CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
CASH FLOW FROM OPERATING ACTIVITIES:
Net income	$ 136,025	$ 133,949	$ 241,061	$ 225,855
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	267,670	245,009	354,688	324,995
Deferred income taxes	45,374	37,752	58,339	45,815
Changes in current assets and liabilities:
Accounts receivable, net of allowances	(62,081)	(42,139)	(68,714)	(76,769)
Accrued utility revenue	42,700	42,600	(3,200)	(700)
Deferred purchased gas costs	(293,410)	59,899	(317,070)	38,016
Accounts payable	(51,086)	(59,031)	251	(14,817)
Accrued taxes	5,954	17,991	3,134	26,075
Other current assets and liabilities	23,289	121,185	9,531	121,274
Gains on sale of equipment	(5,365)	(581)	(6,632)	(2,897)
Changes in undistributed stock compensation	7,676	5,789	9,001	6,618
Equity AFUDC	0	(3,413)	(1,311)	(4,395)
Changes in deferred charges and other assets	(7,956)	(19,174)	(21,373)	(24,370)
Changes in other liabilities and deferred credits	(57,269)	(52,018)	(67,922)	(54,996)
Net cash provided by operating activities	51,521	487,818	189,783	609,704
CASH FLOW FROM INVESTING ACTIVITIES:
Construction expenditures and property additions	(506,737)	(632,474)	(699,368)	(851,236)
Acquisition of businesses, net of cash acquired	(830,395)	(250)	(830,145)	(28,355)
Changes in customer advances	7,940	7,691	14,282	11,643
Other	14,755	6,520	17,238	8,811
Net cash used in investing activities	(1,314,437)	(618,513)	(1,497,993)	(859,137)
CASH FLOW FROM FINANCING ACTIVITIES:
Issuance of common stock, net	210,812	90,635	259,422	119,240
Dividends paid	(102,292)	(93,317)	(134,479)	(123,099)
Issuance of long-term debt, net	1,654,960	650,619	1,666,718	699,601
Retirement of long-term debt	(406,815)	(289,295)	(473,926)	(375,909)
Change in credit facility and commercial paper	(150,000)	(92,000)	(58,000)	(92,000)
Change in short-term debt	165,000	(157,000)	218,000	24,000
Withholding remittance - share-based compensation	(1,254)	(2,736)	(1,254)	(2,736)
Other	(4,355)	(1,596)	(6,161)	(4,090)
Net cash provided by financing activities	1,366,056	105,310	1,470,320	245,007
Effects of currency translation on cash and cash equivalents	198	(209)	635	(109)
Change in cash and cash equivalents	103,338	(25,594)	162,745	(4,535)
Cash and cash equivalents at beginning of period	83,352	49,539	23,945	28,480
Cash and cash equivalents at end of period	186,690	23,945	186,690	23,945
SUPPLEMENTAL INFORMATION:
Interest paid, net of amounts capitalized	57,128	63,743	98,567	103,836
Income taxes paid (received), net	7,665	(16,006)	12,720	(13,625)
Southwest Gas Corporation
CASH FLOW FROM OPERATING ACTIVITIES:
Net income	102,584	79,568	182,134	155,993
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	187,688	173,865	249,118	230,158
Deferred income taxes	35,800	25,633	55,164	23,415
Changes in current assets and liabilities:
Accounts receivable, net of allowances	43,430	70,129	(22,766)	(7,135)
Accrued utility revenue	42,700	42,600	(3,200)	(700)
Deferred purchased gas costs	(293,410)	59,899	(317,070)	38,016
Accounts payable	(42,536)	(50,314)	17,396	(476)
Accrued taxes	5,396	15,914	(12,045)	29,228
Other current assets and liabilities	18,608	74,892	(7,739)	76,194
Changes in undistributed stock compensation	5,437	4,492	6,239	4,928
Equity AFUDC	0	(3,413)	(1,311)	(4,395)
Changes in deferred charges and other assets	(18,726)	(27,688)	(35,329)	(38,357)
Changes in other liabilities and deferred credits	(55,905)	(52,532)	(68,509)	(55,536)
Net cash provided by operating activities	31,066	413,045	42,082	451,333
CASH FLOW FROM INVESTING ACTIVITIES:
Construction expenditures and property additions	(415,398)	(525,221)	(582,393)	(716,564)
Changes in customer advances	7,940	7,691	14,282	11,643
Other	65	183	653	139
Net cash used in investing activities	(407,393)	(517,347)	(567,458)	(704,782)
CASH FLOW FROM FINANCING ACTIVITIES:
Contributions from parent	202,583	131,961	248,544	165,711
Dividends paid	(82,000)	(77,500)	(109,000)	(102,400)
Issuance of long-term debt, net	297,318	446,508	297,318	446,508
Retirement of long-term debt	0	(125,000)	0	(125,000)
Change in credit facility and commercial paper	(150,000)	(92,000)	(58,000)	(92,000)
Change in short-term debt	193,000	(194,000)	250,000	(30,000)
Withholding remittance - share-based compensation	(1,254)	(2,736)	(1,254)	(2,737)
Other	(1,632)	(1,186)	(1,708)	(1,210)
Net cash provided by financing activities	458,015	86,047	625,900	258,872
Change in cash and cash equivalents	81,688	(18,255)	100,524	5,423
Cash and cash equivalents at beginning of period	41,070	40,489	22,234	16,811
Cash and cash equivalents at end of period	122,758	22,234	122,758	22,234
SUPPLEMENTAL INFORMATION:
Interest paid, net of amounts capitalized	53,220	57,168	92,778	94,106
Income taxes paid (received), net	$ 0	$ (22,962)	$ 3,359	$ (22,262)