CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
OPERATING REVENUES
Utility	$ 297,220	$ 301,420	$ 516,843	$ 501,385
Nonutility	342,394	564,835	737,807	1,176,637
Total operating revenues	639,614	866,255	1,254,650	1,678,022
Gas purchases:
Gas purchases - Related parties	1,506	2,144	3,030	4,329
Operation and maintenance	66,832	66,023	130,177	129,366
Regulatory rider expenses	15,330	15,391	27,072	28,023
Depreciation and amortization	30,784	22,311	58,542	44,143
Total operating expenses	544,399	789,254	1,057,938	1,512,278
OPERATING INCOME	95,215	77,001	196,712	165,744
Other income, net	7,261	2,758	7,547	3,627
Interest expense, net of capitalized interest	19,203	12,509	35,273	25,995
INCOME BEFORE INCOME TAXES AND EQUITY IN EARNINGS OF AFFILIATES	83,273	67,250	168,986	143,376
Income tax benefit	(1,643)	(2,952)	(1,902)	(9,913)
Equity in earnings of affiliates	3,589	3,371	6,978	6,532
NET INCOME	$ 88,505	$ 73,573	$ 177,866	$ 159,821
EARNINGS PER COMMON SHARE
Basic (usd per share)	$ 0.93	$ 0.83	$ 1.90	$ 1.80
Diluted (usd per share)	$ 0.92	$ 0.82	$ 1.89	$ 1.79
WEIGHTED AVERAGE SHARES OUTSTANDING
Basic (in shares)	95,584	88,836	93,747	88,692
Diluted (in shares)	95,890	89,228	94,073	89,093
Regulated
Gas purchases:
Gas purchases - Utility and Nonutility	$ 111,563	$ 138,117	$ 203,377	$ 225,766
Unregulated
Gas purchases:
Gas purchases - Utility and Nonutility	$ 318,384	$ 545,268	$ 635,740	$ 1,080,651