Business Acquisitions - Schedule of Actual Results from Operations for Acquiree (Details) - Drum Parent, Inc. $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Business Acquisition [Line Items]
Utility infrastructure services revenues	$ 49,520
Net income attributable to Southwest Gas Holdings, Inc.	$ 1,646

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

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