $ 3.15 - $11.19 $ 3.15 - $14.59 The fair value of the noncurrent investments is determined using quoted market prices in active markets for identical assets. The investments primarily consist of money market funds. Under the UIL Deferred Compensation Plan (DCP), directors, named executive officers and certain other executives may elect to defer certain elements of compensation. Participants in the DCP are permitted to direct investments of their elective deferral accounts into “deemed” investments consisting of mutual funds and UIL Holdings common stock equivalents, with the exception of long-term incentive plan deferrals which are required to be invested in UIL Holdings common stock equivalents. These investments, which are actively traded in sufficient frequency and volume to provide pricing information on an ongoing basis, are marked-to-market based upon such pricing information. The determination of the fair value of the supplemental retirement benefit trust life insurance policies was based on quoted prices as of September 30, 2015 and December 31, 2014 in the active markets for the various funds within which the assets are held. Long-term debt is carried at cost on the consolidated balance sheet. The fair value of long-term debt as displayed in the table above is based on evaluated prices that reflect significant observable market information such as reported trades, actual trade information of similar securities, benchmark yields, broker/dealer quotes of new issue prices and relevant credit information. The following tables set forth a reconciliation of changes in the fair value of the assets and liabilities above that are classified as Level 3 in the fair value hierarchy for the nine-month period ended September 30, 2015. Nine Months Ended (In Thousands) Net derivative assets/(liabilities), December 31, 2014 $ (57,804 ) Unrealized gains and (losses), net (13,638 ) Net derivative assets/(liabilities), September 30, 2015 $ (71,442 ) Change in unrealized gains (losses), net relating to net derivative assets/(liabilities), still held as of September 30, 2015 $ (13,638 ) The following table sets forth a reconciliation of changes in the net regulatory asset/ (liability) balances that were established to recover any unrealized gains/(losses) associated with the CfDs for the nine-month period ended September 30, 2015. The amounts offset the net CfDs liabilities included in the derivative liabilities detailed above. Nine Months Ended (In Thousands) Net regulatory assets/(liabilities), December 31, 2014 $ 57,804 Unrealized (gains) and losses, net 13,638 Net regulatory assets/(liabilities), September 30, 2015 $ 71,442

SEGMENT INFORMATION

SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2015
SEGMENT INFORMATION [Abstract]
SEGMENT INFORMATION	(M) SEGMENT INFORMATION UIL Holdings is organized into Electric Distribution, Electric Transmission and Gas Distribution reporting segments based on several factors including, but not limited to, the nature of each segment’s products and services, the sources of operating revenues and expenses and the regulatory environment in which each segment operates. The following measures of segment profit and loss are utilized by management to make decisions about allocating resources to the segments and assessing performance. The following table reconciles certain segment information with that provided in our Consolidated Financial Statements. In the table, distribution includes all electric utility revenue and expenses except for transmission, which is provided in a separate column. “Other” includes the information for the remainder of our non‑utility activities and unallocated corporate costs, including minority interest investments and administrative costs. Revenues from inter‑segment transactions are not material. All of our revenues are derived in the United States. (In Thousands) Three months ended September 30, 2015 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 158,587 $ 77,767 $ 236,354 $ 94,170 $ - $ 330,524 Purchased power and gas 47,041 - 47,041 27,715 (1,402 ) 73,354 Operation and maintenance 55,394 14,838 70,232 47,805 (6,751 ) 111,286 Transmission wholesale - 30,272 30,272 - - 30,272 Depreciation and amortization 13,554 4,475 18,029 17,285 5,301 40,615 Taxes - other than income taxes 14,721 11,680 26,401 8,509 286 35,196 Merger and acquisition-related expenses - - - - 600 600 Operating Income 27,877 16,502 44,379 (7,144 ) 1,966 39,201 Other Income and (Deductions), net 1,682 375 2,057 1,594 570 4,221 Interest Charges, net 8,789 3,086 11,875 6,723 5,789 24,387 Income from Equity Investments 3,408 - 3,408 - - 3,408 Income (Loss) Before Income Taxes 24,178 13,791 37,969 (12,273 ) (3,253 ) 22,443 Income Taxes 6,032 5,374 11,406 (4,862 ) 267 6,811 Net Income (Loss) 18,146 8,417 26,563 (7,411 ) (3,520 ) 15,632 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 6 - 6 Net Income (Loss) attributable to UIL Holdings $ 18,146 $ 8,417 $ 26,563 $ (7,417 ) $ (3,520 ) $ 15,626 Total Capital Expenditures (1) $ - $ - $ 41,466 $ 39,744 $ 13,818 $ 95,028 Three months ended September 30, 2014 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 134,289 $ 62,926 $ 197,215 $ 94,708 $ 1,103 $ 293,026 Purchased power and gas 37,962 - 37,962 30,504 310 68,776 Operation and maintenance 42,819 11,456 54,275 44,950 (3,974 ) 95,251 Transmission wholesale - 25,802 25,802 - - 25,802 Depreciation and amortization 11,943 4,208 16,151 16,477 2,950 35,578 Taxes - other than income taxes 14,244 10,441 24,685 9,082 (870 ) 32,897 Merger and Acquisition-related expenses - - - - 570 570 Operating Income 27,321 11,019 38,340 (6,305 ) 2,117 34,152 Other Income and (Deductions), net 2,877 881 3,758 702 (973 ) 3,487 Interest Charges, net 7,590 3,375 10,965 7,116 5,560 23,641 Income from Equity Investments 3,492 - 3,492 - - 3,492 Income (Loss) Before Income Taxes 26,100 8,525 34,625 (12,719 ) (4,416 ) 17,490 Income Taxes 8,173 3,048 11,221 (6,229 ) (6 ) 4,986 Net Income (Loss) 17,927 5,477 23,404 (6,490 ) (4,410 ) 12,504 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 6 - 6 Net Income (Loss) attributable to UIL Holdings $ 17,927 $ 5,477 $ 23,404 $ (6,496 ) $ (4,410 ) $ 12,498 Total Capital Expenditures (1) $ - $ - $ 31,523 $ 32,926 $ 6,181 $ 70,630 (In Thousands) Nine months ended September 30, 2015 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 481,278 $ 195,481 $ 676,759 $ 549,825 $ - $ 1,226,584 Purchased power and gas 180,858 - 180,858 244,732 (3,798 ) 421,792 Operation and maintenance 152,747 42,415 195,162 137,590 (17,115 ) 315,637 Transmission wholesale - 67,969 67,969 - - 67,969 Depreciation and amortization 40,678 13,036 53,714 57,545 12,020 123,279 Taxes - other than income taxes 42,963 28,216 71,179 36,271 895 108,345 Merger and acquisition-related expenses - - - - 7,395 7,395 Operating Income 64,032 43,845 107,877 73,687 603 182,167 Other Income and (Deductions), net 5,591 2,925 8,516 2,617 1,750 12,883 Interest Charges, net 24,979 9,852 34,831 20,405 17,445 72,681 Income from Equity Investments 10,284 - 10,284 - - 10,284 Income (Loss) Before Income Taxes 54,928 36,918 91,846 55,899 (15,092 ) 132,653 Income Taxes 14,980 14,228 29,208 20,651 (6,293 ) 43,566 Net Income (Loss) 39,948 22,690 62,638 35,248 (8,799 ) 89,087 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 20 - 20 Net Income (Loss) attributable to UIL Holdings $ 39,948 $ 22,690 $ 62,638 $ 35,228 $ (8,799 ) $ 89,067 Total Capital Expenditures (1) $ - $ - $ 119,677 $ 93,094 $ 41,426 $ 254,197 Nine months ended September 30, 2014 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 397,384 $ 183,715 $ 581,099 $ 616,780 $ 1,103 $ 1,198,982 Purchased power and gas 123,771 - 123,771 321,986 310 446,067 Operation and maintenance 135,282 36,049 171,331 130,761 (11,264 ) 290,828 Transmission wholesale - 65,777 65,777 - - 65,777 Depreciation and amortization 35,902 12,635 48,537 55,994 7,877 112,408 Taxes - other than income taxes 38,597 26,832 65,429 37,080 465 102,974 Merger and acquisition-related expenses - - - - 6,090 6,090 Operating Income 63,832 42,422 106,254 70,959 (2,375 ) 174,838 Other Income and (Deductions), net 9,503 2,793 12,296 (587 ) (14,075 ) (2,366 ) Interest Charges, net 22,661 9,832 32,493 21,320 16,509 70,322 Income from Equity Investments 10,398 - 10,398 - - 10,398 Income (Loss) Before Income Taxes 61,072 35,383 96,455 49,052 (32,959 ) 112,548 Income Taxes 18,015 12,262 30,277 18,749 (13,750 ) 35,276 Net Income (Loss) 43,057 23,121 66,178 30,303 (19,209 ) 77,272 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - (21 ) - (21 ) Net Income (Loss) attributable to UIL Holdings $ 43,057 $ 23,121 $ 66,178 $ 30,324 $ (19,209 ) $ 77,293 Total Capital Expenditures (1) $ - $ - $ 91,600 $ 78,278 $ 26,293 $ 196,171 Electric Distribution and Transmission (2) Distribution Transmission Total Gas Distribution (3) Other Total (3) Total Assets at September 30, 2015 $ - $ - $ 2,930,013 $ 2,069,913 $ 172,440 $ 5,172,366 Total Assets at December 31, 2014 $ - $ - $ 2,876,792 $ 2,087,284 $ 147,859 $ 5,111,935 (1) Information for segmenting total capital expenditures between Distribution and Transmission is not available. Total Electric Distribution and Transmission capital expenditures are disclosed in the Total Electric Distribution and Transmission column. (2) Information for segmenting total assets between Distribution and Transmission is not available. Total Electric Distribution and Transmission assets are disclosed in the Total Electric and Distribution and Transmission column. Net plant in service is segregated by segment and, as of September 30, 2015, was $1,343.4 million and $699.7 million for Distribution and Transmission, respectively. As of December 31, 2014, net plant in service was $1,283.6 million and $659.4 million for Distribution and Transmission, respectively. (3) Includes $266.2 million of goodwill in the Gas Distribution segment as of September 30, 2015 and December 31, 2014.

BUSINESS ORGANIZATION AND STA18

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2015
BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES [Abstract]
Basis of Presentation	Basis of Presentation The financial statements of UIL Holdings are prepared on a consolidated basis and therefore include the accounts of UIL Holdings’ majority-owned subsidiaries noted above. Intercompany accounts and transactions have been eliminated in consolidation. The year‑end balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (GAAP). Certain information and footnote disclosures, which are normally included in financial statements prepared in accordance with GAAP, have been condensed or omitted in accordance with Securities and Exchange Commission (SEC) rules and regulations. We believe that the disclosures made are adequate to make the information presented not misleading. The information presented in the Consolidated Financial Statements reflects all adjustments which, in our opinion, are necessary for a fair statement of the financial position and results of operations for the interim periods described herein. All such adjustments are of a normal and recurring nature. The results for the three- and nine-month periods ended September 30, 2015 are not necessarily indicative of the results for the entire fiscal year ending December 31, 2015.
Business Combinations	Proposed Merger with Iberdrola USA On February 25, 2015, we announced that UIL Holdings had entered into a definitive merger agreement (the Agreement) with Iberdrola USA and its wholly-owned subsidiary, Green Merger Sub, Inc. (merger sub) under which Iberdrola USA will acquire UIL Holdings through a merger of UIL Holdings with and into merger sub and merger sub being the surviving corporation (the merger). Merger sub will change its name to UIL Holdings Corporation and remain a direct or indirect wholly-owned subsidiary of Iberdrola USA. Iberdrola USA will then become a newly listed U.S. publicly-traded company. In connection with the merger, each issued and outstanding share of the common stock of UIL Holdings will be converted into the right to receive one validly issued share of common stock of the newly listed company plus $10.50 in cash. Immediately following the consummation of the merger, former holders of UIL Holdings’ common stock will own approximately 18.5% of the newly listed company. The merger remains subject to certain closing conditions, including the approval of the shareowners of UIL Holdings and regulatory approvals from the Connecticut Public Utilities Regulatory Authority (PURA) and the Massachusetts Department of Public Utilities (DPU). All other regulatory approvals have been obtained. Iberdrola USA and UIL Holdings made the required filings at the PURA and the DPU seeking approval of the change in control on March 25, 2015. On July 7, 2015, in response to the issuance of a draft decision issued by PURA, UIL Holdings and Iberdrola USA filed a letter with PURA withdrawing their pending application and terminating the proceeding. On July 31, 2015, UIL Holdings and Iberdrola USA (including its related entities) filed a new application with PURA for approval of the change in control. On September 18, 2015, UIL Holdings, Iberdrola USA (including its related parties) and the Connecticut Office of Consumer Counsel (OCC) filed a settlement agreement with PURA that included various commitments in addition to those included in the July 31, 2015 application. Hearings have been completed and a draft decision is expected on November 24, 2015 with a final decision currently scheduled for December 9, 2015. On October 19, 2015, UIL Holdings and Iberdrola USA (including its related parties), the Attorney General of the Commonwealth of Massachusetts and the Massachusetts Department of Energy Resources (DOER) filed a settlement agreement with the DPU that supplements, modifies and supersedes the various commitments included in the March 25, 2015 application and August 6, 2015 updated testimony. The filing of the settlement agreement requests that the DPU approve the settlement agreement and authorize the merger by December 18, 2015. We currently expect that the merger will close promptly after satisfaction or waiver of all closing conditions, including receipt of shareowner approval and all regulatory approvals, and not later than December 31, 2015. There are no assurances that the merger will be consummated on the currently expected timetable or at all. Unless stated otherwise, all forward-looking information contained in this report does not take into account or give any effect to the impact of the proposed merger. For the three and nine months ended September 30, 2015, UIL Holdings incurred pre-tax merger-related expenses of approximately $0.6 Further information concerning the proposed merger is included Note (C) “Regulatory Proceedings” and in a proxy statement/prospectus contained in a registration statement on Form S-4, as amended, filed by Iberdrola USA with the SEC on July 17, 2015 in connection with the proposed merger. Philadelphia Gas Works In March 2014, UIL Holdings entered into an Asset Purchase Agreement (the Asset Purchase Agreement) with the City of Philadelphia pursuant to which UIL Holdings, through a wholly-owned subsidiary, was to acquire the operating assets and assume certain liabilities of Philadelphia Gas Works. The proposed acquisition was subject to the satisfaction or waiver of certain customary and other closing conditions for transactions of this type, including approval from the Philadelphia City Council. In light of the City Council’s October 2014 announcement to not endorse the proposed acquisition, we exercised our contractual right to terminate the Asset Purchase Agreement in December 2014. For the three and nine month periods ended September 30, 2014, UIL Holdings incurred pre-tax acquisition-related expenses of approximately $1.4
Derivatives	Derivatives UIL Holdings’ regulated subsidiaries are parties to contracts, and involved in transactions, that are derivatives. Contracts for Differences (CfDs) Pursuant to Connecticut’s 2005 Energy Independence Act, PURA solicited bids to create new or incremental capacity resources in order to reduce federally mandated congestion charges, and selected four new capacity resources. To facilitate the transactions between the selected capacity resources and Connecticut electric customers, and provide the commitment necessary for owners of these resources to obtain necessary financing, PURA required that UI and The Connecticut Light and Power Company (CL&P) execute long-term contracts with the selected resources. In August 2007, PURA approved four CfDs, each of which specifies a capacity quantity and a monthly settlement that reflects the difference between a forward market price and the contract price. UI executed two of the contracts and CL&P executed the other two contracts. The costs or benefits of each contract will be paid by or allocated to customers and will be subject to a cost-sharing agreement between UI and CL&P pursuant to which approximately 20% of the cost or benefit is borne by or allocated to UI customers and approximately 80% is borne by or allocated to CL&P customers. PURA has determined that costs associated with these CfDs will be fully recoverable by UI and CL&P through electric rates, and in accordance with ASC 980 “Regulated Operations,” UI has deferred recognition of costs (a regulatory asset) or obligations (a regulatory liability). The CfDs are marked-to-market in accordance with ASC 815 “Derivatives and Hedging.” For those CfDs signed by CL&P, UI records its approximate 20% portion pursuant to the cost-sharing agreement noted above. As of September 30, 2015, UI has recorded a gross derivative asset of $31.5 million ($1.3 million of which is related to UI’s portion of the CfD signed by CL&P), a regulatory asset of $72.0 million, a gross derivative liability of $102.9 million ($65.1 million of which is related to UI’s portion of the CfD signed by CL&P) and a regulatory liability of $0.6 million. See Note (K) “Fair Value of Financial Instruments” for additional CfD information. The gross derivative assets and liabilities as of September 30, 2015 and December 31, 2014 were as follows: September 30, 2015 December 31, 2014 (In Thousands) Gross derivative assets: Current Assets $ 10,382 $ 6,849 Deferred Charges and Other Assets $ 21,134 $ 20,421 Gross derivative liabilities: Current Liabilities $ 28,206 $ 23,308 Noncurrent Liabilities $ 74,752 $ 61,766 The unrealized gains and losses from fair value adjustments to these derivatives, which are recorded in regulatory assets or regulatory liabilities, for the three- and nine-month periods ended September 30, 2015 and 2014 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands) (In Thousands) Regulatory Assets - Derivative liabilities $ (3,206 ) $ 393 $ 7,751 $ (81,623 ) Regulatory Liabilities - Derivative assets $ 313 $ 5,077 $ 5,886 $ (6,616 ) The fluctuations in the balances of the derivatives as well as the related unrealized gains in the three- and nine-month periods ended September 30, 2015 compared to the three- and nine-month periods ended September 30, 2014 are primarily due to fluctuations in forward prices for capacity and reserves. Weather Insurance Contracts On an annual basis, SCG and Berkshire each assess the need for weather insurance contracts for the upcoming heating season in order to provide financial protection from significant weather fluctuations. According to the terms of such contracts, if temperatures are warmer than normal at a prescribed level for the contract period, a payment is received by the gas company. The premiums paid are amortized over the terms of the contracts. The intrinsic value of the contracts is carried on the balance sheet with changes in value recorded in the income statement as Other Income and (Deductions). As a result of PURA’s approval of a decoupling mechanism for CNG which went into effect in January 2014, CNG does not enter into weather insurance contracts. In September 2015, SCG and Berkshire entered into weather insurance contracts for the winter period of November 1, 2015 through April 30, 2016. If temperatures are warmer than normal, SCG and Berkshire will receive payments up to a maximum of $3 million and $1 million, respectively.
Earnings per Share	Earnings per Share The following table presents a reconciliation of the basic and diluted earnings per share calculations for the three‑ and nine-month periods ended September 30, 2015 and 2014: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands, except per share amounts) Numerator: Net income attributable to UIL Holdings $ 15,626 $ 12,498 $ 89,067 $ 77,293 Less: Net income allocated to unvested units 7 7 44 45 Net income attributable to common shareholders $ 15,619 $ 12,491 $ 89,023 $ 77,248 Denominator: Basic average number of shares outstanding 57,150 56,855 57,120 56,827 Effect of dilutive securities (1) 288 278 300 287 Diluted average number of shares outstanding 57,438 57,133 57,420 57,114 Earnings per share: Basic $ 0.27 $ 0.22 $ 1.56 $ 1.36 Diluted $ 0.27 $ 0.22 $ 1.55 $ 1.35 (1) Includes unvested restricted stock and performance shares.
Equity and Other Investments	Equity and Other Investments UI is party to a 50-50 joint venture with the NRG affiliates in GenConn, which operates two peaking generation plants in Connecticut. UI’s investment in GenConn is being accounted for as an equity investment, the carrying value of which was $110.3 million and $114.2 million as of September 30, 2015 and December 31, 2014, respectively. As of September 30, 2015, there was $0.1 million of undistributed earnings from UI’s equity investment in GenConn. UI’s pre-tax income from its equity investment in GenConn was $3.4 million and $3.5 million for the September 30, 2015 and 2014, respectively. UI’s pre-tax income from its equity investment in GenConn for each of the nine-month periods ending September 30, 2015 and 2014 was $10.3 million and $10.4 million. Cash distributions from GenConn are reflected as either distributions of earnings or as returns of capital in the operating and investing sections of the Consolidated Statement of Cash Flows, respectively. UI received cash distributions from GenConn of $6.0 million and $5.5 million in the September 30, 2015 and 2014, respectively. UI received cash distributions from GenConn of $14.1 million and $14.3 million in the September 30, 2015, respectively and 2014. On July 24, 2015, UIL Holdings announced its participation in Tennessee Gas Pipeline Company LLC’s (TGP) proposed Northeast Energy Direct project (NED pipeline) through an acquisition of a 2.5% equity interest in Northeast Expansion LLC. Northeast Expansion LLC is a joint venture between an affiliate of Kinder Morgan, Inc., (Kinder Morgan) and Liberty Utilities (Pipeline & Transmission) Corp, which will construct and own the NED pipeline, a new, “market path” natural gas pipeline segment of approximately 188 miles from Wright, New York, to Dracut, Massachusetts. This 2.5% equity interest, which totaled approximately $1.6 million as of September 30, 2015, commits UIL Holdings to an initial capital investment opportunity that is expected to total up to approximately $80 million, depending on the final pipeline configuration and design capacity. Pursuant to an option agreement with Kinder Morgan, UIL Holdings also has the option to acquire up to an additional 12.5% of equity interests in Northeast Expansion LLC under certain limited circumstances, including if certain additional firm transportation agreements for service on the NED pipeline are entered into or if TGP does not sell additional volume on the NED pipeline. Any increase in equity ownership would increase UIL Holdings’ investment commitment proportionately. In addition, as a condition to making this investment, UIL Holdings entered into a 20-year Precedent Agreement with TGP for pipeline capacity of 70,000 Dekatherms/day on the NED pipeline, which capacity commitment, under the terms of the Precedent Agreement, would be reduced in the event that TGP enters into additional precedent agreements with third parties for capacity on the NED pipeline.
Regulatory Accounting	Regulatory Accounting Unless otherwise stated below, all of our regulatory assets earn a return. Our regulatory assets and liabilities as of September 30, 2015 and December 31, 2014 included the following: Remaining Period September 30, 2015 December 31, 2014 (In Thousands) Regulatory Assets: Unamortized redemption costs 7 to 19 years $ 9,897 $ 10,499 Pension and other post-retirement benefit plans (a) 395,356 402,700 Environmental remediation costs 7 years 14,461 13,197 Hardship programs (b) 19,625 24,744 Debt premium 2 to 23 years 23,694 27,498 Income taxes due principally to book-tax differences (c) 168,093 164,466 Unfunded future income taxes (d) 17,722 14,859 Contracts for differences (e) 72,027 64,276 Deferred transmission expense (f) 7,620 17,387 Other (g) 36,998 40,336 Total regulatory assets 765,493 779,962 Less current portion of regulatory assets 82,196 92,764 Regulatory Assets, Net $ 683,297 $ 687,198 Regulatory Liabilities: Accumulated deferred investment tax credits 29 years $ 7,245 $ 4,319 Excess generation service charge (h) 35,827 28,692 Middletown/Norwalk local transmission network service collections 35 years 20,398 20,828 Pension and other post-retirement benefit plans (a) 10,026 9,536 Asset retirement obligation (i) 7,061 7,248 Low income programs (j) 30,098 19,065 Asset removal costs (i) 357,099 336,028 Unfunded future income taxes (d) 25,991 26,318 Contracts for differences (e) 586 6,472 Deferred purchased gas (k) 638 4,736 Non-firm margin sharing credits 9 years 13,044 8,933 Other (g) 38,033 36,747 Total regulatory liabilities 546,046 508,922 Less current portion of regulatory liabilities 21,969 17,026 Regulatory Liabilities, Net $ 524,077 $ 491,896 (a) Life is dependent upon timing of final pension plan distribution; balance, which is fully offset by a corresponding asset/liability, is recalculated each year in accordance with ASC 715 "Compensation-Retirement Benefits." See Note (G) “Pension and Other Benefits” for additional information. (b) Hardship customer accounts deferred for future recovery to the extent they exceed the amount in rates. (c) Amortization period and/or balance vary depending on the nature and/or remaining life of the underlying assets/liabilities. (d) The balance will be extinguished when the asset, which is fully offset by a corresponding liability, or liability has been realized or settled, respectively. (e) Asset life is equal to delivery term of related contracts (which vary from approximately 5 - 12 years); balance fluctuates based upon quarterly market analysis performed on the related derivatives (Note K); amount, which does not earn a return, is fully offset by corresponding derivative asset/liability. See “-Contracts for Differences” discussion above for additional information. (f) Regulatory asset or liability which defers transmission income or expense and fluctuates based upon actual revenues and revenue requirements. (g) Amortization period and/or balance vary depending on the nature, cost of removal and/or remaining life of the underlying assets/liabilities; asset amount includes certain amounts that are not currently earning a return; September 30, 2015 liability amount includes decoupling of $18.9 million. (h) Regulatory asset or liability which defers generation-related and nonbypassable federally mandated congestion costs or revenues for future recovery from or return to customers. Amount fluctuates based upon timing differences between revenues collected from rates and actual costs incurred. (i) The liability will be extinguished simultaneous with the retirement of the assets and settlement of the corresponding asset retirement obligation. (j) Various hardship and payment plan programs approved for recovery. (k) Deferred purchased gas costs balances at the end of the rate year are normally recorded/returned in the next year.
Stock-Based Compensation	Stock-Based Compensation Pursuant to the UIL Holdings 2008 Stock and Incentive Compensation Plan (2008 Stock Plan), 94,410 restricted stock units were granted to certain members of management in March 2015; the average of the high and low market prices on the grant date, which approximate fair value, was $49.72 per share. Also in March 2015, we granted a total of 1,584 shares of restricted stock to our President and Chief Executive Officer under the 2008 Stock Plan and in accordance with his employment agreement; the average of the high and low market price on the date of grant, which approximates fair value, was $49.72 per share. Such shares vest in equal annual installments over a five-year period. In May 2015, UIL Holdings granted a total of 18,801 shares of restricted stock to non-employee directors under the 2008 Stock Plan; the average of the high and low market price on the date of grant, which approximates fair value, was $48.37 per share. Such shares vest in May 2016. Total stock-based compensation expense for the three-month periods ended September 30, 2015 and 2014 September 30, 2015 and 2014
Variable Interest Entities	Variable Interest Entities We have identified GenConn as a variable interest entity (VIE), which is accounted for under the equity method. UIL Holdings is not the primary beneficiary of GenConn, as defined in ASC 810 “Consolidation,” because it shares control of all significant activities of GenConn with its joint venturer, NRG affiliates. As such, GenConn is not subject to consolidation. GenConn recovers its costs through CfDs, which are cost of service-based and have been approved by PURA. As a result, with the achievement of commercial operation by GenConn Devon and GenConn Middletown, our exposure to loss is primarily related to the potential for unrecovered GenConn operating or future capital costs in a regulatory proceeding, the effect of which would be reflected in the carrying value of our 50% ownership position in GenConn and through “Income from Equity Investments” in UIL Holdings’ Consolidated Financial Statements. We have identified the selected capacity resources with which UI has CfDs as VIEs and have concluded that UI is not the primary beneficiary as UI does not have the power to direct any of the significant activities of these capacity resources. As such, we have not consolidated the selected capacity resources. UI’s maximum exposure to loss through these agreements is limited to the settlement amount under the CfDs as described in “–Derivatives – Contracts for Differences (CfDs)” above; however any such losses are fully recoverable through electric rates. UI has no requirement to absorb additional losses nor has UI provided any financial or other support during the periods presented that were not previously contractually required. We have identified the entities for which UI is required to enter into long-term contracts to purchase Renewable Energy Credits (RECs) as VIEs. In assessing these contracts for VIE identification and reporting purposes, we have aggregated the contracts based on similar risk characteristics and significance to UI. UI is not the primary beneficiary as UI does not have the power to direct any of the significant activities of these entities. UI’s exposure to loss is primarily related to the purchase and resale of the RECs, but, any losses incurred are recoverable through electric rates. For further discussion of RECs, see Note (C) “Regulatory Proceedings – Electric Distribution and Transmission – New Renewable Source Generation.”
New Accounting Pronouncements	New Accounting Pronouncements In August 2015, the FASB issued Accounting Standards Update (ASU) 2015-13, “Derivatives and Hedging” which specifies that the use of locational marginal pricing by an independent system operator does not constitute net settlement of a forward contract for the purchase or sale of electricity and does not cause that contract to fail to meet the physical delivery criterion of the normal purchases and normal sales scope exception. This guidance was effective upon issuance and does have an impact on UIL Holdings’ consolidated financial statements. In August 2015, the FASB issued Accounting Standards Update (ASU) 2015-14, “Revenue from Contracts with Customers” which defers the effective date of ASU 2014-09 by one year. ASU 2014-09 requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. We are currently evaluating the effect that adopting this new accounting guidance will have on our consolidated financial statements. Also in August 2015, the FASB issued Accounting Standards Update (ASU) 2015-15, “Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements” which incorporates SEC guidance into ASC 835 “Interest” that allows an entity to defer and present debt issuance costs related to line of credit arrangements as an asset and subsequently amortize such costs ratably over the term of the arrangement regardless of whether there are any outstanding borrowings on the line of credit. This guidance is not expected to be material to UIL Holdings’ consolidated financial statements. In July 2015, the FASB issued Accounting Standards Update (ASU) 2015-11, “Inventory – Simplifying the Measurement of Inventory” which requires inventory that is measured using first-in, first-out or average cost methods to be measured using the lower of cost and net realizable value. ASU 2015-11 is effective for interim and annual reporting periods beginning after December 15, 2016 and is to be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. This is not expected to be material to UIL Holdings’ consolidated financial statements. In April 2015, the FASB issued Accounting Standards Update (ASU) 2015-03, “Interest—Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs” which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is effective for interim and annual reporting periods beginning after December 15, 2015 and is to be applied retrospectively. Adopting this new accounting guidance will reduce both Deferred Charges and Other Assets and Long-term debt on the consolidated balance sheet. This effect is not expected to be material to UIL Holdings’ consolidated financial statements.

BUSINESS ORGANIZATION AND STA19

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2015
BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES [Abstract]
Value of Gross Derivative Assets and Liabilities	The gross derivative assets and liabilities as of September 30, 2015 and December 31, 2014 were as follows: September 30, 2015 December 31, 2014 (In Thousands) Gross derivative assets: Current Assets $ 10,382 $ 6,849 Deferred Charges and Other Assets $ 21,134 $ 20,421 Gross derivative liabilities: Current Liabilities $ 28,206 $ 23,308 Noncurrent Liabilities $ 74,752 $ 61,766
Unrealized Gains and Losses From Mark-To-Market Adjustments	The unrealized gains and losses from fair value adjustments to these derivatives, which are recorded in regulatory assets or regulatory liabilities, for the three- and nine-month periods ended September 30, 2015 and 2014 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands) (In Thousands) Regulatory Assets - Derivative liabilities $ (3,206 ) $ 393 $ 7,751 $ (81,623 ) Regulatory Liabilities - Derivative assets $ 313 $ 5,077 $ 5,886 $ (6,616 )
Reconciliation of Basic and Diluted Earnings Per Share	The following table presents a reconciliation of the basic and diluted earnings per share calculations for the three‑ and nine-month periods ended September 30, 2015 and 2014: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands, except per share amounts) Numerator: Net income attributable to UIL Holdings $ 15,626 $ 12,498 $ 89,067 $ 77,293 Less: Net income allocated to unvested units 7 7 44 45 Net income attributable to common shareholders $ 15,619 $ 12,491 $ 89,023 $ 77,248 Denominator: Basic average number of shares outstanding 57,150 56,855 57,120 56,827 Effect of dilutive securities (1) 288 278 300 287 Diluted average number of shares outstanding 57,438 57,133 57,420 57,114 Earnings per share: Basic $ 0.27 $ 0.22 $ 1.56 $ 1.36 Diluted $ 0.27 $ 0.22 $ 1.55 $ 1.35 (1) Includes unvested restricted stock and performance shares.
Regulatory Assets and Liabilities	Unless otherwise stated below, all of our regulatory assets earn a return. Our regulatory assets and liabilities as of September 30, 2015 and December 31, 2014 included the following: Remaining Period September 30, 2015 December 31, 2014 (In Thousands) Regulatory Assets: Unamortized redemption costs 7 to 19 years $ 9,897 $ 10,499 Pension and other post-retirement benefit plans (a) 395,356 402,700 Environmental remediation costs 7 years 14,461 13,197 Hardship programs (b) 19,625 24,744 Debt premium 2 to 23 years 23,694 27,498 Income taxes due principally to book-tax differences (c) 168,093 164,466 Unfunded future income taxes (d) 17,722 14,859 Contracts for differences (e) 72,027 64,276 Deferred transmission expense (f) 7,620 17,387 Other (g) 36,998 40,336 Total regulatory assets 765,493 779,962 Less current portion of regulatory assets 82,196 92,764 Regulatory Assets, Net $ 683,297 $ 687,198 Regulatory Liabilities: Accumulated deferred investment tax credits 29 years $ 7,245 $ 4,319 Excess generation service charge (h) 35,827 28,692 Middletown/Norwalk local transmission network service collections 35 years 20,398 20,828 Pension and other post-retirement benefit plans (a) 10,026 9,536 Asset retirement obligation (i) 7,061 7,248 Low income programs (j) 30,098 19,065 Asset removal costs (i) 357,099 336,028 Unfunded future income taxes (d) 25,991 26,318 Contracts for differences (e) 586 6,472 Deferred purchased gas (k) 638 4,736 Non-firm margin sharing credits 9 years 13,044 8,933 Other (g) 38,033 36,747 Total regulatory liabilities 546,046 508,922 Less current portion of regulatory liabilities 21,969 17,026 Regulatory Liabilities, Net $ 524,077 $ 491,896 (a) Life is dependent upon timing of final pension plan distribution; balance, which is fully offset by a corresponding asset/liability, is recalculated each year in accordance with ASC 715 "Compensation-Retirement Benefits." See Note (G) “Pension and Other Benefits” for additional information. (b) Hardship customer accounts deferred for future recovery to the extent they exceed the amount in rates. (c) Amortization period and/or balance vary depending on the nature and/or remaining life of the underlying assets/liabilities. (d) The balance will be extinguished when the asset, which is fully offset by a corresponding liability, or liability has been realized or settled, respectively. (e) Asset life is equal to delivery term of related contracts (which vary from approximately 5 - 12 years); balance fluctuates based upon quarterly market analysis performed on the related derivatives (Note K); amount, which does not earn a return, is fully offset by corresponding derivative asset/liability. See “-Contracts for Differences” discussion above for additional information. (f) Regulatory asset or liability which defers transmission income or expense and fluctuates based upon actual revenues and revenue requirements. (g) Amortization period and/or balance vary depending on the nature, cost of removal and/or remaining life of the underlying assets/liabilities; asset amount includes certain amounts that are not currently earning a return; September 30, 2015 liability amount includes decoupling of $18.9 million. (h) Regulatory asset or liability which defers generation-related and nonbypassable federally mandated congestion costs or revenues for future recovery from or return to customers. Amount fluctuates based upon timing differences between revenues collected from rates and actual costs incurred. (i) The liability will be extinguished simultaneous with the retirement of the assets and settlement of the corresponding asset retirement obligation. (j) Various hardship and payment plan programs approved for recovery. (k) Deferred purchased gas costs balances at the end of the rate year are normally recorded/returned in the next year.

SUPPLEMENTARY INFORMATION (Tabl

SUPPLEMENTARY INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2015
SUPPLEMENTARY INFORMATION [Abstract]
Supplementary Information	Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In Thousands) (In Thousands) Depreciation and Amortization Property, plant, and equipment depreciation $ 37,081 $ 32,860 $ 106,185 $ 97,208 Amortization of regulatory assets 3,534 2,718 17,094 15,200 Total Depreciation and Amortization $ 40,615 $ 35,578 $ 123,279 $ 112,408 Taxes - Other than Income Taxes Operating: Connecticut gross earnings $ 18,180 $ 16,199 $ 56,353 $ 54,671 Local real estate and personal property 14,085 13,310 40,080 37,399 Payroll taxes 2,886 3,046 11,064 9,877 Other 45 342 848 1,027 Total Taxes - Other than Income Taxes $ 35,196 $ 32,897 $ 108,345 $ 102,974 Other Income and (Deductions) Interest income $ 77 $ 666 $ 1,458 $ 1,731 Allowance for funds used during construction - equity 2,589 1,949 6,698 6,869 Allowance for funds used during construction - debt 1,292 1,201 3,424 4,032 Weather insurance - - - (2,437 ) Other 263 520 1,303 2,627 Total Other Income and (Deductions) $ 4,221 $ 4,336 $ 12,883 $ 12,822

PENSION AND OTHER BENEFITS (Tab

PENSION AND OTHER BENEFITS (Tables)	9 Months Ended
	Sep. 30, 2015
PENSION AND OTHER BENEFITS [Abstract]
Components of Net Periodic Benefit Cost for Pension and Other Postretirement Benefits	The following tables represent the components of net periodic benefit cost for pension and other postretirement benefits as well as the actuarial weighted-average assumptions used in calculating net periodic benefit cost for the three-and nine‑month periods ended : Three Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 (In Thousands) Components of net periodic benefit cost: Service cost $ 3,605 $ 2,896 $ 393 $ 404 Interest cost 10,505 11,019 1,327 1,487 Expected return on plan assets (14,120 ) (13,560 ) (690 ) (700 ) Amortization of prior service costs 48 73 75 71 Amortization of actuarial (gain) loss 4,845 3,097 176 (172 ) Net periodic benefit cost $ 4,883 $ 3,525 $ 1,281 $ 1,090 Nine Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 (In Thousands) Components of net periodic benefit cost: Service cost $ 10,815 $ 8,688 $ 1,179 $ 1,212 Interest cost 31,515 33,057 3,981 4,461 Expected return on plan assets (42,360 ) (40,680 ) (2,070 ) (2,100 ) Amortization of prior service costs 144 219 225 213 Amortization of actuarial (gain) loss 14,535 9,291 528 (516 ) Net periodic benefit cost $ 14,649 $ 10,575 $ 3,843 $ 3,270
Weighted Average Actuarial Assumption used in Calculating Net Periodic Benefit Cost	The following tables represent the components of net periodic benefit cost for pension and other postretirement benefits as well as the actuarial weighted-average assumptions used in calculating net periodic benefit cost for the three-and nine‑month periods ended : Three and Nine Months Ended September 30, Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.20%-4.30 % 4.90%-5.20 % 4.20%-4.30 % 4.85%-5.20 % Average wage increase 3.50%-3.80 % 3.50%-3.80 % N/A N/A Return on plan assets 7.75%-8.00 % 7.75%-8.00 % 5.56%-8.00 % 5.56%-8.00 % Composite health care trend rate (current year) N/A N/A 7.00 % 7.00 % Composite health care trend rate (2019 forward) N/A N/A 5.00 % 5.00 % N/A – not applicable

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2015
FAIR VALUE MEASUREMENTS [Abstract]
Fair Value of Financial Assets and Liabilities	The following tables set forth the fair value of our financial assets and liabilities, other than pension benefits and other postretirement benefits, as of September 30, 2015 and December 31, 2014. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2015 (In Thousands) Assets: Derivative assets $ - $ - 31,516 $ 31,516 Noncurrent investments 13,141 - - 13,141 Deferred Compensation Plan 3,529 - - 3,529 Supplemental retirement benefit trust life insurance policies - 8,254 - 8,254 $ 16,670 $ 8,254 $ 31,516 $ 56,440 Liabilities: Derivative liabilities $ - $ - $ 102,958 $ 102,958 Long-term debt - 1,908,931 - 1,908,931 $ - $ 1,908,931 $ 102,958 $ 2,011,889 Net fair value assets/(liabilities), September 30, 2015 $ 16,670 $ (1,900,677 ) $ (71,442 ) $ (1,955,449 ) December 31, 2014 Assets: Derivative assets $ - $ - $ 27,270 $ 27,270 Noncurrent investments 11,387 - - 11,387 Deferred Compensation Plan 3,624 - - 3,624 Supplemental retirement benefit trust life insurance policies - 8,498 - 8,498 $ 15,011 $ 8,498 $ 27,270 $ 50,779 Liabilities: Derivative liabilities $ - $ - $ 85,074 $ 85,074 Long-term debt - 1,941,711 - 1,941,711 $ - $ 1,941,711 $ 85,074 $ 2,026,785 Net fair value assets/(liabilities), December 31, 2014 $ 15,011 $ (1,933,213 ) $ (57,804 ) $ (1,976,006 )
Additional Quantitative Information about Level 3 Fair Value Measurements	Additional quantitative information about Level 3 fair value measurements is as follows: Unobservable Input Range at Range at Contracts for differences Risk of non-performance 0.31% - 0.94 % 0.00% - 0.66 % Discount rate 1.37% - 2.06 % 1.65% - 2.25 % Forward pricing ($ per MW) $ 3.15 - $11.19 $ 3.15 - $14.59
Changes in Fair Value of Assets and Liabilities Classified as level 3	The following tables set forth a reconciliation of changes in the fair value of the assets and liabilities above that are classified as Level 3 in the fair value hierarchy for the nine-month period ended September 30, 2015. Nine Months Ended (In Thousands) Net derivative assets/(liabilities), December 31, 2014 $ (57,804 ) Unrealized gains and (losses), net (13,638 ) Net derivative assets/(liabilities), September 30, 2015 $ (71,442 ) Change in unrealized gains (losses), net relating to net derivative assets/(liabilities), still held as of September 30, 2015 $ (13,638 )
Change in Regulatory Asset/(Liability) Balance	The following table sets forth a reconciliation of changes in the net regulatory asset/ (liability) balances that were established to recover any unrealized gains/(losses) associated with the CfDs for the nine-month period ended September 30, 2015. The amounts offset the net CfDs liabilities included in the derivative liabilities detailed above. Nine Months Ended (In Thousands) Net regulatory assets/(liabilities), December 31, 2014 $ 57,804 Unrealized (gains) and losses, net 13,638 Net regulatory assets/(liabilities), September 30, 2015 $ 71,442

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2015
SEGMENT INFORMATION [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated Financial Statements	UIL Holdings is organized into Electric Distribution, Electric Transmission and Gas Distribution reporting segments based on several factors including, but not limited to, the nature of each segment’s products and services, the sources of operating revenues and expenses and the regulatory environment in which each segment operates. The following measures of segment profit and loss are utilized by management to make decisions about allocating resources to the segments and assessing performance. The following table reconciles certain segment information with that provided in our Consolidated Financial Statements. In the table, distribution includes all electric utility revenue and expenses except for transmission, which is provided in a separate column. “Other” includes the information for the remainder of our non‑utility activities and unallocated corporate costs, including minority interest investments and administrative costs. Revenues from inter‑segment transactions are not material. All of our revenues are derived in the United States. (In Thousands) Three months ended September 30, 2015 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 158,587 $ 77,767 $ 236,354 $ 94,170 $ - $ 330,524 Purchased power and gas 47,041 - 47,041 27,715 (1,402 ) 73,354 Operation and maintenance 55,394 14,838 70,232 47,805 (6,751 ) 111,286 Transmission wholesale - 30,272 30,272 - - 30,272 Depreciation and amortization 13,554 4,475 18,029 17,285 5,301 40,615 Taxes - other than income taxes 14,721 11,680 26,401 8,509 286 35,196 Merger and acquisition-related expenses - - - - 600 600 Operating Income 27,877 16,502 44,379 (7,144 ) 1,966 39,201 Other Income and (Deductions), net 1,682 375 2,057 1,594 570 4,221 Interest Charges, net 8,789 3,086 11,875 6,723 5,789 24,387 Income from Equity Investments 3,408 - 3,408 - - 3,408 Income (Loss) Before Income Taxes 24,178 13,791 37,969 (12,273 ) (3,253 ) 22,443 Income Taxes 6,032 5,374 11,406 (4,862 ) 267 6,811 Net Income (Loss) 18,146 8,417 26,563 (7,411 ) (3,520 ) 15,632 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 6 - 6 Net Income (Loss) attributable to UIL Holdings $ 18,146 $ 8,417 $ 26,563 $ (7,417 ) $ (3,520 ) $ 15,626 Total Capital Expenditures (1) $ - $ - $ 41,466 $ 39,744 $ 13,818 $ 95,028 Three months ended September 30, 2014 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 134,289 $ 62,926 $ 197,215 $ 94,708 $ 1,103 $ 293,026 Purchased power and gas 37,962 - 37,962 30,504 310 68,776 Operation and maintenance 42,819 11,456 54,275 44,950 (3,974 ) 95,251 Transmission wholesale - 25,802 25,802 - - 25,802 Depreciation and amortization 11,943 4,208 16,151 16,477 2,950 35,578 Taxes - other than income taxes 14,244 10,441 24,685 9,082 (870 ) 32,897 Merger and Acquisition-related expenses - - - - 570 570 Operating Income 27,321 11,019 38,340 (6,305 ) 2,117 34,152 Other Income and (Deductions), net 2,877 881 3,758 702 (973 ) 3,487 Interest Charges, net 7,590 3,375 10,965 7,116 5,560 23,641 Income from Equity Investments 3,492 - 3,492 - - 3,492 Income (Loss) Before Income Taxes 26,100 8,525 34,625 (12,719 ) (4,416 ) 17,490 Income Taxes 8,173 3,048 11,221 (6,229 ) (6 ) 4,986 Net Income (Loss) 17,927 5,477 23,404 (6,490 ) (4,410 ) 12,504 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 6 - 6 Net Income (Loss) attributable to UIL Holdings $ 17,927 $ 5,477 $ 23,404 $ (6,496 ) $ (4,410 ) $ 12,498 Total Capital Expenditures (1) $ - $ - $ 31,523 $ 32,926 $ 6,181 $ 70,630 (In Thousands) Nine months ended September 30, 2015 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 481,278 $ 195,481 $ 676,759 $ 549,825 $ - $ 1,226,584 Purchased power and gas 180,858 - 180,858 244,732 (3,798 ) 421,792 Operation and maintenance 152,747 42,415 195,162 137,590 (17,115 ) 315,637 Transmission wholesale - 67,969 67,969 - - 67,969 Depreciation and amortization 40,678 13,036 53,714 57,545 12,020 123,279 Taxes - other than income taxes 42,963 28,216 71,179 36,271 895 108,345 Merger and acquisition-related expenses - - - - 7,395 7,395 Operating Income 64,032 43,845 107,877 73,687 603 182,167 Other Income and (Deductions), net 5,591 2,925 8,516 2,617 1,750 12,883 Interest Charges, net 24,979 9,852 34,831 20,405 17,445 72,681 Income from Equity Investments 10,284 - 10,284 - - 10,284 Income (Loss) Before Income Taxes 54,928 36,918 91,846 55,899 (15,092 ) 132,653 Income Taxes 14,980 14,228 29,208 20,651 (6,293 ) 43,566 Net Income (Loss) 39,948 22,690 62,638 35,248 (8,799 ) 89,087 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - 20 - 20 Net Income (Loss) attributable to UIL Holdings $ 39,948 $ 22,690 $ 62,638 $ 35,228 $ (8,799 ) $ 89,067 Total Capital Expenditures (1) $ - $ - $ 119,677 $ 93,094 $ 41,426 $ 254,197 Nine months ended September 30, 2014 Electric Distribution and Transmission Distribution Transmission Total Gas Distribution Other Total Operating Revenues $ 397,384 $ 183,715 $ 581,099 $ 616,780 $ 1,103 $ 1,198,982 Purchased power and gas 123,771 - 123,771 321,986 310 446,067 Operation and maintenance 135,282 36,049 171,331 130,761 (11,264 ) 290,828 Transmission wholesale - 65,777 65,777 - - 65,777 Depreciation and amortization 35,902 12,635 48,537 55,994 7,877 112,408 Taxes - other than income taxes 38,597 26,832 65,429 37,080 465 102,974 Merger and acquisition-related expenses - - - - 6,090 6,090 Operating Income 63,832 42,422 106,254 70,959 (2,375 ) 174,838 Other Income and (Deductions), net 9,503 2,793 12,296 (587 ) (14,075 ) (2,366 ) Interest Charges, net 22,661 9,832 32,493 21,320 16,509 70,322 Income from Equity Investments 10,398 - 10,398 - - 10,398 Income (Loss) Before Income Taxes 61,072 35,383 96,455 49,052 (32,959 ) 112,548 Income Taxes 18,015 12,262 30,277 18,749 (13,750 ) 35,276 Net Income (Loss) 43,057 23,121 66,178 30,303 (19,209 ) 77,272 Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests - - - (21 ) - (21 ) Net Income (Loss) attributable to UIL Holdings $ 43,057 $ 23,121 $ 66,178 $ 30,324 $ (19,209 ) $ 77,293 Total Capital Expenditures (1) $ - $ - $ 91,600 $ 78,278 $ 26,293 $ 196,171
Reconciliation of Total Assets from Segments to Consolidated Financial Statements	Electric Distribution and Transmission (2) Distribution Transmission Total Gas Distribution (3) Other Total (3) Total Assets at September 30, 2015 $ - $ - $ 2,930,013 $ 2,069,913 $ 172,440 $ 5,172,366 Total Assets at December 31, 2014 $ - $ - $ 2,876,792 $ 2,087,284 $ 147,859 $ 5,111,935 (1) Information for segmenting total capital expenditures between Distribution and Transmission is not available. Total Electric Distribution and Transmission capital expenditures are disclosed in the Total Electric Distribution and Transmission column. (2) Information for segmenting total assets between Distribution and Transmission is not available. Total Electric Distribution and Transmission assets are disclosed in the Total Electric and Distribution and Transmission column. Net plant in service is segregated by segment and, as of September 30, 2015, was $1,343.4 million and $699.7 million for Distribution and Transmission, respectively. As of December 31, 2014, net plant in service was $1,283.6 million and $659.4 million for Distribution and Transmission, respectively. (3) Includes $266.2 million of goodwill in the Gas Distribution segment as of September 30, 2015 and December 31, 2014.

BUSINESS ORGANIZATION AND STA24

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES (Details)	Sep. 30, 2015
Ownership percentage in GenConn [Abstract]
Ownership percentage in joint venture	50.00%

BUSINESS ORGANIZATION AND STA25

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Proposed Merger with Iberddrola USA and Philadelphia Gas Works (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Feb. 25, 2015
Business Acquisition [Line Items]
Merger and acquisition-related expenses	$ 600	$ 570	$ 7,395	$ 6,090
Acquisition-related bridge facility fees	0	(849)	0	(15,188)
Philadelphia Gas Works [Member] | Bridge Facility [Member]
Business Acquisition [Line Items]
Merger and acquisition-related expenses		600		6,100
Pre-tax acquisition-related expenses		1,400		21,300
Acquisition-related bridge facility fees		$ 800		$ 15,200
Iberdrola USA [Member]
Business Acquisition [Line Items]
Cash consideration per share (in dollars per share)					$ 10.5
Percentage of ownership arise from merger					18.50%
Merger and acquisition-related expenses	$ 600		$ 7,400

BUSINESS ORGANIZATION AND STA26

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Derivatives (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)CapacityResourceCapacityResources	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)CapacityResourceCapacityResources	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Derivatives [Abstract]
Number of new capacity resources selected | CapacityResource	4		4
Number of Contracts for Differences (CfDs) | CapacityResources	4		4
Weather insurance	$ 0	$ 0	$ 0	$ (2,437)
Gross derivative assets [Abstract]
Gross derivative asset	31,500		31,500
Regulatory asset	72,000		72,000
Current Assets	10,382		10,382		$ 6,849
Deferred Charges and Other Assets	21,134		21,134		20,421
Gross derivative liabilities [Abstract]
Gross derivative liability	102,900		102,900
Regulatory liabilities	600		600
Current Liabilities	28,206		28,206		23,308
Noncurrent Liabilities	74,752		74,752		$ 61,766
Unrealized gain and losses from mark-to-market adjustments [Abstract]
Regulatory Assets - Derivative liability	(3,206)	393	7,751	(81,623)
Regulatory Liabilities - Derivative assets	$ 313	$ 5,077	$ 5,886	$ (6,616)
United Illuminating Company (UI) [Member]
Derivatives [Abstract]
Number of Contracts for Differences (CfDs) | CapacityResources	2		2
Percentage of contract costs or benefits assumed by customers	20.00%
Gross derivative assets [Abstract]
Gross derivative asset	$ 1,300		$ 1,300
Gross derivative liabilities [Abstract]
Gross derivative liability	$ 65,100		$ 65,100
Connecticut Light and Power [Member]
Derivatives [Abstract]
Number of Contracts for Differences (CfDs) | CapacityResources	2		2
Percentage of contract costs or benefits assumed by customers	80.00%
SCG [Member]
Derivatives [Abstract]
Weather insurance			$ 3,000
Berkshire [Member]
Derivatives [Abstract]
Weather insurance			$ 1,000

BUSINESS ORGANIZATION AND STA27

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator [Abstract]
Net income attributable to UIL Holdings		$ 15,626	$ 12,498	$ 89,067	$ 77,293
Less: Net income allocated to unvested units		7	7	44	45
Net income attributable to common shareholders		$ 15,619	$ 12,491	$ 89,023	$ 77,248
Denominator [Abstract]
Basic average number of shares outstanding (in shares)		57,150	56,855	57,120	56,827
Effect of dilutive securities (in shares)	[1]	288	278	300	287
Diluted average number of shares outstanding (in shares)		57,438	57,133	57,420	57,114
Earnings per share [Abstract]
Basic (in dollars per share)		$ 0.27	$ 0.22	$ 1.56	$ 1.36
Diluted (in dollars per share)		$ 0.27	$ 0.22	$ 1.55	$ 1.35
[1]	Includes unvested restricted stock and performance shares.

BUSINESS ORGANIZATION AND STA28

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Equity Investments (Details) $ in Thousands	Jul. 24, 2015USD ($)Dekathermsdaymi	Sep. 30, 2015USD ($)Plant	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)Plant	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Equity Investments [Abstract]
Carrying value of joint venture		$ 110,346		$ 110,346		$ 114,195
Income (loss) from equity investment		$ 3,408	$ 3,492	$ 10,284	$ 10,398
GenConn [Member]
Equity Investments [Abstract]
Number of peaking generation plants | Plant		2		2
Carrying value of joint venture		$ 110,300		$ 110,300		$ 114,200
Undistributed earnings in equity method investment		100		100
Income (loss) from equity investment		3,400	3,500	10,300	10,400
Distributions received from joint venture		6,000	$ 5,500	14,100	$ 14,300
Northeast Expansion LLC [Member]
Equity Investments [Abstract]
Carrying value of joint venture		$ 1,600		$ 1,600
Miles of natural gas pipeline segment | mi	188
Equity interest	2.50%
Initial capital investment	$ 80,000
Additional optional equity interest	12.50%
Agreement period	20 years
Pipeline capacity (dekatherms per day) | Dekathermsday	70,000

BUSINESS ORGANIZATION AND STA29

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Regulatory Assets (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015	Dec. 31, 2014
Regulatory Assets [Line Items]
Total Regulatory Assets		$ 765,493	$ 779,962
Less current portion of regulatory assets		82,196	92,764
Regulatory Assets, Net		683,297	687,198
Unamortized Redemption Costs [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets		$ 9,897	10,499
Unamortized Redemption Costs [Member] | Minimum [Member]
Regulatory Assets [Line Items]
Remaining period		7 years
Unamortized Redemption Costs [Member] | Maximum [Member]
Regulatory Assets [Line Items]
Remaining period		19 years
Pension and Other Post-Retirement Benefit Plans [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[1]	$ 395,356	402,700
Environmental Remediation Costs [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets		$ 14,461	13,197
Remaining period		7 years
Hardship Programs [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[2]	$ 19,625	24,744
Debt Premium [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets		$ 23,694	27,498
Debt Premium [Member] | Minimum [Member]
Regulatory Assets [Line Items]
Remaining period		2 years
Debt Premium [Member] | Maximum [Member]
Regulatory Assets [Line Items]
Remaining period		23 years
Income Taxes Due Principally to Book Tax Differences [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[3]	$ 168,093	164,466
Unfunded Future Income Taxes [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[4]	17,722	14,859
Contracts For Differences [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[5]	$ 72,027	64,276
Contracts For Differences [Member] | Minimum [Member]
Regulatory Assets [Line Items]
Term of contracts		5 years
Contracts For Differences [Member] | Maximum [Member]
Regulatory Assets [Line Items]
Term of contracts		12 years
Deferred Transmission Expense [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[6]	$ 7,620	17,387
Other [Member]
Regulatory Assets [Line Items]
Total Regulatory Assets	[7]	$ 36,998	$ 40,336
[1]	Life is dependent upon timing of final pension plan distribution; balance, which is fully offset by a corresponding asset/liability, is recalculated each year in accordance with ASC 715 "Compensation-Retirement Benefits." See Note (G) "Pension and Other Benefits" for additional information.
[2]	Hardship customer accounts deferred for future recovery to the extent they exceed the amount in rates.
[3]	Amortization period and/or balance vary depending on the nature and/or remaining life of the underlying assets/liabilities.
[4]	The balance will be extinguished when the asset, which is fully offset by a corresponding liability, or liability has been realized or settled, respectively.
[5]	Asset life is equal to delivery term of related contracts (which vary from approximately 5 - 12 years); balance fluctuates based upon quarterly market analysis performed on the related derivatives (Note K); amount, which does not earn a return, is fully offset by corresponding derivative asset/liability. See "-Contracts for Differences" discussion above for additional information.
[6]	Regulatory asset or liability which defers transmission income or expense and fluctuates based upon actual revenues and revenue requirements.
[7]	Amortization period and/or balance vary depending on the nature, cost of removal and/or remaining life of the underlying assets/liabilities; asset amount includes certain amounts that are not currently earning a return; September 30, 2015 liability amount includes decoupling of $18.9 million.

BUSINESS ORGANIZATION AND STA30

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Regulatory Liabilities (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015	Dec. 31, 2014
Regulatory Liabilities [Line Items]
Total regulatory liabilities		$ 546,046	$ 508,922
Less current portion of regulatory liabilities		21,969	17,026
Regulatory Liabilities, Net		524,077	491,896
Accumulated Deferred Investment Tax Credits [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities		$ 7,245	4,319
Remaining period		29 years
Excess Generation Service Charge [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[1]	$ 35,827	28,692
Middletown/Norwalk Local Transmission Network Service Collections [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities		$ 20,398	20,828
Remaining period		35 years
Pension and Other Post-Retirement Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[2]	$ 10,026	9,536
Asset Retirement Obligation [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[3]	7,061	7,248
Low Income Programs [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[4]	30,098	19,065
Asset Removal Costs [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[3]	357,099	336,028
Unfunded Future Income Taxes [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[5]	25,991	26,318
Contracts For Differences [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[6]	586	6,472
Deferred Purchased Gas [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[7]	638	4,736
Non-Firm Margin Sharing Credits [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities		$ 13,044	8,933
Remaining period		9 years
Other [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	[8]	$ 38,033	$ 36,747
Decoupling Liability [Member]
Regulatory Liabilities [Line Items]
Liability decoupling amount		$ 18,900
[1]	Regulatory asset or liability which defers generation-related and nonbypassable federally mandated congestion costs or revenues for future recovery from or return to customers. Amount fluctuates based upon timing differences between revenues collected from rates and actual costs incurred.
[2]	Life is dependent upon timing of final pension plan distribution; balance, which is fully offset by a corresponding asset/liability, is recalculated each year in accordance with ASC 715 "Compensation-Retirement Benefits." See Note (G) "Pension and Other Benefits" for additional information.
[3]	The liability will be extinguished simultaneous with the retirement of the assets and settlement of the corresponding asset retirement obligation.
[4]	Various hardship and payment plan programs approved for recovery.
[5]	The balance will be extinguished when the asset, which is fully offset by a corresponding liability, or liability has been realized or settled, respectively.
[6]	Asset life is equal to delivery term of related contracts (which vary from approximately 5 - 12 years); balance fluctuates based upon quarterly market analysis performed on the related derivatives (Note K); amount, which does not earn a return, is fully offset by corresponding derivative asset/liability. See "-Contracts for Differences" discussion above for additional information.
[7]	Deferred purchased gas costs balances at the end of the rate year are normally recorded/returned in the next year.
[8]	Amortization period and/or balance vary depending on the nature, cost of removal and/or remaining life of the underlying assets/liabilities; asset amount includes certain amounts that are not currently earning a return; September 30, 2015 liability amount includes decoupling of $18.9 million.

BUSINESS ORGANIZATION AND STA31

BUSINESS ORGANIZATION AND STATEMENT OF ACCOUNTING POLICIES, Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	May. 31, 2015	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense			$ 0.7	$ 6.1	$ 3.4
Management [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)		94,410
Weighted average grant date fair value (in dollars per share)		$ 49.72
President and Chief Executive Officer [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)		1,584
Weighted average grant date fair value (in dollars per share)		$ 49.72
Vesting period		5 years
Non-Employee Directors [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)	18,801
Weighted average grant date fair value (in dollars per share)	$ 48.37

CAPITALIZATION (Details)

CAPITALIZATION (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 29, 2015	Sep. 30, 2015
Series G Senior Notes Due in 2045 [Member]
Capitalization [Abstract]
Long term debt interest percentage	4.61%
Long-term debt payable	$ 50
Repayment of pollution control refunding revenue bonds	$ 27.5
Common Stock [Member]
Capitalization [Abstract]
Common stock outstanding (in shares)		56,629,377
Common stock par value (in dollars per share)		$ 0

REGULATORY PROCEEDINGS, Propose

REGULATORY PROCEEDINGS, Proposed Merger With Iberdrola USA (Details) $ in Millions	Sep. 18, 2015USD ($)	Sep. 16, 2015USD ($)	Jul. 31, 2015USD ($)UtilitiesEmployee	Oct. 19, 2015USD ($)
Iberdrola USA [Member]
Proposed Merger with Iberdrola USA [Abstract]
Rate credits to customers			$ 20
Clean energy fund and disaster relief contributions			7
Delayed capital recovery			$ 7
Connecticut Utilities | Utilities			3
Employees or contractors | Employee			150
Number of years over which to hire employees or contractors			3 years
Number of years over which to improve metrics			3 years
Estimated remediation costs		$ 30
Connecticut Natural Gas Corporation (CNG) [Member]
Proposed Merger with Iberdrola USA [Abstract]
Rate credits to customers	$ 12.5
Allocation period for rate credits to customers	10 years
The Southern Connecticut Gas Company (SCG) [Member]
Proposed Merger with Iberdrola USA [Abstract]
Rate credits to customers	$ 7.5
Allocation period for rate credits to customers	10 years
The Berkshire Gas Company [Member]
Proposed Merger with Iberdrola USA [Abstract]
Rate credits to customers				$ 4
DPU Settlement Agreement Commitment				$ 1

REGULATORY PROCEEDINGS, Rates (

REGULATORY PROCEEDINGS, Rates (Details)	Jan. 22, 2014	Sep. 30, 2015
Connecticut Natural Gas Corporation (CNG) [Member]
Distribution Rates [Abstract]
Return on equity, approved	9.18%	9.18%
The Southern Connecticut Gas Company (SCG) [Member]
Distribution Rates [Abstract]
Return on equity, approved		9.36%
The Berkshire Gas Company [Member]
Distribution Rates [Abstract]
Return on equity, approved		10.50%
United Illuminating Company (UI) [Member]
Distribution Rates [Abstract]
Return on equity, approved		9.15%
Profit sharing percentage		50.00%

REGULATORY PROCEEDINGS, Power S

REGULATORY PROCEEDINGS, Power Supply Arrangements (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)Rating
Power Supply Arrangements [Abstract]
Percentage of standard service customers with wholesale power supply agreements in place for the first half of 2016	80.00%
Percentage of standard service customers with wholesale power supply agreements in place for the second half of 2016	30.00%
Collateral required to be posted if the entity's credit rating declined two ratings to fall below investment grade | $	$ 10
Standard & Poor's [Member]
Power Supply Arrangements [Abstract]
Number of changes in credit rating on senior debt to be placed on negative credit watch	1
Number of changes in credit rating on senior debt to fall below investment grade	2
Moody's [Member]
Power Supply Arrangements [Abstract]
Number of changes in credit rating on senior debt to be placed on negative credit watch	2
Number of changes in credit rating on senior debt to fall below investment grade	3

REGULATORY PROCEEDINGS, New Ren

REGULATORY PROCEEDINGS, New Renewable Source Generation (Details) - DEEP [Member] - Renewable Energy Contracts [Member]	9 Months Ended
	Sep. 30, 2015Contract
New Renewable Source Generation [Abstract]
Number of contracts for energy and/or RECs	2
Percentage of distribution load represented by quantity of energy and RECs to be purchased	3.50%

REGULATORY PROCEEDINGS, Transmi

REGULATORY PROCEEDINGS, Transmission (Details) - United Illuminating Company (UI) [Member] $ in Millions	Oct. 16, 2014	Sep. 30, 2015USD ($)	Sep. 30, 2011	Sep. 30, 2014Complaint	Dec. 31, 2014
Minimum [Member]
Transmission [Abstract]
Weighted average return on equity		11.30%
Maximum [Member]
Transmission [Abstract]
Weighted average return on equity		11.40%
FERC [Member]
Transmission [Abstract]
Number of complaints | Complaint				3
Refund period		15 months
FERC [Member] | First Complaint [Member]
Transmission [Abstract]
Current approved base return on equity			11.14%
Reasonable Base Return on equity	10.57%
FERC [Member] | First Complaint [Member] | Minimum [Member]
Transmission [Abstract]
Reasonable Base Return on equity					10.57%
FERC [Member] | First Complaint [Member] | Maximum [Member]
Transmission [Abstract]
Reasonable Base Return on equity					11.74%
FERC [Member] | Third Complaint [Member]
Transmission [Abstract]
Refund amount held for reserve		$ 3.4
FERC [Member] | All Three Complaints [Member]
Transmission [Abstract]
Net pre-tax reserves relating to refunds and potential refunds		5.1
Cumulative reserves recorded for refund		11.5
Amount of reserve refunded		$ 6.4

REGULATORY PROCEEDINGS, New Eng

REGULATORY PROCEEDINGS, New England East-West Solution (Details) - CL&P Agreement [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)Project	Sep. 30, 2014USD ($)
New England East-West Solution [Abstract]
Number of inter related transmission projects | Project		4
Number of inter-related transmission projects with portions sited in Connecticut | Project		3
Minimum amount of entity's investment for ownership of specific transmission assets		$ 60
Threshold percentage of CL&P's costs for the Connecticut portions of projects		8.40%
Approximate investment rights		$ 45
Aggregate deposits since inception of agreement		45
Pre-tax income earned on each deposit in NEEWS project	$ 0.5	1.2	$ 1.2
GSRP [Member]
New England East-West Solution [Abstract]
Value of transferred assets		24.6
IRP [Member]
New England East-West Solution [Abstract]
Value of transferred assets		$ 20

REGULATORY PROCEEDINGS, Other P

REGULATORY PROCEEDINGS, Other Proceedings (Details) - United Illuminating Company (UI) [Member] $ in Millions	Nov. 12, 2014USD ($)
GSC/NBFMCC Proceeding [Member]
Other Proceedings [Abstract]
Amount approved for recovery	$ 7.7
Total estimated loss	11.3
Pre-tax write-off	3.8
CTA Reconciliation Proceeding [Member]
Other Proceedings [Abstract]
Remaining CTA regulatory liability	8.2
CTA Reconciliation Proceeding [Member] | Connecticut Yankee Atomic Power Company Litigation [Member]
Other Proceedings [Abstract]
Regulatory liability related to CT Yankee DOE litigation	$ 12

REGULATORY PROCEEDINGS, Gas Dis

REGULATORY PROCEEDINGS, Gas Distribution (Details) $ in Millions	Jan. 22, 2014USD ($)Mechanism	Sep. 30, 2015USD ($)
Connecticut Natural Gas Corporation (CNG) [Member]
Gas Distribution Rates [Abstract]
Return on equity, approved	9.18%	9.18%
Number of decoupling mechanisms | Mechanism	1
Number of rate making mechanisms | Mechanism	2
Earnings share mechanism ratio	50/50
Connecticut Natural Gas Corporation (CNG) [Member] | Minimum [Member]
Gas Distribution Rates [Abstract]
Decrease in annual revenue requirements	$ 2.5
Connecticut Natural Gas Corporation (CNG) [Member] | Maximum [Member]
Gas Distribution Rates [Abstract]
Decrease in annual revenue requirements	$ 3.5
Connecticut Natural Gas Corporation (CNG) [Member] | Expansion Plan [Member]
Other Proceedings [Abstract]
Duration of expansion plan		10 years
Credit to customer		$ 10.8
Southern Connecticut Gas Company (SCG) [Member]
Gas Distribution Rates [Abstract]
Return on equity, approved		9.36%
Berkshire Gas Company [Member]
Gas Distribution Rates [Abstract]
Return on equity, approved		10.50%
Duration of approved rate plan		10 years

SHORT-TERM CREDIT ARRANGEMENTS

SHORT-TERM CREDIT ARRANGEMENTS (Details) $ in Millions	Sep. 30, 2015USD ($)
Revolving Credit Facility [Member]
Disclosure of short-term credit arrangements [Abstract]
Amounts outstanding under the Credit Facility	$ 85
Available credit under the Credit Facility	310.6
Standby Letters of Credit [Member]
Disclosure of short-term credit arrangements [Abstract]
Standby letters of credit outstanding	$ 4.4

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
INCOME TAXES [Abstract]
Increase in income tax expense	$ 1,800			$ 8,300
Income tax expense	$ 6,811		$ 4,986	$ 43,566	$ 35,276
Effective book income tax rates (in hundredths)				32.90%	32.90%
Income tax expense adjustment		$ 1,100

SUPPLEMENTARY INFORMATION (Deta

SUPPLEMENTARY INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Depreciation and Amortization [Abstract]
Property, plant and equipment depreciation	$ 37,081	$ 32,860	$ 106,185	$ 97,208
Amortization of regulatory assets	3,534	2,718	17,094	15,200
Total Depreciation and Amortization	40,615	35,578	123,279	112,408
Taxes - Other than Income Taxes - Operating [Abstract]
Connecticut gross earnings	18,180	16,199	56,353	54,671
Local real estate and personal property	14,085	13,310	40,080	37,399
Payroll taxes	2,886	3,046	11,064	9,877
Other	45	342	848	1,027
Total Taxes - Other than Income Taxes	35,196	32,897	108,345	102,974
Other Income and (Deductions) [Abstract]
Interest income	77	666	1,458	1,731
Allowance for funds used during construction - equity	2,589	1,949	6,698	6,869
Allowance for funds used during construction - debt	1,292	1,201	3,424	4,032
Weather insurance	0	0	0	(2,437)
Other	263	520	1,303	2,627
Total Other Income and (Deductions)	$ 4,221	$ 4,336	$ 12,883	$ 12,822

PENSION AND OTHER BENEFITS (Det

PENSION AND OTHER BENEFITS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension contributions			$ 15,000
Additional contribution during remainder of 2015			0
Pension Benefit [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 3,605	$ 2,896	10,815	$ 8,688
Interest cost	10,505	11,019	31,515	33,057
Expected return on plan assets	(14,120)	(13,560)	(42,360)	(40,680)
Amortization of prior service costs	48	73	144	219
Amortization of actuarial (gain) loss	4,845	3,097	14,535	9,291
Net periodic benefit cost	$ 4,883	$ 3,525	$ 14,649	$ 10,575
Pension Benefit [Member] | Minimum [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.20%	4.90%	4.20%	4.90%
Average wage increase	3.50%	3.50%	3.50%	3.50%
Return on plan assets	7.75%	7.75%	7.75%	7.75%
Pension Benefit [Member] | Maximum [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.30%	5.20%	4.30%	5.20%
Average wage increase	3.80%	3.80%	3.80%	3.80%
Return on plan assets	8.00%	8.00%	8.00%	8.00%
Other Postretirement Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 393	$ 404	$ 1,179	$ 1,212
Interest cost	1,327	1,487	3,981	4,461
Expected return on plan assets	(690)	(700)	(2,070)	(2,100)
Amortization of prior service costs	75	71	225	213
Amortization of actuarial (gain) loss	176	(172)	528	(516)
Net periodic benefit cost	$ 1,281	$ 1,090	$ 3,843	$ 3,270
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Composite health care trend rate (current year)	7.00%	7.00%	7.00%	7.50%
Composite health care trend rate (2019 forward)	5.00%	5.00%	5.00%	5.00%
Other Postretirement Benefits [Member] | Minimum [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.20%	4.85%	4.20%	4.85%
Return on plan assets	5.56%	5.56%	5.56%	5.56%
Other Postretirement Benefits [Member] | Maximum [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.30%	5.20%	4.30%	5.20%
Return on plan assets	8.00%	8.00%	8.00%	8.00%

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Director of UIL Holdings [Member] | Lease Payments for Office Space [Member]
Related Party Transaction [Line Items]
Lease payments for office space	$ 0.4	$ 0.4	$ 1.1	$ 1.4

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	Jun. 30, 2014	Nov. 30, 2013	Sep. 03, 2013	Jul. 31, 2013	May. 31, 2012	Apr. 30, 2015	Sep. 30, 2015	Jun. 30, 2015
Connecticut Yankee Atomic Power Company [Member]
Litigation Settlement [Abstract]
Percentage of ownership in equity method investment								9.50%
Carrying value of equity method investment								$ 0.2
United Illuminating Company (UI) [Member] | Middletown/Norwalk Transmission Projects [Member]
Litigation Settlement [Abstract]
Damages awarded and paid to plaintiff			$ 1.3
United Illuminating Company (UI) [Member] | New Haven Harbor Station Site [Member]
Site Decontamination, Demolition and Remediation Costs [Abstract]
Site contingency, liability accrued							$ 3.2
United Illuminating Company (UI) [Member] | English Station Site [Member]
Site Decontamination, Demolition and Remediation Costs [Abstract]
Estimated remediation costs							30
United Illuminating Company and Connecticut Yankee Atomic Power Company [Member] | DOE Spent Fuel Litigation [Member]
Litigation Settlement [Abstract]
Litigation, amount awarded	$ 12	$ 126.3		$ 3.8	$ 39.7
Loss contingency damage claims						$ 32.9
Contingent award amount						$ 3.1
Berkshire Gas Company [Member] | Mill Street Greenfield Massachusetts Site [Member]
Site Decontamination, Demolition and Remediation Costs [Abstract]
Site contingency, liability accrued							0.9
Berkshire Gas Company [Member] | East Street Site Pittsfield Massachusetts [Member]
Site Decontamination, Demolition and Remediation Costs [Abstract]
Site contingency, liability accrued							$ 3.2

FAIR VALUE MEASUREMENTS, Fair V

FAIR VALUE MEASUREMENTS, Fair Value of Financial Assets and Liabilities (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Assets [Abstract]
Derivative assets	$ 31,516	$ 27,270
Noncurrent investments	13,141	11,387
Deferred Compensation Plan	3,529	3,624
Supplemental retirement benefit trust life insurance policies	8,254	8,498
Total financial assets, fair value	56,440	50,779
Liabilities [Abstract]
Derivative liabilities	102,958	85,074
Long-term debt	1,908,931	1,941,711
Total financial liabilities, fair value	2,011,889	2,026,785
Net fair value assets/(liabilities)	(1,955,449)	(1,976,006)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Derivative assets	0	0
Noncurrent investments	13,141	11,387
Deferred Compensation Plan	3,529	3,624
Supplemental retirement benefit trust life insurance policies	0	0
Total financial assets, fair value	16,670	15,011
Liabilities [Abstract]
Derivative liabilities	0	0
Long-term debt	0	0
Total financial liabilities, fair value	0	0
Net fair value assets/(liabilities)	16,670	15,011
Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Derivative assets	0	0
Noncurrent investments	0	0
Deferred Compensation Plan	0	0
Supplemental retirement benefit trust life insurance policies	8,254	8,498
Total financial assets, fair value	8,254	8,498
Liabilities [Abstract]
Derivative liabilities	0	0
Long-term debt	1,908,931	1,941,711
Total financial liabilities, fair value	1,908,931	1,941,711
Net fair value assets/(liabilities)	(1,900,677)	(1,933,213)
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Derivative assets	31,516	27,270
Noncurrent investments	0	0
Deferred Compensation Plan	0	0
Supplemental retirement benefit trust life insurance policies	0	0
Total financial assets, fair value	31,516	27,270
Liabilities [Abstract]
Derivative liabilities	102,958	85,074
Long-term debt	0	0
Total financial liabilities, fair value	102,958	85,074
Net fair value assets/(liabilities)	$ (71,442)	$ (57,804)

FAIR VALUE MEASUREMENTS, Unobse

FAIR VALUE MEASUREMENTS, Unobservable Input Reconciliation (Details) - Contracts for Differences [Member] - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Minimum [Member]
Unobservable Input [Abstract]
Risk of non-performance range	0.31%	0.00%
Discount rate range	1.37%	1.65%
Forward pricing range (in dollars per MW)	$ 3.15	$ 3.15
Maximum [Member]
Unobservable Input [Abstract]
Risk of non-performance range	0.94%	0.66%
Discount rate range	2.06%	2.25%
Forward pricing range (in dollars per MW)	$ 11.19	$ 14.59

FAIR VALUE MEASUREMENTS, Assets

FAIR VALUE MEASUREMENTS, Assets and Liabilities Classified as Level 3 (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Changes in fair value of assets and liabilities classified as level 3 [Roll Forward]
Net derivative assets/(liabilities), Beginning balance	$ (57,804)
Unrealized gains and (losses), net	(13,638)
Net derivative assets/(liabilities), Ending balance	(71,442)
Change in unrealized gains (losses), net relating to net derivative assets/(liabilities), still held as of September 30, 2015	$ (13,638)

FAIR VALUE MEASUREMENTS, Regula

FAIR VALUE MEASUREMENTS, Regulatory Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Change in regulatory asset/liability balances [Roll Forward]
Net regulatory assets/(liabilities), Beginning balance	$ 57,804
Unrealized (gains) and losses, net	13,638
Net regulatory assets/(liabilities), Ending balance	$ 71,442

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating Revenues		$ 330,524	$ 293,026	$ 1,226,584	$ 1,198,982
Purchased power and gas		73,354	68,776	421,792	446,067
Operation and maintenance		111,286	95,251	315,637	290,828
Transmission wholesale		30,272	25,802	67,969	65,777
Depreciation and amortization		40,615	35,578	123,279	112,408
Taxes, other than income taxes		35,196	32,897	108,345	102,974
Merger and acquisition-related expenses		600	570	7,395	6,090
Operating Income		39,201	34,152	182,167	174,838
Other Income and (Deductions), net		4,221	3,487	12,883	(2,366)
Interest Charges, net		24,387	23,641	72,681	70,322
Income from Equity Investments		3,408	3,492	10,284	10,398
Income (Loss) Before Income Taxes		22,443	17,490	132,653	112,548
Income Taxes		6,811	4,986	43,566	35,276
Net Income (Loss)		15,632	12,504	89,087	77,272
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		6	6	20	(21)
Net Income (Loss) attributable to UIL Holdings		15,626	12,498	89,067	77,293
Total Capital Expenditure	[1]	95,028	70,630	254,197	196,171
Total Assets	[2]	5,172,366		5,172,366		$ 5,111,935
Goodwill		266,205		266,205		266,205
Reporting Segments [Member] | Electric Distribution [Member]
Segment Reporting Information [Line Items]
Operating Revenues		158,587	134,289	481,278	397,384
Purchased power and gas		47,041	37,962	180,858	123,771
Operation and maintenance		55,394	42,819	152,747	135,282
Transmission wholesale		0	0	0	0
Depreciation and amortization		13,554	11,943	40,678	35,902
Taxes, other than income taxes		14,721	14,244	42,963	38,597
Merger and acquisition-related expenses		0	0	0	0
Operating Income		27,877	27,321	64,032	63,832
Other Income and (Deductions), net		1,682	2,877	5,591	9,503
Interest Charges, net		8,789	7,590	24,979	22,661
Income from Equity Investments		3,408	3,492	10,284	10,398
Income (Loss) Before Income Taxes		24,178	26,100	54,928	61,072
Income Taxes		6,032	8,173	14,980	18,015
Net Income (Loss)		18,146	17,927	39,948	43,057
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		0	0	0	0
Net Income (Loss) attributable to UIL Holdings		18,146	17,927	39,948	43,057
Total Capital Expenditure	[1]	0	0	0	0
Total Assets	[3]	0		0		0
Net plant in service		1,343,400		1,343,400		1,283,600
Reporting Segments [Member] | Electric Transmission [Member]
Segment Reporting Information [Line Items]
Operating Revenues		77,767	62,926	195,481	183,715
Purchased power and gas		0	0	0	0
Operation and maintenance		14,838	11,456	42,415	36,049
Transmission wholesale		30,272	25,802	67,969	65,777
Depreciation and amortization		4,475	4,208	13,036	12,635
Taxes, other than income taxes		11,680	10,441	28,216	26,832
Merger and acquisition-related expenses		0	0	0	0
Operating Income		16,502	11,019	43,845	42,422
Other Income and (Deductions), net		375	881	2,925	2,793
Interest Charges, net		3,086	3,375	9,852	9,832
Income from Equity Investments		0	0	0	0
Income (Loss) Before Income Taxes		13,791	8,525	36,918	35,383
Income Taxes		5,374	3,048	14,228	12,262
Net Income (Loss)		8,417	5,477	22,690	23,121
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		0	0	0	0
Net Income (Loss) attributable to UIL Holdings		8,417	5,477	22,690	23,121
Total Capital Expenditure	[1]	0	0	0	0
Total Assets	[3]	0		0		0
Net plant in service		699,700		699,700		659,400
Reporting Segments [Member] | Total Electric Distribution and Transmission [Member]
Segment Reporting Information [Line Items]
Operating Revenues		236,354	197,215	676,759	581,099
Purchased power and gas		47,041	37,962	180,858	123,771
Operation and maintenance		70,232	54,275	195,162	171,331
Transmission wholesale		30,272	25,802	67,969	65,777
Depreciation and amortization		18,029	16,151	53,714	48,537
Taxes, other than income taxes		26,401	24,685	71,179	65,429
Merger and acquisition-related expenses		0	0	0	0
Operating Income		44,379	38,340	107,877	106,254
Other Income and (Deductions), net		2,057	3,758	8,516	12,296
Interest Charges, net		11,875	10,965	34,831	32,493
Income from Equity Investments		3,408	3,492	10,284	10,398
Income (Loss) Before Income Taxes		37,969	34,625	91,846	96,455
Income Taxes		11,406	11,221	29,208	30,277
Net Income (Loss)		26,563	23,404	62,638	66,178
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		0	0	0	0
Net Income (Loss) attributable to UIL Holdings		26,563	23,404	62,638	66,178
Total Capital Expenditure	[1]	41,466	31,523	119,677	91,600
Total Assets	[3]	2,930,013		2,930,013		2,876,792
Reporting Segments [Member] | Gas Distribution [Member]
Segment Reporting Information [Line Items]
Operating Revenues		94,170	94,708	549,825	616,780
Purchased power and gas		27,715	30,504	244,732	321,986
Operation and maintenance		47,805	44,950	137,590	130,761
Transmission wholesale		0	0	0	0
Depreciation and amortization		17,285	16,477	57,545	55,994
Taxes, other than income taxes		8,509	9,082	36,271	37,080
Merger and acquisition-related expenses		0	0	0	0
Operating Income		(7,144)	(6,305)	73,687	70,959
Other Income and (Deductions), net		1,594	702	2,617	(587)
Interest Charges, net		6,723	7,116	20,405	21,320
Income from Equity Investments		0	0	0	0
Income (Loss) Before Income Taxes		(12,273)	(12,719)	55,899	49,052
Income Taxes		(4,862)	(6,229)	20,651	18,749
Net Income (Loss)		(7,411)	(6,490)	35,248	30,303
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		6	6	20	(21)
Net Income (Loss) attributable to UIL Holdings		(7,417)	(6,496)	35,228	30,324
Total Capital Expenditure	[1]	39,744	32,926	93,094	78,278
Total Assets	[2]	2,069,913		2,069,913		2,087,284
Goodwill		266,200		266,200		266,200
Reporting Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues		0	1,103	0	1,103
Purchased power and gas		(1,402)	310	(3,798)	310
Operation and maintenance		(6,751)	(3,974)	(17,115)	(11,264)
Transmission wholesale		0	0	0	0
Depreciation and amortization		5,301	2,950	12,020	7,877
Taxes, other than income taxes		286	(870)	895	465
Merger and acquisition-related expenses		600	570	7,395	6,090
Operating Income		1,966	2,117	603	(2,375)
Other Income and (Deductions), net		570	(973)	1,750	(14,075)
Interest Charges, net		5,789	5,560	17,445	16,509
Income from Equity Investments		0	0	0	0
Income (Loss) Before Income Taxes		(3,253)	(4,416)	(15,092)	(32,959)
Income Taxes		267	(6)	(6,293)	(13,750)
Net Income (Loss)		(3,520)	(4,410)	(8,799)	(19,209)
Less: Preferred Stock Dividends of Subsidiary, Noncontrolling Interests		0	0	0	0
Net Income (Loss) attributable to UIL Holdings		(3,520)	(4,410)	(8,799)	(19,209)
Total Capital Expenditure	[1]	13,818	$ 6,181	41,426	$ 26,293
Total Assets		$ 172,440		$ 172,440		$ 147,859
[1]	Information for segmenting total capital expenditures between Distribution and Transmission is not available. Total Electric Distribution and Transmission capital expenditures are disclosed in the Total Electric Distribution and Transmission column.
[2]	Includes $266.2 million of goodwill in the Gas Distribution segment as of September 30, 2015 and December 31, 2014.
[3]	Information for segmenting total assets between Distribution and Transmission is not available. Total Electric Distribution and Transmission assets are disclosed in the Total Electric and Distribution and Transmission column. Net plant in service is segregated by segment and, as of September 30, 2015, was $1,343.4 million and $699.7 million for Distribution and Transmission, respectively. As of December 31, 2014, net plant in service was $1,283.6 million and $659.4 million for Distribution and Transmission, respectively.