CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common stock shares	Additional paid-in capital	Accumulated other comprehensive loss	Retained earnings	Southwest Gas Holdings, Inc.
Beginning balance (in shares) at Dec. 31, 2022		67,119,000
Beginning balance at Dec. 31, 2022		$ 68,749	$ 2,287,183	$ (44,242)	$ 747,069
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuances (in shares)		4,212,000
Common stock issuances		$ 4,212	237,448
Promissory notes in association with redeemable noncontrolling interest			0
Foreign currency exchange translation adjustment				97
Net actuarial gain arising during period, less amortization of unamortized benefit plan cost, net of tax				196
Net income					45,911
Dividends declared					(44,635)
Redemption value adjustments					(5,832)
Ending balance (in shares) at Mar. 31, 2023		71,331,000
Ending balance at Mar. 31, 2023		$ 72,961	2,524,631	(43,949)	742,513	$ 3,296,156
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in USD per share)	$ 0.62
Beginning balance (in shares) at Dec. 31, 2023	71,563,750	71,564,000
Beginning balance at Dec. 31, 2023		$ 73,194	2,541,790	(43,787)	738,839
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuances (in shares)		101,000
Common stock issuances		$ 101	1,508
Promissory notes in association with redeemable noncontrolling interest			4,187
Foreign currency exchange translation adjustment				(2,819)
Net actuarial gain arising during period, less amortization of unamortized benefit plan cost, net of tax				384
Net income					87,737
Dividends declared					(44,699)
Redemption value adjustments	$ 194				(194)
Ending balance (in shares) at Mar. 31, 2024	71,665,592	71,665,000
Ending balance at Mar. 31, 2024		$ 73,295	$ 2,547,485	$ (46,222)	$ 781,683	$ 3,356,241
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per common share (in USD per share)	$ 0.62