Background, Organization, and Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2020
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). 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 from installation, replacement, repair, and maintenance of energy distribution systems, and developing industrial construction solutions. 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”), and Linetec Services, LLC (“Linetec”). 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 (the “Company”) 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 at 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. Globally, the novel Coronavirus (“COVID-19”) pandemic has created volatility, uncertainty, and economic disruption. Utility operations have been deemed “essential services” and utility infrastructure services have, to a large extent, been similarly characterized by government officials. Management has considered the impact of the pandemic and adjusted certain estimates, where relevant, used in the preparation of the condensed consolidated financial statements. It is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and the notes thereto included in the 2019 Annual Report to Stockholders, which is incorporated by reference into the 2019 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, derivatives, 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 for Southwest and the Company also include money market fund investments totaling approximately $40,000 and $49,000, respectively, at March 31, 2020, and $23.5 million and $26.7 million, respectively, at December 31, 2019, which 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 for Southwest include customer advances applied as contributions toward utility construction activity, capital expenditures that were not paid as of period end reporting dates but rather included in accounts payable, and right-of use assets obtained in exchange for lease liabilities, which are non-cash investing and financing activities. Amounts related to such activities were immaterial for the periods presented herein.
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. On January 2, 2020, the Company adopted the Financial Accounting Standards Board’s (the “FASB”) Accounting Standards Update (“ASU”) 2016-13 “Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments,” which replaces the incurred loss methodology with an expected loss methodology that is referred to as the current expected credit loss, or CECL, methodology. The Company adopted ASU 2016-13 using the modified retrospective method, and therefore, results for reporting periods beginning prior to January 1, 2020 are presented under previously accepted U.S. GAAP. See Recent Accounting Standards Updates below. 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 payments history. Although Southwest seeks to minimize its credit risk related to utility operations by requiring security deposits from new customers, imposing late fees, and actively pursuing collection on overdue accounts, some accounts are ultimately not collected. Customer accounts are subject to collection procedures that vary by jurisdiction (late fee assessment, noticing requirements for disconnection of service, and procedures for actual disconnection and/or reestablishment of service). After disconnection of service, accounts are customarily written off approximately two months after inactivation. Dependent upon the jurisdiction, reestablishment of service requires both payment of previously unpaid balances and additional deposit requirements. Provisions for uncollectible accounts are recorded monthly based on experience, consideration of current and expected future conditions, customer and rate composition, and write-off processes. They are included in the ratemaking process as a cost of service. The Nevada jurisdictions have a regulatory mechanism associated with the gas cost-related portion of uncollectible accounts. Such amounts are deferred and collected through a surcharge in the ratemaking process. Due to the COVID-19 pandemic, and as utility service is an essential service to the residents in the states in which Southwest operates, Southwest implemented a temporary moratorium on disconnection of natural gas service for non-payment and it also ceased charging late fees until further notice. Southwest is also actively working with customers experiencing financial hardship by means of flexible payment options. Management is monitoring expected credit losses in light of the evolving financial impact of COVID-19, and has adjusted the allowance for uncollectibles as of March 31, 2020 as a result of the anticipated impact on Southwest’s customers’ ability to pay amounts due both currently and when the moratorium is lifted. The adjustment was not material to the financial statements overall, and entering the summer season, during which time monthly billing amounts are substantially reduced, management does not expect a material increase to the allowance for uncollectibles. 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’s trade accounts receivable balances carry standard payment terms of up to 60 days. Centuri maintains an allowance that is an estimate based on historical collection experience, current and forward-looking estimated economic and market conditions, and a review of the current status of each customer's trade accounts receivable balance. Account balances are monitored at least monthly, and are charged-off against the allowance when management determines it is probable the balance will not be recovered. Centuri has not been significantly impacted, nor does it anticipate it will experience significant difficulty in collecting amounts due as a result of COVID-19 given the nature of its customers. Activity in the allowance for uncollectibles and the balances as of the periods presented within the Company’s and Southwest’s financial statements are not material to the condensed consolidated financial statements.
Income Taxes	Income Taxes. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (“CARES”) Act was enacted. The CARES Act provides a number of tax provisions and stimulus measures, including changes to prior and future limitations on interest deductions, the ability to accelerate refund of Alternative Minimum Tax credits, elective deferment of payment related to the employer portion of Social Security taxes, and the creation of certain refundable employee retention credits, among other things. Management does not anticipate the impacts, if any, related to the CARES Act to have a material effect on the Company’s or Southwest’s results of operations, financial position, or liquidity.
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 its segments and reporting units remain consistent between periods presented below, and that no change was necessary with regard to the level at which goodwill is assessed for impairment.
Derivatives	Derivatives. In managing its natural gas supply portfolios, Southwest has historically entered into fixed- and variable-price contracts, which qualify as derivatives. Additionally, Southwest has utilized fixed-for-floating swap contracts (“Swaps”) to supplement its fixed-price contracts. The fixed-price contracts, firm commitments to purchase a fixed amount of gas in the future at a fixed price, qualify for the normal purchases and normal sales exception that is allowed for contracts that are probable of delivery in the normal course of business, and are exempt from fair value reporting. The variable-price contracts qualify as derivative instruments; however, because the contract prices are the prevailing prices at the future transaction dates, the contracts have no determinable fair value. The Swap contract prices are determined at the beginning of each month to reflect that month’s published first of month index price and are recorded at fair value (Level 2). Southwest does not utilize derivative financial instruments for speculative purposes, nor does it have trading operations.
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 2020: In June 2016, the FASB issued ASU 2016-13 update “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The update requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The Company and Southwest adopted the update in the first quarter of 2020, and concluded the impact was not material to the condensed consolidated financial statements of the Company or Southwest. See Accounts receivable, net of allowances above. In January 2017, the FASB issued ASU 2017-04 “Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Under the update, an entity will apply a one-step quantitative test as opposed to a two-step test as currently required, and record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The new guidance does not amend the optional qualitative assessment. The Company and Southwest adopted the update in the first quarter of 2020 and will apply the update prospectively in any future goodwill impairment tests. In August 2018, the FASB issued ASU 2018-15 “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” The update generally aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement (that is a service contract) with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software, with the exception that such costs are to be included in the same line item in the balance sheet that a prepayment of the fees associated with the arrangement would be presented. Once capitalized, the update requires the entity to expense the amount capitalized over the term of the hosting arrangement, including reasonably certain renewal periods. The Company and Southwest adopted the update in the first quarter of 2020 using the prospective transition method. There were no material implementation costs related to cloud computing arrangements for the Company and Southwest in the first quarter of 2020. Recently issued accounting pronouncements that will be effective after 2020: In August 2018, the FASB issued ASU 2018-14 “Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans.” This update removes disclosures that are no longer considered cost-beneficial, clarifies the specific requirements of disclosures, and adds disclosure requirements identified as relevant. The update applies to all employers that sponsor defined benefit pension or other postretirement plans. The update is effective for fiscal years ending after December 15, 2020. Upon adoption, the Company and Southwest will modify their disclosures to conform to the requirements of the update. In December 2019, 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 update is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption is permitted for periods for which financial statements have not yet been made available for issuance. Management is evaluating the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures. 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. The update applies only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made or entered into after December 31, 2022. Management is evaluating the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures. See also LIBOR discussion in Note 5 – Debt.

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

3 Months Ended

Mar. 31, 2020

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).

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 from installation, replacement, repair, and maintenance of energy distribution systems, and developing industrial construction solutions. 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”), and Linetec Services, LLC (“Linetec”). 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 (the “Company”) 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 at 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. Globally, the novel Coronavirus (“COVID-19”) pandemic has created volatility, uncertainty, and economic disruption. Utility operations have been deemed “essential services” and utility infrastructure services have, to a large extent, been similarly characterized by government officials. Management has considered the impact of the pandemic and adjusted certain estimates, where relevant, used in the preparation of the condensed consolidated financial statements.

It is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and the notes thereto included in the 2019 Annual Report to Stockholders, which is incorporated by reference into the 2019 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, derivatives, 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 for Southwest and the Company also include money market fund investments totaling approximately $40,000 and $49,000, respectively, at March 31, 2020, and $23.5 million and $26.7 million, respectively, at December 31, 2019, which 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 for Southwest include customer advances applied as contributions toward utility construction activity, capital expenditures that were not paid as of period end reporting dates but rather included in accounts payable, and right-of use assets obtained in exchange for lease liabilities, which are non-cash investing and financing activities. Amounts related to such activities were immaterial for the periods presented herein.

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. On January 2, 2020, the Company adopted the Financial Accounting Standards Board’s (the “FASB”) Accounting Standards Update (“ASU”) 2016-13 “Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments,” which replaces the incurred loss methodology with an expected loss methodology that is referred to as the current expected credit loss, or CECL, methodology. The Company adopted ASU 2016-13 using the modified retrospective method, and therefore, results for reporting periods beginning prior to January 1, 2020 are presented under previously accepted U.S. GAAP. See Recent Accounting Standards Updates below.

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 payments history. Although Southwest seeks to minimize its credit risk related to utility operations by requiring security deposits from new customers, imposing late fees, and actively pursuing collection on overdue accounts, some accounts are ultimately not collected. Customer accounts are subject to collection procedures that vary by jurisdiction (late fee assessment, noticing requirements for disconnection of service, and procedures for actual disconnection and/or reestablishment of service). After disconnection of service, accounts are customarily written off approximately two months after inactivation. Dependent upon the jurisdiction, reestablishment of service requires both payment of previously unpaid balances and additional deposit requirements. Provisions for uncollectible accounts are recorded monthly based on experience, consideration of current and expected future conditions, customer and rate composition, and write-off processes. They are included in the ratemaking process as a cost of service. The Nevada jurisdictions have a regulatory mechanism associated with the gas cost-related portion of uncollectible accounts. Such amounts are deferred and collected through a surcharge in the ratemaking process. Due to the

COVID-19 pandemic, and as utility service is an essential service to the residents in the states in which Southwest operates, Southwest implemented a temporary moratorium on disconnection of natural gas service for non-payment and it also ceased charging late fees until further notice. Southwest is also actively working with customers experiencing financial hardship by means of flexible payment options. Management is monitoring expected credit losses in light of the evolving financial impact of COVID-19, and has adjusted the allowance for uncollectibles as of March 31, 2020 as a result of the anticipated impact on Southwest’s customers’ ability to pay amounts due both currently and when the moratorium is lifted. The adjustment was not material to the financial statements overall, and entering the summer season, during which time monthly billing amounts are substantially reduced, management does not expect a material increase to the allowance for uncollectibles.

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’s trade accounts receivable balances carry standard payment terms of up to 60 days. Centuri maintains an allowance that is an estimate based on historical collection experience, current and forward-looking estimated economic and market conditions, and a review of the current status of each customer's trade accounts receivable balance. Account balances are monitored at least monthly, and are charged-off against the allowance when management determines it is probable the balance will not be recovered. Centuri has not been significantly impacted, nor does it anticipate it will experience significant difficulty in collecting amounts due as a result of COVID-19 given the nature of its customers.

Activity in the allowance for uncollectibles and the balances as of the periods presented within the Company’s and Southwest’s financial statements are not material to the condensed consolidated financial statements.

Income Taxes

Income Taxes. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (“CARES”) Act was enacted. The CARES Act provides a number of tax provisions and stimulus measures, including changes to prior and future limitations on interest deductions, the ability to accelerate refund of Alternative Minimum Tax credits, elective deferment of payment related to the employer portion of Social Security taxes, and the creation of certain refundable employee retention credits, among other things. Management does not anticipate the impacts, if any, related to the CARES Act to have a material effect on the Company’s or Southwest’s results of operations, financial position, or liquidity.

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 its segments and reporting units remain consistent between periods presented below, and that no change was necessary with regard to the level at which goodwill is assessed for impairment.

Derivatives

Derivatives. In managing its natural gas supply portfolios, Southwest has historically entered into fixed- and variable-price contracts, which qualify as derivatives. Additionally, Southwest has utilized fixed-for-floating swap contracts (“Swaps”) to supplement its fixed-price contracts. The fixed-price contracts, firm commitments to purchase a fixed amount of gas in the future at a fixed price, qualify for the normal purchases and normal sales exception that is allowed for contracts that are probable of delivery in the normal course of business, and are exempt from fair value reporting. The variable-price contracts qualify as derivative instruments; however, because the contract prices are the prevailing prices at the future transaction dates, the contracts have no determinable fair value. The Swap contract prices are determined at the beginning of each month to reflect that month’s published first of month index price and are recorded at fair value (Level 2). Southwest does not utilize derivative financial instruments for speculative purposes, nor does it have trading operations.

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 2020:

In June 2016, the FASB issued ASU 2016-13 update “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The update requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The Company and Southwest adopted the update in the first quarter of 2020, and concluded the impact was not material to the condensed consolidated financial statements of the Company or Southwest. See Accounts receivable, net of allowances above.

In January 2017, the FASB issued ASU 2017-04 “Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Under the update, an entity will apply a one-step quantitative test as opposed to a two-step test as currently required, and record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The new guidance does not amend the optional qualitative assessment. The Company and Southwest adopted the update in the first quarter of 2020 and will apply the update prospectively in any future goodwill impairment tests.

In August 2018, the FASB issued ASU 2018-15 “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” The update generally aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement (that is a service contract) with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software, with the exception that such costs are to be included in the same line item in the balance sheet that a prepayment of the fees associated with the arrangement would be presented. Once capitalized, the update requires the entity to expense the amount capitalized over the term of the hosting arrangement, including reasonably certain renewal periods. The Company and Southwest adopted the update in the first quarter of 2020 using the prospective transition method. There were no material implementation costs related to cloud computing arrangements for the Company and Southwest in the first quarter of 2020.

Recently issued accounting pronouncements that will be effective after 2020:

In August 2018, the FASB issued ASU 2018-14 “Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans.” This update removes disclosures that are no longer considered cost-beneficial, clarifies the specific requirements of disclosures, and adds disclosure requirements identified as relevant. The update applies to all employers that sponsor defined benefit pension or other postretirement plans. The update is effective for fiscal years ending after December 15, 2020. Upon adoption, the Company and Southwest will modify their disclosures to conform to the requirements of the update.

In December 2019, 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 update is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption is permitted for periods for which financial statements have not yet been made available for issuance. Management is evaluating the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures.

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. The update applies only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made or entered into after December 31, 2022. Management is evaluating the impacts this update might have on the Company’s and Southwest’s consolidated financial statements and disclosures. See also LIBOR discussion in Note 5 – Debt.