CONDENSED CONSOLIDATED STATEMENTS OF INCOME - Southwest - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Regulated operations revenues	$ 743,532	$ 521,932	$ 1,743,390	$ 1,369,690
Operating expenses:
Net cost of gas sold	298,918	156,021	573,804	338,037
Operations and maintenance	149,303	106,690	515,759	411,025
Depreciation and amortization	122,646	93,442	400,245	337,816
Taxes other than income taxes	24,816	20,687	84,472	67,769
Total operating expenses	1,098,915	712,454	3,697,365	2,900,376
Operating income	168,494	173,453	364,588	448,084
Other income and (expenses):
Net interest deductions	(48,363)	(23,964)	(143,597)	(107,061)
Other income (deductions)	1,244	448	(2,703)	14,429
Total other income and (expenses)	(47,119)	(23,516)	(146,300)	(92,632)
Income before income taxes	121,375	149,937	218,288	355,452
Income tax expense	24,125	31,092	32,681	70,627
Net income attributable to Southwest Gas Holdings, Inc.	96,178	117,293	179,664	277,075
Southwest Gas Corporation
Regulated operations revenues	676,539	521,932	1,676,397	1,369,690
Operating expenses:
Net cost of gas sold	297,121	156,021	572,007	338,037
Operations and maintenance	119,636	106,135	452,051	409,429
Depreciation and amortization	72,114	68,698	256,814	239,268
Taxes other than income taxes	21,652	20,687	81,308	67,769
Total operating expenses	510,523	351,541	1,362,180	1,054,503
Operating income	166,016	170,391	314,217	315,187
Other income and (expenses):
Net interest deductions	(26,610)	(22,166)	(102,004)	(98,256)
Other income (deductions)	1,315	550	(3,794)	14,496
Total other income and (expenses)	(25,295)	(21,616)	(105,798)	(83,760)
Income before income taxes	140,721	148,775	208,419	231,427
Income tax expense	28,926	30,060	28,204	37,193
Net income attributable to Southwest Gas Holdings, Inc.	$ 111,795	$ 118,715	$ 180,215	$ 194,234