XML 21 R10.htm IDEA: XBRL DOCUMENT
v3.25.1

Summary of Significant Accounting Policies | 3 Months Ended
--- | ---
Mar. 31, 2025
Accounting Policies [Abstract] |
Summary of Significant Accounting Policies | Note 1 - Summary of Significant Accounting Policies Nature of Operations - Unitil Corporation (Unitil or the Company) is a public utility holding company. Unitil and its subsidiaries are subject to regulation as a holding company system by the Federal Energy Regulatory Commission (FERC) under the Energy Policy Act of 2005. The following companies are wholly-owned subsidiaries of Unitil: Unitil Energy Systems, Inc. (Unitil Energy), Fitchburg Gas and Electric Light Company (Fitchburg), Northern Utilities, Inc. (Northern Utilities), Bangor Natural Gas Company, (Bangor), Granite State Gas Transmission, Inc. (Granite State), Unitil Power Corp. (Unitil Power), Unitil Realty Corp. (Unitil Realty), Unitil Service Corp. (Unitil Service) and its non-regulated business unit Unitil Resources, Inc. (Unitil Resources). The Company’s earnings historically have been seasonal and typically higher in the first and fourth quarters when customers use gas for heating purposes. Unitil’s principal business is the local distribution of electricity in the southeastern seacoast and capital city areas of New Hampshire and the greater Fitchburg area of north central Massachusetts and the local distribution of gas in southeastern New Hampshire, portions of southern Maine to the Lewiston-Auburn area and greater Bangor Area of central Maine and in the greater Fitchburg area of north central Massachusetts. Unitil has four distribution utility subsidiaries, including Unitil Energy, which operates in New Hampshire; Fitchburg, which operates in Massachusetts; Northern Utilities, which operates in New Hampshire and Maine; and Bangor, which operates in Maine (collectively referred to as the “distribution utilities”). Granite State is an interstate gas transmission pipeline company, operating 85 miles of underground gas transmission pipeline primarily located in Maine and New Hampshire. Granite State provides Northern Utilities with interconnection to three major gas pipelines and access to domestic gas supplies in the south and Canadian gas supplies in the north. Granite State derives its revenues principally from transportation services provided to Northern Utilities and, to a lesser extent, third-party marketers. A sixth utility subsidiary, Unitil Power, formerly functioned as the full requirements wholesale power supply provider for Unitil Energy, but ceased being the wholesale supplier of Unitil Energy with the implementation of industry restructuring and divested its long-term power supply contracts. Unitil also has three other wholly-owned subsidiaries: Unitil Service, Unitil Resources and Unitil Realty. Unitil Service provides, at cost, a variety of administrative and professional services, including regulatory, financial, accounting, human resources, engineering, operations, technology, energy management and management services on a centralized basis to its affiliated Unitil companies. Unitil Resources is the Company’s wholly-owned non-regulated subsidiary, which currently does not have any activity. Unitil Realty owns and manages the Company’s corporate office in Hampton, New Hampshire and leases this facility to Unitil Service under a long-term lease arrangemen t. Unitil Realty also owns land on which Unitil Energy’s Kingston solar project is located in Kingston, New Hampshire. Basis of Presentation - The accompanying unaudited consolidated financial statements of Unitil have been prepared in accordance with the instructions to Form 10-Q and include the information and footnotes required by generally accepted accounting principles. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. The results of operations for the three months ended March 31, 2025 are not necessarily indicative of results to be expected for the year ending December 31, 2025. For additional information, refer to Note 1 of Part II to the Consolidated Financial Statements – “Summary of Significant Accounting Policies” of the Company’s Form 10-K for the year ended December 31, 2024, as filed with the Securities and Exchange Commission (SEC) on February 10, 2025, for a description of the Company’s Basis of Presentation. Utility Revenue Recognition - Electric Operating Revenues and Gas Operating Revenues consist of billed and unbilled revenue and revenue from rate adjustment mechanisms. Billed and unbilled revenue includes delivery revenue and pass-through revenue, recognized according to tariffs approved by federal and state regulatory commissions, which determine the amount of revenue the Company will record for these items. Revenue from rate adjustment mechanisms is accrued revenue, recognized in connection with rate adjustment mechanisms, and authorized by regulators for recognition in the current period for future cash recoveries from, or credits to, customers. Revenue is recorded when service is rendered or energy is delivered to customers. However, the determination of energy sales to individual customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each calendar month, amounts of energy delivered to customers since the date of the last meter reading are estimated and the corresponding unbilled revenues are calculated. These unbilled revenues are estimated each month based on estimated customer usage by class and applicable customer rates, taking into account current and historical weather data, assumptions pertaining to metering patterns, billing cycle statistics, and other estimates and assumptions, and are then reversed in the following month when billed to customers. A majority of the Company’s revenue from contracts with customers continues to be recognized on a monthly basis based on applicable tariffs and customer monthly consumption. Such revenue is recognized using the invoice practical expedient, which allows an entity to recognize revenue in the amount that directly corresponds to the value transferred to the customer. The Company’s billed and unbilled revenue meets the definition of “revenues from contracts with customers” as defined in Accounting Standards Codification (ASC) 606. Revenue recognized in connection with rate adjustment mechanisms is consistent with the definition of alternative revenue programs in ASC 980-605-25-3, as the Company has the ability to adjust rates in the future as a result of past activities or completed events. The rate adjustment mechanisms meet the criteria within ASC 980-605-25-4. In cases where allowable costs are greater than operating revenues billed in the current period for the individual rate adjustment mechanism, additional operating revenue is recognized. In cases where allowable costs are less than operating revenues billed in the current period for the individual rate adjustment mechanism, operating revenue is reduced. ASC 606 requires the Company to disclose separately the amount of revenues from contracts with customers and alternative revenue program revenues. In the following tables, revenue is classified by the types of goods/services rendered and market/customer type.
|  | Three Months Ended March 31, 2025 |
Electric and Gas Operating Revenues (millions): |  | Electric |  |  | Gas |  |  | Total |
Billed and Unbilled Revenue: |  |  |  |  |  |  |  |  |
Residential |  | $ | 33.2 |  |  | $ | 55.8 |  |  | $ | 89.0 |
Commercial and Industrial |  |  | 23.4 |  |  |  | 70.3 |  |  |  | 93.7 |
Other |  |  | 4.2 |  |  |  | 8.2 |  |  |  | 12.4 |
Total Billed and Unbilled Revenue |  |  | 60.8 |  |  |  | 134.3 |  |  |  | 195.1 |
Rate Adjustment Mechanism Revenue |  |  | (0.6 | ) |  |  | (23.7 | ) |  |  | (24.3 | )
Total Electric and Gas Operating Revenues |  | $ | 60.2 |  |  | $ | 110.6 |  |  | $ | 170.8 |
|  | Three Months Ended March 31, 2024 |
Electric and Gas Operating Revenues (millions): |  | Electric |  |  | Gas |  |  | Total |
Billed and Unbilled Revenue: |  |  |  |  |  |  |  |  |
Residential |  | $ | 40.5 |  |  | $ | 41.1 |  |  | $ | 81.6 |
Commercial and Industrial |  |  | 28.1 |  |  |  | 55.2 |  |  |  | 83.3 |
Other |  |  | 2.4 |  |  |  | 4.1 |  |  |  | 6.5 |
Total Billed and Unbilled Revenue |  |  | 71.0 |  |  |  | 100.4 |  |  |  | 171.4 |
Rate Adjustment Mechanism Revenue |  |  | 2.6 |  |  |  | 4.7 |  |  |  | 7.3 |
Total Electric and Gas Operating Revenues |  | $ | 73.6 |  |  | $ | 105.1 |  |  | $ | 178.7 |
Revenue decoupling is the term given to the elimination of the dependency of a utility’s distribution revenue on the volume of electricity or gas sales. The difference between distribution revenue amounts billed to customers and the targeted revenue decoupling amounts is recognized as an increase or a decrease in Accrued Revenue, which forms the basis for resetting rates for future cash recoveries from, or credits to, customers. These revenue decoupling targets may be adjusted as a result of rate cases and other authorized adjustments that the Company files with the Massachusetts Department of Public Utilities (MDPU) and New Hampshire Public Utilities Commission (NHPUC). The Company's electric and gas sales in Massachusetts and New Hampshire are now largely decoupled. Income Taxes - The Company is subject to Federal and State income taxes and various other business taxes. The Company’s process for determining income tax amounts involves estimating the Company’s current tax liabilities, and assessing temporary and permanent differences resulting from the timing of the deductions of expenses and recognition of taxable income for tax and book accounting purposes. These temporary differences result in deferred tax assets and liabilities, which are included in the Company’s Consolidated Balance Sheets. The Company accounts for income tax assets, liabilities and expenses in accordance with the Financial Accounting Standards Board (FASB) Codification guidance on Income Taxes. The Company classifies penalties and interest expense related to income tax liabilities as income tax expense and interest expense, respectively, in the Consolidated Statements of Earnings. Provisions for income taxes are calculated in each jurisdiction in which the Company operates, for each period for which a statement of earnings is presented. The Company accounts for income taxes in accordance with the FASB Codification guidance on Income Taxes, which requires an asset and liability approach for the financial accounting and reporting of income taxes. Significant judgments and estimates are required in determining the current and deferred tax assets and liabilities. The Company’s deferred tax assets and liabilities reflect its best assessment of estimated future taxes to be paid. In accordance with the FASB Codification, the Company periodically assesses the realization of its deferred tax assets and liabilities and adjusts the income tax provision, the current tax liability and deferred taxes in the period in which the facts and circumstances which gave rise to the revision become known. Cash and Cash Equivalents - Cash and Cash Equivalents includes all cash and cash equivalents to which the Company has legal title. Cash equivalents include short-term investments with original maturities of three months or less and interest bearing deposits. The Company’s cash and cash equivalents are held at financial institutions and at times may exceed federally insured limits. The Company has not experienced any losses in such accounts. Under the Independent System Operator—New England (ISO-NE) Financial Assurance Policy (Policy), Unitil’s subsidiaries Unitil Energy, Fitchburg and Unitil Power are required to provide assurance of their ability to satisfy their obligations to ISO-NE. Under this Policy, Unitil’s subsidiaries provide cash deposits covering approximately 2-1/2 months of outstanding obligations, less credit amounts that are b ased on the Company’s credit rating. As of March 31, 2025, March 31, 2024 and December 31, 2024, the Unitil subsidiaries had deposited $6.6 million, $3.1 million and $5.0 million, respectively to satisfy their ISO-NE obligations. Allowance for Doubtful Accounts - The Company recognizes a provision for doubtful accounts that reflects the Company’s estimate of expected credit losses for electric and gas utility service accounts receivable. The allowance for doubtful accounts is calculated by applying a historical loss rate to customer account balances, and reflects management’s assessment of current and expected economic conditions, customer trends, or other factors such as the extent and duration of any shutoff or collection moratoriums. The Company also calculates the amount of written-off receivables that are recoverable through regulatory rate reconciling mechanisms. The Company’s distribution utilities are authorized by regulators to recover the costs of the energy commodity portion of bad debts through rate mechanisms. Also, the electric and gas divisions of Fitchburg are authorized to recover through rates past due amounts associated with protected hardship accounts. Evaluating the adequacy of the allowance for doubtful accounts requires judgment about the assumptions used in the analysis. The Company’s experience has been that the assumptions used in evaluating the adequacy of the allowance for doubtful accounts have proven to be reasonably accurate. The Allowance for Doubtful Accounts as of March 31, 2025, March 31, 2024 and December 31, 2024, was as follows:
|  | March 31, |  |  | December 31, |
(millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Allowance for Doubtful Accounts |  | $ | 2.9 |  |  | $ | 2.8 |  |  | $ | 2.4 |
Accounts Receivable, Net includes $2.8 million, $2.7 million, and $2.3 million of the Allowance for Doubtful Accounts at March 31, 2025, March 31, 2024 and December 31, 2024, respectively. Unbilled Revenues, net (a component of Accrued Revenue) includes $0.1 million, $0.1 million and $0.1 million of the Allowance for Doubtful Accounts at March 31, 2025, March 31, 2024 and December 31, 2024, respectively. Accrued Revenue - Accrued Revenue includes the current portion of Regulatory Assets and unbilled revenues. The following table shows the components of Accrued Revenue as of March 31, 2025, March 31, 2024 and December 31, 2024.
|  | March 31, |  |  | December 31, |
Accrued Revenue (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Regulatory Assets – Current |  | $ | 53.7 |  |  | $ | 65.1 |  |  | $ | 70.1 |
Unbilled Revenues, net |  |  | 6.8 |  |  |  | 7.1 |  |  |  | 7.3 |
Total Accrued Revenue |  | $ | 60.5 |  |  | $ | 72.2 |  |  | $ | 77.4 |
Exchange Gas Receivable - Northern Utilities and Fitchburg have gas exchange and storage agreements whereby gas purchases during the months of April through October are delivered to a third party. The third party delivers gas back to the Company during the months of November through March. The exchange and storage gas volumes are recorded at weighted average cost. The following table shows the components of Exchange Gas Receivable as of March 31, 2025, March 31, 2024 and December 31, 2024.
|  | March 31, |  |  | December 31, |
Exchange Gas Receivable (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Northern Utilities |  | $ | 1.4 |  |  | $ | 1.9 |  |  | $ | 6.0 |
Fitchburg |  |  | 0.2 |  |  |  | 0.3 |  |  |  | 0.4 |
Total Exchange Gas Receivable |  | $ | 1.6 |  |  | $ | 2.2 |  |  | $ | 6.4 |
Gas Inventory - The Company uses the weighted average cost methodology to value gas inventory. The following table shows the components of Gas Inventory as of March 31, 2025, March 31, 2024 and December 31, 2024.
|  | March 31, |  |  | December 31, |
Gas Inventory (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Natural Gas |  | $ | — |  |  | $ | — |  |  | $ | 0.2 |
Propane |  |  | 0.3 |  |  |  | 0.2 |  |  |  | 0.4 |
Liquefied Natural Gas & Other |  |  | 0.1 |  |  |  | 0.1 |  |  |  | 0.5 |
Total Gas Inventory |  | $ | 0.4 |  |  | $ | 0.3 |  |  | $ | 1.1 |
Utility Plant - The cost of additions to Utility Plant and the cost of renewals and betterments are capitalized. Cost consists of labor, materials, services and certain indirect construction costs, including an allowance for funds used during construction (AFUDC). The costs of current repairs and minor replacements are charged to appropriate operating expense accounts. The original cost of utility plant retired or otherwise disposed of is charged to the accumulated provision for depreciation. The Company includes in its mass asset depreciation rates, whic h are periodically reviewed as part of its ratemaking proceedings, cost of removal amounts to provide for future negative salvage value. At March 31, 2025, March 31, 2024 and December 31, 2024, the cost of removal amounts, which are recorded on the Consolidated Balance Sheets in Cost of Removal Obligations, were estimated to be $143.9 million, $130.6 million, and $139.2 million, respectively. Leases - The Company records assets and liabilities on the balance sheet for all leases with terms longer than 12 months. Leases are classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. The Company has elected the practical expedient to not separate non-lease components from lease components and instead to account for both as a single lease component. The Company’s accounting policy election for leases with a lease term of 12 months or less is to recognize the lease payments as lease expense in the Consolidated Statements of Earnings on a straight-line basis over the lease term. See additional discussion in the “Leases” section of Note 4 (Debt and Financing Arrangements). Regulatory Accounting - The Company’s principal business is the distribution of electricity and natural gas. Unitil Energy and Fitchburg are subject to regulation by the FERC. Fitchburg is also regulated by the MDPU, Unitil Energy is regulated by the NHPUC, Northern Utilities is regulated by the Maine Public Utility Commission (MPUC) and NHPUC, and Bangor is regulated by the MPUC. Granite State, the Company’s natural gas transmission pipeline, is regulated by the FERC. Accordingly, the Company uses the Regulated Operations guidance as set forth in the FASB Codification. The Company has recorded Regulatory Assets and Regulatory Liabilities which will be recovered from customers, or applied for customer benefit, in accordance with rate provisions approved by the applicable public utility regulatory commission. The electric and gas divisions of Fitchburg are authorized to recover through rates past due amounts associated with hardship accounts that are protected from shut-off. As of March 31, 2025, March 31, 2024 and December 31, 2024, the Company has recorded $8.2 million, $6.9 million and $7.9 million, respectively, of hardship accounts in Regulatory Assets. These amounts are included in “Other Deferred Charges” in the following table. The Company currently receives recovery in rates or expects to receive recovery of these hardship accounts in future rate cases.
|  | March 31, |  |  | December 31, |
Regulatory Assets consist of the following (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Retirement Benefits |  | $ | 19.5 |  |  | $ | 27.4 |  |  | $ | 14.4 |
Energy Supply and Other Rate Adjustment Mechanisms |  |  | 49.1 |  |  |  | 62.3 |  |  |  | 65.4 |
Deferred Storm Charges |  |  | 7.7 |  |  |  | 7.8 |  |  |  | 8.3 |
Environmental |  |  | 9.4 |  |  |  | 6.2 |  |  |  | 9.4 |
Income Taxes |  |  | 0.9 |  |  |  | 0.9 |  |  |  | 0.4 |
Other Deferred Charges |  |  | 14.3 |  |  |  | 12.6 |  |  |  | 14.1 |
Total Regulatory Assets |  |  | 100.9 |  |  |  | 117.2 |  |  |  | 112.0 |
Less: Current Portion of Regulatory Assets(1) |  |  | 53.7 |  |  |  | 65.1 |  |  |  | 70.1 |
Regulatory Assets – noncurrent |  | $ | 47.2 |  |  | $ | 52.1 |  |  | $ | 41.9 |
(1) Reflects amounts included in the Accrued Revenue on the Company’s Consolidated Balance Sheets.
|  | March 31, |  |  | December 31, |
Regulatory Liabilities consist of the following (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Income Taxes (Note 8) |  | $ | 50.3 |  |  | $ | 37.9 |  |  | $ | 50.4 |
Rate Adjustment Mechanisms & Other |  |  | 20.4 |  |  |  | 14.0 |  |  |  | 13.6 |
Retirement Benefits |  |  | 5.8 |  |  |  | — |  |  |  | — |
Total Regulatory Liabilities |  |  | 76.5 |  |  |  | 51.9 |  |  |  | 64.0 |
Less: Current Portion of Regulatory Liabilities |  |  | 23.8 |  |  |  | 17.9 |  |  |  | 17.2 |
Regulatory Liabilities – noncurrent |  | $ | 52.7 |  |  | $ | 34.0 |  |  | $ | 46.8 |
Generally, the Company receives a return on investment on its regulatory assets for which a cash outflow has been made. Included in Regulatory Assets as of March 31, 2025 are $7.3 million of environmental costs, rate case costs and other expenditures to be recovered over varying periods in the next seven years. Regulators have authorized recovery of these expenditures, but without a return. Regulatory commissions can reach different conclusions about the recovery of costs, which can have a material effect on the Company’s Consolidated Financial Statements. The Company believes it is probable that its regulated distribution and transmission utilities will recover their investments in long-lived assets, including regulatory assets. If the Company, or a portion of its assets or operations, were to cease meeting the criteria for application of these accounting rules, accounting standards for businesses in general would become applicable and immediate recognition of any previously deferred costs, or a portion of deferred costs, would be required in the year in which the criteria are no longer met, if such deferred costs were not recoverable in the portion of the business that continues to meet the criteria for application of the FASB Codification topic on Regulated Operations. If unable to continue to apply the FASB Codification provisions for Regulated Operations, the Company would be required to apply the provisions for the Discontinuation of Rate-Regulated Accounting included in the FASB Codification. In the Company’s opinion, its regulated operations will be subject to the FASB Codification provisions for Regulated Operations for the foreseeable future. Derivatives - The Company’s regulated energy subsidiaries enter into energy supply contracts to serve their electric and gas customers. The Company has determined that its energy supply contracts either do not qualify as a derivative instrument under the guidance set forth in the FASB Codification, have been elected as a normal purchase, or have contingencies that have not yet been met in order to establish a notional amount. Fitchburg has entered into power purchase agreements for which contingencies exist (see Note 6, Regulatory Matters—Fitchburg— Massachusetts Request for Proposal (RFPs)). Until these contingencies are satisfied, these contracts will not qualify for derivative accounting. The Company believes that the power purchase obligations under these long-term contracts will have a material effect on the contractual obligations of Fitchburg. Investments in Marketable Securities - The Company maintains a trust through which it invests in a money market fund. This fund is intended to satisfy obligations under the Company’s Supplemental Executive Retirement Plan (SERP) (See additional discussion of the SERP in Note 9). At March 31, 2025, March 31, 2024 and December 31, 2024, the fair value of the Company’s investments in these trading securities, which are recorded on the Consolidated Balance Sheets in Other Assets, was $6.1 million, $5.9 million and $6.3 million, respectively, as shown in the following table. These investments are valued based on quoted prices from active markets and are categorized in Level 1 as they are actively traded and no valuation adjustments have been applied. Changes in the fair value of these investments are recorded in Other Expense, Net.
|  | March 31, |  |  | December 31, |
Fair Value of Marketable Securities (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Money Market Funds |  | $ | 2.0 |  |  | $ | 2.0 |  |  | $ | 2.5 |
Fixed Income Funds |  |  | 4.1 |  |  |  | 3.9 |  |  |  | 3.8 |
Total Marketable Securities |  | $ | 6.1 |  |  | $ | 5.9 |  |  | $ | 6.3 |
The Company also sponsors the Unitil Corporation Deferred Compensation Plan (the “DC Plan”). The DC Plan is a non-qualified deferred compensation plan that provides a vehicle for participants to accumulate tax-deferred savings to supplement retirement income. The DC Plan, which was effective January 1, 2019, is open to senior management or other highly compensated employees as determined by the Company’s Board of Directors, and may also be used for recruitment and retention purposes for newly hired senior executives. The DC Plan design mirrors the Company’s Tax Deferred Savings and Investment Plan formula, but provides for contributions on compensation above the IRS limit, which will allow participants to defer up to 85% of base salary, and up to 85% of any cash incentive for retirement. The Company may also elect to make discretionary contributions on behalf of any participant in an amount determined by the Company’s Board of Directors. A trust has been established to invest the funds associated with the DC Plan. At March 31, 2025, March 31, 2024 and December 31, 2024, the fair value of the Company’s investments in these trading securities related to the DC Plan, which are recorded on the Consolidated Balance Sheets in Other Assets, were $2.5 million, $1.8 million and $2.2 million, respectively, as shown in the following table. These investments are valued based on quoted prices from active markets and are categorized in Level 1 as they are actively traded and no valuation adjustments have been applied. Changes in the fair value of these investments are recorded in Other Expense, Net.
|  | March 31, |  |  | December 31, |
Fair Value of Marketable Securities (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Equity Funds |  | $ | 2.3 |  |  | $ | 1.6 |  |  | $ | 2.0 |
Fixed Income Funds |  |  | 0.1 |  |  |  | 0.1 |  |  |  | 0.1 |
Money Market Funds |  |  | 0.1 |  |  |  | 0.1 |  |  |  | 0.1 |
Total Marketable Securities |  | $ | 2.5 |  |  | $ | 1.8 |  |  | $ | 2.2 |
Energy Supply Obligations - The following discussion and table summarize the nature and amounts of the items recorded as Energy Supply Obligations (current portion) and Other Noncurrent Liabilities (noncurrent portion) on the Company’s Consolidated Balance Sheets.
|  | March 31, |  |  | December 31, |
Energy Supply Obligations (millions) |  | 2025 |  |  | 2024 |  |  | 2024 |
Current: |  |  |  |  |  |  |  |  |
Exchange Gas Obligation |  | $ | 2.9 |  |  | $ | 1.9 |  |  | $ | 6.0 |
Renewable Energy Portfolio Standards |  |  | 3.3 |  |  |  | 5.1 |  |  |  | 4.0 |
Total Energy Supply Obligations |  | $ | 6.2 |  |  | $ | 7.0 |  |  | $ | 10.0 |
Exchange Gas Obligation - Northern Utilities enters into gas exchange agreements under which Northern Utilities releases certain gas pipeline and storage assets, sells the gas storage inventory to an asset manager and subsequently repurchases the inventory over the course of the gas heating season at the same price at which it sold the gas inventory to the asset manager. The gas inventory related to these agreements is recorded in Exchange Gas Receivable on the Company’s Consolidated Balance Sheets while the corresponding obligations are recorded in Energy Supply Obligations. Renewable Energy Portfolio Standards - Renewable Energy Portfolio Standards (RPS) require retail electricity suppliers, including public utilities, to demonstrate that required percentages of their sales are met with power generated from certain types of resources or technologies. Compliance is demonstrated by purchasing and retiring Renewable Energy Certificates (REC) generated by facilities approved by the state as qualifying for REC treatment. Unitil Energy and Fitchburg purchase RECs in compliance with RPS legislation in New Hampshire and Massachusetts for supply provided to default service customers. RPS compliance costs are a supply cost that is recovered in customer default service rates. Unitil Energy and Fitchburg collect RPS compliance costs from customers throughout the year and demonstrate compliance for each calendar year on the following July 1. Due to timing differences between collection of revenue from customers and payment of REC costs to suppliers, Unitil Energy and Fitchburg typically defer costs for RPS compliance which are recorded within Accrued Revenue with a corresponding liability in Energy Supply Obligations on the Company’s Consolidated Balance Sheets. ﻿ Fitchburg has entered into long-term renewable contracts for the purchase of clean energy and/or RECs pursuant to Massachusetts legislation. The generating facilities associated with ten of these contracts have been constructed and are now operating. Three approved contracts are currently under development. These include long-term contracts filed with the MDPU in 2018, two for offshore wind generation (totaling 1,200 MW) and one for imported hydroelectric power and associated transmission, all three of which were approved in 2019. Four offshore wind contracts, totaling 2,400 MW, previously solicited for pursuant to the Green Communities Act and approved by the MDPU in 2021 and 2022, were subsequently terminated in 2023. In compliance with the Green Communities Act as amended by the Energy Diversity Act and the Act Driving Clean Energy and Offshore Wind in coordination with the other electric distribution companies (EDCs) in Massachusetts, on August 30, 2023, the Company issued a fourth offshore wind Request for Proposal seeking to procure at least 400 MW and up to the maximum amount remaining of the statutory requirement. The EDCs received bids for Offshore Wind Generation from three developers as part of a multi-state solicitation with Rhode Island and Connecticut and on September 6, 2024, the Department of Energy Resources selected a portfolio of projects totaling 2,678 MW from three projects. On December 20, 2024, Connecticut announced it was pulling out of contract negotiations as the 800 MW selected by Massachusetts was conditioned upon Connecticut selecting the remaining 400 MW of its 1,200 MW project. Contract negotiations with the remaining two developers are scheduled to be completed by June 30, 2025. In December 2024, the Massachusetts Legislature approved “An Act promoting a clean energy grid, advancing equity, and protecting ratepayers” which, among other provisions, extends the period for long-term renewable contracts up to 30 years and directs the EDCs to “jointly and competitively solicit proposals for energy storage systems and enter into cost-effective long-term contracts equal to, in the aggregate, approximately 5,000 megawatts of energy storage systems not later than July 31, 2030.” The first solicitation will be for the environmental attributes associated with approximately 1,500 megawatts of mid-duration storage to be procured by July 31, 2025. Recently Issued Pronouncements - In December 2023, the FASB issued ASU 2023-09, Income Taxes - Improvements to Income Tax Disclosures (ASU 2023-09). ASU 2023-09 establishes new income tax disclosure requirements in addition to modifying and eliminating certain existing requirements. The amendments in ASU 2023-09 are effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company does not expect this new guidance to have a material effect on the Company’s Consolidated Financial Statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting – Improvements to Reportable Segment Disclosures (ASU 2023-07). The amendments in ASU 2023-07 are intended to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments in ASU 2023-07 are effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company adopted this new guidance for the year-ended December 31, 2024 and it did not have a material effect on the Company’s Consolidated Financial Statements (see Note 3, Segment Information). Acquisition of Bangor Natural Gas Company - On January 31, 2025, the Company acquired all issued and outstanding shares of Bangor Natural Gas Company for $71.2 million, which includes an estimated working capital adjustment. Through this acquisition, the company expanded its service territory to include approximately 8,500 customers in the greater Bangor area of central Maine. In connection with this acquisition, the Company recorded $66.7 million of net utility plant, $5.4 working capital, and $0.9 noncurrent regulatory liabilities. The amounts recorded in conjunction with the acquisition are preliminary, and subject to adjustment based on contractual provisions and purchase accounting adjustments. The financial results associated with this acquisition are included within the gas segment. The operating revenues and net income of this acquisition were not material to the consolidated results for the three months ended March 31, 2025. In connection with Unitil’s acquisition of Bangor, the Company entered into a Transition Services Agreement dated January 31, 2025 between Bangor and Hope Utilities, Inc. (Hope Utilities). Pursuant to the Transition Services Agreement, Hope Utilities will provide Bangor with certain services at cost, for up to 12 months, in order to continue the operation and maintenance of Bangor substantially consistent with past practices until Unitil has completed the successful transition. Subsequent Events - The Company evaluates all events or transactions through the date of the related filing. During the period through the date of this filing, the Company did not have any material subsequent events, other than the acquisition of Maine Natural as noted above, that would result in adjustment to or disclosure in its Consolidated Financial Statements. Acquisition of Maine Natural Gas Company - On March 31, 2025, Unitil entered into a Stock Purchase Agreement (the “Purchase Agreement”) between the Company and Avangrid Enterprises, Inc. (the “Seller”). Pursuant to, and subject to the terms and conditions of, the Purchase Agreement, the Company agreed to acquire all of the issued and outstanding shares of capital stock of Maine Natural from the Seller for $86.0 million in cash, subject to certain adjustments as provided in the Purchase Agreement (the “Maine Acquisition”). In connection with the Maine Acquisition, Unitil entered into a Guaranty with Avangrid Networks, Inc. (“Avangrid Networks”), an affiliate of the Seller, pursuant to which Avangrid Networks guarantees the payment of Seller’s obligations under the Purchase Agreement, subject to the terms of the Guaranty. In addition, Unitil entered into a debt commitment letter with The Bank of Nova Scotia, whereby The Bank of Nova Scotia has committed to provide Unitil an $86.0 million senior unsecured delayed-draw term loan facility to fund the Maine Acquisition. The Maine Acquisition is subject to approval by the MPUC and other closing conditions. Acquisition of Aquarion Water Companies - On May 6, 2025, Unitil entered into a definitive agreement to acquire Aquarion Water Company of Massachusetts, Inc., Aquarion Water Company of New Hampshire, Inc., and Abenaki Water Co., Inc. (the Aquarion Companies) from the Aquarion Water Authority, a quasi-public corporation and political subdivision of the State of Connecticut and a standalone, newly created water authority alongside the South Central Connecticut Regional Water Authority subject to certain closing adjustments. The aggregate enterprise value of the sale is approximately $100.0 million, which includes approximately $70.0 million in cash and the assumption of approximately $30.0 million of debt. The transaction is subject to approval by the DPU, the NHPUC and the MPUC.

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for all significant accounting policies of the reporting entity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483426/235-10-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 235 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/235/tableOfContent + Details
Name: | us-gaap_SignificantAccountingPoliciesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration