Background, Organization, and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations. Southwest Gas Holdings, Inc. (together with its subsidiaries, the “Company”) is a holding company, owning all of the shares of common stock of Southwest Gas Corporation (“Southwest” or the “natural gas distribution” segment), all of the shares of common stock of Centuri Group, Inc. (“Centuri,” or the “utility infrastructure services” segment), and all of the shares of common stock of MountainWest Pipelines Holding Company (“MountainWest,” or the “pipeline and storage” segment). 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 distribution segment are higher during winter periods due to the seasonality incorporated in its regulatory rate structures. The Company completed the acquisition of Dominion Energy Questar Pipeline, LLC and related entities (“Questar Pipelines”) in December 2021 and formed MountainWest, which owns all of the membership interests in Questar Pipelines. In April 2022, the Company completed a general rebranding of the Questar Pipelines entities under the MountainWest name. The acquired operations further diversify the Company’s business in the midstream sector, with an expansion of interstate natural gas pipelines and underground storage services, primarily composed of regulated operations under the jurisdiction of the Federal Energy Regulatory Commission (the “FERC”), thereby expanding natural gas transportation services into Utah, Wyoming, and Colorado. See Note 8 - Business Acquisitions for more information. Centuri is a strategic utility infrastructure services company dedicated to partnering with North America’s gas and electric providers to build and maintain the energy network that powers millions of homes across the United States (“U.S.”) and Canada. Centuri derives revenue primarily from installation, replacement, repair, and maintenance of energy networks. Centuri operates in the U.S., primarily as NPL, Neuco, Linetec, and Riggs Distler, and in Canada, primarily as NPL Canada. Utility infrastructure services activity is seasonal in many of Centuri’s operating areas. Peak periods are the summer and fall months in colder climate areas, such as the northeastern and midwestern 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 (with its subsidiaries) included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The year-end 2021 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 during the recently completed quarter. 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. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2021 Annual Report to Stockholders, which is incorporated by reference into the 2021 Form 10-K.
Cash and Cash Equivalents	Cash and Cash Equivalents. Cash and cash equivalents of the Company include $56 million and $20 million of money market fund investments at September 30, 2022 and December 31, 2021, respectively. 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. Noncash investing activities for the Company and Southwest include capital expenditures that were not yet paid, thereby remaining in accounts payable, the amounts related to which declined by approximately $4.8 million and $11.6 million during the nine months ended September 30, 2022, respectively, and increased $16.1 million and $9.4 million during the twelve months ended September 30, 2022, respectively.
Accounts Receivable, net of allowances	Accounts Receivable, net of allowances. Following an earlier moratorium on account disconnections amidst the COVID-19 environment, account collection efforts resumed in 2021 in all jurisdictions in which Southwest operates. Ultimately, some accounts may not be collected, and if collection is unsuccessful, such accounts are written off. Estimates as to collectibility are made on an ongoing basis. However, Southwest continues to actively work with customers experiencing financial hardship by means of flexible payment options and partnering with assistance agencies. The cost of gas included in customer rates also influences account balances at each reporting date.
Deferred Purchased Gas Costs	Deferred Purchased Gas Costs. The various regulatory commissions have established procedures to enable the rate-regulated companies to adjust 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.
Prepaid and other current assets	Prepaid and other current assets. Prepaid and other current assets for Southwest include, among other things, materials and operating supplies of $76.5 million at September 30, 2022 and $62.9 million at December 31, 2021 (carried at weighted average cost). For the Company, there were materials and operating supplies of $80.8 million and $67.4 million at September 30, 2022 and December 31, 2021, respectively, which included amounts for MountainWest. Also included in the balance for both Southwest and the Company was $15.5 million and $51.6 million as of September 30, 2022 and December 31, 2021, respectively, in accrued purchased gas cost.
Goodwill	Goodwill. Goodwill is assessed as of October 1st each year for impairment, or more frequently, if circumstances indicate it may be more likely than not that the fair value of a reporting unit is less than its carrying value. The Company’s reporting units for goodwill are its operating segments, which are also its reportable segments. The acquisition of MountainWest resulted in a new reportable segment, which was assessed for impairment for the first time in 2022.
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 include $41.6 million and $36 million of dividends declared as of September 30, 2022 and December 31, 2021, respectively.
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 effective or adopted in 2022: In March 2020, the Financial Accounting Standards Board (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, and while a proposal by the FASB has occurred to extend the optional guidance to the full tenor of LIBOR expiration dates occurring after 2022, to date, no such update has been made effective. 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. Management will also monitor further FASB action, if any, in regard to the full tenor of LIBOR expiration dates. 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 Company and Southwest adopted the update in the first quarter of 2022, the impact of which was not material to the consolidated financial statements of the Company or Southwest.

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

9 Months Ended

Sep. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Operations. Southwest Gas Holdings, Inc. (together with its subsidiaries, the “Company”) is a holding company, owning all of the shares of common stock of Southwest Gas Corporation (“Southwest” or the “natural gas distribution” segment), all of the shares of common stock of Centuri Group, Inc. (“Centuri,” or the “utility infrastructure services” segment), and all of the shares of common stock of MountainWest Pipelines Holding Company (“MountainWest,” or the “pipeline and storage” segment).

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 distribution segment are higher during winter periods due to the seasonality incorporated in its regulatory rate structures.

The Company completed the acquisition of Dominion Energy Questar Pipeline, LLC and related entities (“Questar Pipelines”) in December 2021 and formed MountainWest, which owns all of the membership interests in Questar Pipelines. In April 2022, the Company completed a general rebranding of the Questar Pipelines entities under the MountainWest name. The acquired operations further diversify the Company’s business in the midstream sector, with an expansion of interstate natural gas pipelines and underground storage services, primarily composed of regulated operations under the jurisdiction of the Federal Energy Regulatory Commission (the “FERC”), thereby expanding natural gas transportation services into Utah, Wyoming, and Colorado. See Note 8 - Business Acquisitions for more information.

Centuri is a strategic utility infrastructure services company dedicated to partnering with North America’s gas and electric providers to build and maintain the energy network that powers millions of homes across the United States (“U.S.”) and Canada. Centuri derives revenue primarily from installation, replacement, repair, and maintenance of energy networks. Centuri operates in the U.S., primarily as NPL, Neuco, Linetec, and Riggs Distler, and in Canada, primarily as NPL Canada. Utility infrastructure services activity is seasonal in many of Centuri’s operating areas. Peak periods are the summer and fall months in colder climate areas, such as the northeastern and midwestern 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 (with its subsidiaries) included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The year-end 2021 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 during the recently completed quarter.

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.

These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2021 Annual Report to Stockholders, which is incorporated by reference into the 2021 Form 10-K.

Cash and Cash Equivalents

Cash and Cash Equivalents. Cash and cash equivalents of the Company include $56 million and $20 million of money market fund investments at September 30, 2022 and December 31, 2021, respectively. 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.

Noncash investing activities for the Company and Southwest include capital expenditures that were not yet paid, thereby remaining in accounts payable, the amounts related to which declined by approximately $4.8 million and $11.6 million during the nine months ended September 30, 2022, respectively, and increased $16.1 million and $9.4 million during the twelve months ended September 30, 2022, respectively.

Accounts Receivable, net of allowances

Accounts Receivable, net of allowances. Following an earlier moratorium on account disconnections amidst the COVID-19 environment, account collection efforts resumed in 2021 in all jurisdictions in which Southwest operates. Ultimately, some accounts may not be collected, and if collection is unsuccessful, such accounts are written off. Estimates as to collectibility are made on an ongoing basis. However, Southwest continues to actively work with customers experiencing financial hardship by means of flexible payment options and partnering with assistance agencies. The cost of gas included in customer rates also influences account balances at each reporting date.

Deferred Purchased Gas Costs

Deferred Purchased Gas Costs. The various regulatory commissions have established procedures to enable the rate-regulated companies to adjust 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.

Prepaid and other current assets

Prepaid and other current assets. Prepaid and other current assets for Southwest include, among other things, materials and operating supplies of $76.5 million at September 30, 2022 and $62.9 million at December 31, 2021 (carried at weighted average cost). For the Company, there were materials and operating supplies of $80.8 million and $67.4 million at September 30, 2022 and December 31, 2021, respectively, which included amounts for MountainWest. Also included in the balance for both Southwest and the Company was $15.5 million and $51.6 million as of September 30, 2022 and December 31, 2021, respectively, in accrued purchased gas cost.

Goodwill

Goodwill. Goodwill is assessed as of October 1st each year for impairment, or more frequently, if circumstances indicate it may be more likely than not that the fair value of a reporting unit is less than its carrying value. The Company’s reporting units for goodwill are its operating segments, which are also its reportable segments. The acquisition of MountainWest resulted in a new reportable segment, which was assessed for impairment for the first time in 2022.

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 include $41.6 million and $36 million of dividends declared as of September 30, 2022 and December 31, 2021, respectively.

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 effective or adopted in 2022:

In March 2020, the Financial Accounting Standards Board (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, and while a proposal by the FASB has occurred to extend the optional guidance to the full tenor of LIBOR expiration dates occurring after 2022, to date, no such update has been made effective. 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. Management will also monitor further FASB action, if any, in regard to the full tenor of LIBOR expiration dates. 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 Company and Southwest adopted the update in the first quarter of 2022, the impact of which was not material to the consolidated financial statements of the Company or Southwest.