Background, Organization, and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations. Southwest Gas Holdings, Inc. is a holding company, owning all of the shares of common stock of Southwest Gas Corporation (“Southwest” or the “natural gas operations” segment) and all of the shares of common stock of Centuri Group, Inc. (“Centuri,” or the “utility infrastructure services” segment). In October 2021, Southwest Gas Holdings, Inc. (the “Company”) entered into an agreement with Dominion Energy Questar Corporation, a wholly owned subsidiary of Dominion Energy, Inc., to acquire all equity interests in Dominion Energy Questar Pipeline, LLC and related entities (“Questar Pipelines”). Upon closing, Questar Pipelines will operate as part of a standalone subsidiary of the Company, and will undergo new branding at or subsequent to close. The agreement provides for consideration of $1.545 billion in cash (subject to certain adjustments) and assumption of approximately $430 million of existing long-term debt. The agreement contains certain termination rights, including a mutual termination right exercisable at any time and a unilateral termination right exercisable by either party if certain conditions have not been met by December 31, 2021 (the initial termination date), subject to an extension unilaterally exercisable by either party if certain conditions have not been met, subsequently extending the initial termination date through June 30, 2022. The completion of this transaction is subject to closing conditions, including the expiration or termination of any waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and approval of certain aspects of the transaction by the Federal Communications Commission. The operations to be acquired would further diversify the Company’s business with an expansion of regulated interstate natural gas pipelines and underground storage services as part of the jurisdiction of the Federal Energy Regulatory Commission (the “FERC”), thereby expanding transportation services into Utah, Wyoming, and Colorado. The Company plans to initially fund this acquisition with a new 364-day term loan, followed by permanent financing. See Note 5 – Debt for more information. Southwest is engaged in the business of purchasing, distributing, and transporting natural gas for customers in portions of Arizona, Nevada, and California. Public utility rates, practices, facilities, and service territories of Southwest are subject to regulatory oversight. The timing and amount of rate relief can materially impact results of operations. Natural gas purchases and the timing of related recoveries can materially impact liquidity. Results for the natural gas operations segment are higher during winter periods due to the seasonality incorporated in its regulatory rate structures. Centuri is a comprehensive utility infrastructure services enterprise dedicated to delivering a diverse array of solutions to North America’s gas and electric providers. Centuri derives revenue primarily from installation, replacement, repair, and maintenance of energy distribution systems. Centuri operations are generally conducted under the business names of NPL Construction Co. (“NPL”), NPL Canada Ltd. (“NPL Canada”), New England Utility Constructors, Inc. (“Neuco”), Linetec Services, LLC (“Linetec”), and Riggs Distler & Company, Inc. (“Riggs Distler”). Utility infrastructure services activity is seasonal in most of Centuri’s operating areas. Peak periods are the summer and fall months in colder climate areas, such as the northeastern and midwestern United States (“U.S.”) and in Canada. In warmer climate areas, such as the southwestern and southeastern U.S., utility infrastructure services activity continues year round.
Basis of Presentation	Basis of Presentation. The condensed consolidated financial statements of Southwest Gas Holdings, Inc. and subsidiaries and Southwest included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The year-end condensed balance sheet data was derived from audited financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. No substantive change has occurred with regard to the Company’s business segments on the whole. The preparation of the condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of management, all adjustments, consisting of normal recurring items and estimates necessary for a fair depiction of results for the interim periods, have been made. In association with the novel Coronavirus (“COVID-19”) pandemic environment, utility operations, and to a large extent, utility infrastructure services, were deemed “essential services.” Management has considered the impact of the pandemic and adjusted certain estimates, where relevant, in the preparation of the condensed consolidated financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2020 Annual Report to Stockholders, which is incorporated by reference into the 2020 Form 10-K.
Fair Value Measurements	Fair Value Measurements. Certain assets and liabilities are reported at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. U.S. GAAP states that a fair value measurement should be based on the assumptions that market participants would use in pricing the asset or liability and establishes a fair value hierarchy that ranks the inputs used to measure fair value by their reliability. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to fair values derived from unobservable inputs (Level 3 measurements). Financial assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows: Level 1 – quoted prices (unadjusted) in active markets for identical assets or liabilities that a company has the ability to access at the measurement date. Level 2 – inputs other than quoted prices included within Level 1 that are observable for similar assets or liabilities, either directly or indirectly. Level 3 – unobservable inputs for the asset or liability. Unobservable inputs are used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The Company primarily used quoted market prices and other observable market pricing information in valuing cash and cash equivalents, long-term debt outstanding, and assets of the qualified pension plan and postretirement benefit plans required to be recorded and/or disclosed at fair value.
Cash and Cash Equivalents	Cash and Cash Equivalents. For purposes of reporting consolidated cash flows, cash and cash equivalents include cash on hand and financial instruments with original maturities of three months or less. Such investments are carried at cost, which approximates market value. Cash and cash equivalents of the Company include $55 million of money market fund investments at September 30, 2021, and an insignificant amount at December 31, 2020. The money market fund investments for Southwest were insignificant at both balance sheet dates. These investments fall within Level 2 of the fair value hierarchy, due to the asset valuation methods used by money market funds. Typical non-cash investing activities include customer advances applied as contributions toward utility construction activity, and capital expenditures that were not yet paid as of period-end reporting dates, but rather were included in accounts payable. Typical activities that represent aspects of both non-cash investing and non-cash financing activities relate to right-of-use assets obtained in exchange for lease liabilities (including, at times, lease terminations and modifications). Amounts related to these collective activities were immaterial for the periods presented herein. See also Prepaid and other current assets below.
Intercompany Transactions	Intercompany Transactions. Centuri recognizes revenues generated from contracts with Southwest (see Note 7 – Segment Information). The accounts receivable balance, revenues, and associated profits are included in the condensed consolidated financial statements of the Company and Southwest and were not eliminated during consolidation in accordance with accounting treatment for rate-regulated entities.
Accounts Receivable, net of allowances	Accounts Receivable, net of allowances. Business activity with respect to natural gas utility operations is conducted with customers located within the three-state region of Arizona, Nevada, and California. Southwest’s accounts receivable are short-term in nature with no billing due dates customarily extending beyond one month, with customers’ credit worthiness assessed upon account creation by evaluation of other utility service and related payment history. Southwest lifted the moratorium on disconnection of natural gas service for non-payment in Arizona and Nevada in September 2021, which was initiated (at the same time as a moratorium on late fees) in March 2020 in response to the COVID-19 pandemic. The moratorium on disconnection continues to be in place for California, and is expected to be lifted in the fourth quarter of 2021. Southwest recommenced assessing late fees on past-due balances in Arizona and Nevada in April 2021, and expects to recommence late fees in California in the fourth quarter of 2021. Southwest is actively working with customers experiencing financial hardship by means of flexible payment options. Management continues to monitor expected credit losses in light of the impact of COVID-19. The allowance for uncollectible accounts receivable balances as of September 30, 2021 reflects the expected impact from the pandemic on balances as of that date, including consideration of customers’ ability to pay those amounts that are due. Utility infrastructure services contracts receivable are recorded at face amounts less an allowance for doubtful accounts. Centuri’s customers are generally investment-grade gas and electric utility companies for which Centuri has historically recognized an insignificant amount of write-offs. Centuri has not been significantly impacted, nor does it anticipate it will experience significant difficulty in collecting amounts due, as a result of the current environment surrounding COVID-19 given the nature of its customers. Activity between periods in the allowance for uncollectible accounts and the balances as of the periods presented within the Company’s and Southwest’s financial statements were not material to the condensed consolidated financial statements overall.
Deferred Purchased Gas Costs	Deferred Purchased Gas Costs. The various regulatory commissions have established procedures to enable Southwest to adjust its billing rates for changes in the cost of natural gas purchased. The difference between the current cost of gas purchased and the cost of gas recovered in billed rates is deferred. Generally, these deferred amounts are recovered or refunded within one year. In mid-February 2021, the central U.S. (from south Texas to North Dakota and the eastern Rocky Mountains) experienced extreme cold temperatures, which increased natural gas demand and caused supply issues due to wellhead freeze-offs, power outages, or other adverse operating conditions upstream of Southwest’s distribution systems. These conditions caused daily natural gas prices to reach unprecedented levels. During this time, Southwest secured natural gas supplies, albeit at substantially higher prices, maintaining service to its customers. The incremental cost for these supplies was approximately $250 million, funded using a 364-day $250 million term loan executed in March 2021 (see Note 5 – Debt). The incremental gas costs are expected to continue to be collected from customers through the purchased gas adjustment (“PGA”) mechanisms. Following the extreme weather event, an interstate transmission pipeline company billed Southwest, in addition to customary transmission costs, $65 million (later reduced to approximately $55 million) for pipeline imbalance charges, allegedly incurred during the period of the pipeline’s critical operation condition. However, Southwest formally disputed the imbalance charges, in addition to interest on that amount, believing that no amounts were due to the pipeline. In June 2021, the interstate transmission pipeline company requested approval from the Federal Energy Regulatory Commission (the “FERC”) to waive these imbalance charges and interest, affirming that they had the authority to elect the option to waive the underlying charges based on their tariff, but were seeking approval by the FERC for purposes of transparency and regulatory certainty. In August 2021, FERC approval was received. Consequently, no amounts were recognized by Southwest related to the original charge from the pipeline.
Prepaid and other current assets	Prepaid and other current assets. Prepaid and other current assets includes gas pipe materials and operating supplies of $55 million at September 30, 2021 and $50 million at December 31, 2020 (carried at weighted average cost). In the third quarter of 2021, the Company and Southwest classified certain assets associated with its previous corporate headquarters as held for sale. As a result, the Company and Southwest reclassified approximately $31 million from Net utility plant to Prepaid and other current assets on their respective Condensed Consolidated Balance Sheets during the third quarter of 2021; this was a non-cash item and therefore did not impact the Company’s or Southwest’s respective Condensed Consolidated Statements of Cash Flows.
Goodwill	Goodwill. Goodwill is assessed as of October 1st each year for impairment, or more frequently, if circumstances indicate an impairment to the carrying value of goodwill may have occurred. Management of the Company and Southwest considered its reporting units and segments and determined that they remained consistent between periods presented below, and that no change was necessary with regard to the level at which goodwill is assessed for impairment.
Other current liabilities	Other Current Liabilities. Management recognizes in its balance sheets various liabilities that are expected to be settled through future cash payment within the next twelve months, including amounts payable under regulatory mechanisms, customary accrued expenses for employee compensation and benefits, declared but unpaid dividends, and miscellaneous other accrued liabilities. Other current liabilities for the Company includes $35.9 million and $32.6 million of dividends declared as of September 30, 2021 and December 31, 2020, respectively, as well as liabilities included as part of the Riggs Distler acquisition.
Earnings Per Share	Earnings Per Share. Basic earnings per share (“EPS”) in each period of this report were calculated by dividing net income attributable to Southwest Gas Holdings, Inc. by the weighted-average number of shares during those periods. Diluted EPS includes additional weighted-average common stock equivalents (performance shares and restricted stock units). Unless otherwise noted, the term “Earnings Per Share” refers to Basic EPS.
Recent Accounting Standards Updates	Recent Accounting Standards Updates. Accounting pronouncements adopted in 2021: In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” The update simplifies the accounting for income taxes by removing certain exceptions to the general principles, as well as improving consistent application in Topic 740 by clarifying and amending existing guidance. The Company and Southwest adopted the update in the first quarter of 2021, the impact of which was not material to the condensed consolidated financial statements of the Company or Southwest. Recently issued accounting pronouncements that will be effective after 2021: In March 2020, the FASB issued ASU 2020-04 “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The update provides optional guidance for a limited time to ease the potential burden in accounting for, or recognizing the effects of, reference rate reform on financial reporting, including when modifying a contract (during the eligibility period covered by the update to Topic 848) to replace a reference rate affected by such reform. The update applies only to contracts and hedging relationships that reference the London Interbank Offered Rate (“LIBOR”) or another rate expected to be discontinued due to reference rate reform. The guidance was eligible to be applied upon issuance on March 12, 2020, and can generally be applied through December 31, 2022, but to date, no further updates have occurred that would extend the optional guidance to the full tenor of LIBOR expiration dates occurring after 2022. Management will monitor the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures, and will reflect such appropriately, in the event that the optional guidance is elected. It will also monitor further FASB action, if any, in regard to the full tenor of LIBOR expiration dates. See also LIBOR discussion in Note 5 – Debt. In August 2020, the FASB issued ASU 2020-06 “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity.” The update, amongst other amendments, improves the guidance related to the disclosures and earnings-per-share for convertible instruments and contracts in an entity’s own equity. The update is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years; early adoption is permitted. Management is evaluating what impacts, if any, this update might have on the Company’s consolidated financial statements and disclosures.

Background, Organization, and Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Operations. Southwest Gas Holdings, Inc. is a holding company, owning all of the shares of common stock of Southwest Gas Corporation (“Southwest” or the “natural gas operations” segment) and all of the shares of common stock of Centuri Group, Inc. (“Centuri,” or the “utility infrastructure services” segment).

In October 2021, Southwest Gas Holdings, Inc. (the “Company”) entered into an agreement with Dominion Energy Questar Corporation, a wholly owned subsidiary of Dominion Energy, Inc., to acquire all equity interests in Dominion Energy Questar Pipeline, LLC and related entities (“Questar Pipelines”). Upon closing, Questar Pipelines will operate as part of a standalone subsidiary of the Company, and will undergo new branding at or subsequent to close. The agreement provides for consideration of $1.545 billion in cash (subject to certain adjustments) and assumption of approximately $430 million of existing long-term debt. The agreement contains certain termination rights, including a mutual termination right exercisable at any time and a unilateral termination right exercisable by either party if certain conditions have not been met by December 31, 2021 (the initial termination date), subject to an extension unilaterally exercisable by either party if certain conditions have not been met, subsequently extending the initial termination date through June 30, 2022. The completion of this transaction is subject to closing conditions, including the expiration or termination of any waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and approval of certain aspects of the transaction by the Federal Communications Commission. The operations to be acquired would further diversify the Company’s business with an expansion of regulated interstate natural gas pipelines and underground storage services as part of the jurisdiction of the Federal Energy Regulatory Commission (the “FERC”), thereby expanding transportation services into Utah, Wyoming, and Colorado. The Company plans to initially fund this acquisition with a new 364-day term loan, followed by permanent financing. See Note 5 – Debt for more information.

Southwest is engaged in the business of purchasing, distributing, and transporting natural gas for customers in portions of Arizona, Nevada, and California. Public utility rates, practices, facilities, and service territories of Southwest are subject to regulatory oversight. The timing and amount of rate relief can materially impact results of operations. Natural gas purchases and the timing of related recoveries can materially impact liquidity. Results for the natural gas operations segment are higher during winter periods due to the seasonality incorporated in its regulatory rate structures.

Centuri is a comprehensive utility infrastructure services enterprise dedicated to delivering a diverse array of solutions to North America’s gas and electric providers. Centuri derives revenue primarily from installation, replacement, repair, and maintenance of energy distribution systems. Centuri operations are generally conducted under the business names of NPL Construction Co. (“NPL”), NPL Canada Ltd. (“NPL Canada”), New England Utility Constructors, Inc. (“Neuco”), Linetec Services, LLC (“Linetec”), and Riggs Distler & Company, Inc. (“Riggs Distler”). Utility infrastructure services activity is seasonal in most of Centuri’s operating areas. Peak periods are the summer and fall months in colder climate areas, such as the northeastern and midwestern United States (“U.S.”) and in Canada. In warmer climate areas, such as the southwestern and southeastern U.S., utility infrastructure services activity continues year round.

Basis of Presentation

Basis of Presentation. The condensed consolidated financial statements of Southwest Gas Holdings, Inc. and subsidiaries and Southwest included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The year-end condensed balance sheet data was derived from audited financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. No substantive change has occurred with regard to the Company’s business segments on the whole.

The preparation of the condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of management, all adjustments, consisting of normal recurring items and estimates necessary for a fair depiction of results for the interim periods, have been made. In association with the novel Coronavirus (“COVID-19”) pandemic environment, utility operations, and to a large extent, utility infrastructure services, were deemed “essential services.” Management has considered the impact of the pandemic and adjusted certain estimates, where relevant, in the preparation of the condensed consolidated financial statements.

These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2020 Annual Report to Stockholders, which is incorporated by reference into the 2020 Form 10-K.

Fair Value Measurements

Fair Value Measurements. Certain assets and liabilities are reported at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

U.S. GAAP states that a fair value measurement should be based on the assumptions that market participants would use in pricing the asset or liability and establishes a fair value hierarchy that ranks the inputs used to measure fair value by their reliability. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to fair values derived from unobservable inputs (Level 3 measurements). Financial assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows:

Level 1 – quoted prices (unadjusted) in active markets for identical assets or liabilities that a company has the ability to access at the measurement date.

Level 2 – inputs other than quoted prices included within Level 1 that are observable for similar assets or liabilities, either directly or indirectly.

Level 3 – unobservable inputs for the asset or liability. Unobservable inputs are used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date.

The Company primarily used quoted market prices and other observable market pricing information in valuing cash and cash equivalents, long-term debt outstanding, and assets of the qualified pension plan and postretirement benefit plans required to be recorded and/or disclosed at fair value.

Cash and Cash Equivalents

Cash and Cash Equivalents. For purposes of reporting consolidated cash flows, cash and cash equivalents include cash on hand and financial instruments with original maturities of three months or less. Such investments are carried at cost, which approximates market value. Cash and cash equivalents of the Company include $55 million of money market fund investments at September 30, 2021, and an insignificant amount at December 31, 2020. The money market fund investments for Southwest were insignificant at both balance sheet dates. These investments fall within Level 2 of the fair value hierarchy, due to the asset valuation methods used by money market funds.

Typical non-cash investing activities include customer advances applied as contributions toward utility construction activity, and capital expenditures that were not yet paid as of period-end reporting dates, but rather were included in accounts payable. Typical activities that represent aspects of both non-cash investing and non-cash financing activities relate to right-of-use assets obtained in exchange for lease liabilities (including, at times, lease terminations and modifications). Amounts related to these collective activities were immaterial for the periods presented herein. See also Prepaid and other current assets below.

Intercompany Transactions

Intercompany Transactions. Centuri recognizes revenues generated from contracts with Southwest (see Note 7 – Segment Information). The accounts receivable balance, revenues, and associated profits are included in the condensed consolidated financial statements of the Company and Southwest and were not eliminated during consolidation in accordance with accounting treatment for rate-regulated entities.

Accounts Receivable, net of allowances

Accounts Receivable, net of allowances. Business activity with respect to natural gas utility operations is conducted with customers located within the three-state region of Arizona, Nevada, and California. Southwest’s accounts receivable are short-term in nature with no billing due dates customarily extending beyond one month, with customers’ credit worthiness assessed upon account creation by evaluation of other utility service and related payment history. Southwest lifted the moratorium on disconnection of natural gas service for non-payment in Arizona and Nevada in September 2021, which was initiated (at the same time as a moratorium on late fees) in March 2020 in response to the COVID-19 pandemic. The moratorium on disconnection continues to be in place for California, and is expected to be lifted in the fourth quarter of 2021. Southwest recommenced assessing late fees on past-due balances in Arizona and Nevada in April 2021, and expects to recommence late fees in California in the fourth quarter of 2021. Southwest is actively working with customers experiencing financial hardship by means of flexible payment options. Management continues to monitor expected credit losses in light of the impact of COVID-19. The allowance for uncollectible accounts receivable balances as of September 30, 2021 reflects the expected impact from the pandemic on balances as of that date, including consideration of customers’ ability to pay those amounts that are due.

Utility infrastructure services contracts receivable are recorded at face amounts less an allowance for doubtful accounts. Centuri’s customers are generally investment-grade gas and electric utility companies for which Centuri has historically recognized an insignificant amount of write-offs. Centuri has not been significantly impacted, nor does it anticipate it will experience significant difficulty in collecting amounts due, as a result of the current environment surrounding COVID-19 given the nature of its customers.

Activity between periods in the allowance for uncollectible accounts and the balances as of the periods presented within the Company’s and Southwest’s financial statements were not material to the condensed consolidated financial statements overall.

Deferred Purchased Gas Costs

Deferred Purchased Gas Costs. The various regulatory commissions have established procedures to enable Southwest to adjust its billing rates for changes in the cost of natural gas purchased. The difference between the current cost of gas purchased and the cost of gas recovered in billed rates is deferred. Generally, these deferred amounts are recovered or refunded within one year.

In mid-February 2021, the central U.S. (from south Texas to North Dakota and the eastern Rocky Mountains) experienced extreme cold temperatures, which increased natural gas demand and caused supply issues due to wellhead freeze-offs, power outages, or other adverse operating conditions upstream of Southwest’s distribution systems. These conditions caused daily natural gas prices to reach unprecedented levels. During this time, Southwest secured natural gas supplies, albeit at substantially higher prices, maintaining service to its customers. The incremental cost for these supplies was approximately $250 million, funded using a 364-day $250 million term loan executed in March 2021 (see Note 5 – Debt). The incremental gas costs are expected to continue to be collected from customers through the purchased gas adjustment (“PGA”) mechanisms.

Following the extreme weather event, an interstate transmission pipeline company billed Southwest, in addition to customary transmission costs, $65 million (later reduced to approximately $55 million) for pipeline imbalance charges, allegedly incurred during the period of the pipeline’s critical operation condition. However, Southwest formally disputed the imbalance charges, in addition to interest on that amount, believing that no amounts were due to the pipeline. In June 2021, the interstate transmission pipeline company requested approval from the Federal Energy Regulatory Commission (the “FERC”) to waive these imbalance charges and interest, affirming that they had the authority to elect the option to waive the underlying charges based on their tariff, but were seeking approval by the FERC for purposes of transparency and regulatory certainty. In August 2021, FERC approval was received. Consequently, no amounts were recognized by Southwest related to the original charge from the pipeline.

Prepaid and other current assets

Prepaid and other current assets. Prepaid and other current assets includes gas pipe materials and operating supplies of $55 million at September 30, 2021 and $50 million at December 31, 2020 (carried at weighted average cost).

In the third quarter of 2021, the Company and Southwest classified certain assets associated with its previous corporate headquarters as held for sale. As a result, the Company and Southwest reclassified approximately $31 million from Net utility plant to Prepaid and other current assets on their respective Condensed Consolidated Balance Sheets during the third quarter of 2021; this was a non-cash item and therefore did not impact the Company’s or Southwest’s respective Condensed Consolidated Statements of Cash Flows.

Goodwill

Goodwill. Goodwill is assessed as of October 1st each year for impairment, or more frequently, if circumstances indicate an impairment to the carrying value of goodwill may have occurred. Management of the Company and Southwest considered its reporting units and segments and determined that they remained consistent between periods presented below, and that no change was necessary with regard to the level at which goodwill is assessed for impairment.

Other current liabilities

Other Current Liabilities. Management recognizes in its balance sheets various liabilities that are expected to be settled through future cash payment within the next twelve months, including amounts payable under regulatory mechanisms, customary accrued expenses for employee compensation and benefits, declared but unpaid dividends, and miscellaneous other accrued liabilities. Other current liabilities for the Company includes $35.9 million and $32.6 million of dividends declared as of September 30, 2021 and December 31, 2020, respectively, as well as liabilities included as part of the Riggs Distler acquisition.

Earnings Per Share

Earnings Per Share. Basic earnings per share (“EPS”) in each period of this report were calculated by dividing net income attributable to Southwest Gas Holdings, Inc. by the weighted-average number of shares during those periods. Diluted EPS includes additional weighted-average common stock equivalents (performance shares and restricted stock units). Unless otherwise noted, the term “Earnings Per Share” refers to Basic EPS.

Recent Accounting Standards Updates

Recent Accounting Standards Updates.

Accounting pronouncements adopted in 2021:

In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” The update simplifies the accounting for income taxes by removing certain exceptions to the general principles, as well as improving consistent application in Topic 740 by clarifying and amending existing guidance. The Company and Southwest adopted the update in the first quarter of 2021, the impact of which was not material to the condensed consolidated financial statements of the Company or Southwest.

Recently issued accounting pronouncements that will be effective after 2021:

In March 2020, the FASB issued ASU 2020-04 “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The update provides optional guidance for a limited time to ease the potential burden in accounting for, or recognizing the effects of, reference rate reform on financial reporting, including when modifying a contract (during the eligibility period covered by the update to Topic 848) to replace a reference rate affected by such reform. The update applies only to contracts and hedging relationships that reference the London Interbank Offered Rate (“LIBOR”) or another rate expected to be discontinued due to reference rate reform. The guidance was eligible to be applied upon issuance on March 12, 2020, and can generally be applied through December 31, 2022, but to date, no further updates have occurred that would extend the optional guidance to the full tenor of LIBOR expiration dates occurring after 2022. Management will monitor the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures, and will reflect such appropriately, in the event that the optional guidance is elected. It will also monitor further FASB action, if any, in regard to the full tenor of LIBOR expiration dates. See also LIBOR discussion in Note 5 – Debt.

In August 2020, the FASB issued ASU 2020-06 “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity.” The update, amongst other amendments, improves the guidance related to the disclosures and earnings-per-share for convertible instruments and contracts in an entity’s own equity. The update is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years; early adoption is permitted. Management is evaluating what impacts, if any, this update might have on the Company’s consolidated financial statements and disclosures.