CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 274,922	$ 117,890	$ 163,007
Adjustments to reconcile net income to cash flows from operating activities
Unrealized (gain) loss on derivative instruments	(59,906)	54,203	(9,644)
Impairment of equity method investment	0	92,000	0
Depreciation and amortization	129,249	111,387	107,368
Amortization of acquired wholesale energy contracts	2,561	4,604	4,924
Allowance for equity used during construction	(11,243)	(20,303)	(17,053)
Allowance for doubtful accounts	2,401	18,986	2,238
Non-cash lease expense	4,850	3,920	3,851
Deferred income taxes	81,659	23,796	34,346
Equivalent value of ITCs recognized on equipment financing	(7,542)	(6,482)	(6,482)
Manufactured gas plant remediation costs	(17,538)	(17,532)	(7,651)
Equity in earnings, net of distributions received from equity investees	0	(3,046)	(5,848)
Cost of removal - asset retirement obligations	(1,289)	(1,129)	(245)
Contributions to postemployment benefit plans	(6,785)	(7,669)	(9,032)
Taxes related to stock-based compensation	(144)	(159)	647
Changes in:
Components of working capital	(77,687)	10,254	(8,096)
Other noncurrent assets	(38,424)	13,715	(44,129)
Other noncurrent liabilities	48,396	(3,481)	5,280
Cash flows from operating activities	323,480	390,954	213,481
Expenditures for:
Cost of removal	(39,293)	(50,316)	(22,059)
Acquisition of assets, net of cash acquired of $5.1 million	0	0	(523,647)
Distribution from equity investees in excess of equity in earnings	2,336	3,183	1,907
Investments in equity investees, net of return of capital	5,479
Investments in equity investees, net of return of capital		(690)	(2,117)
Cash flows used in investing activities	(590,613)	(622,117)	(994,025)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	360,000	0	660,000
Payments of long-term debt	(68,343)	(18,007)	(20,286)
Proceeds from term loan	150,000	0	350,000
Payments of term loan	0	0	(350,000)
(Payments of) proceeds from short-term debt, net	(103,350)	251,950	99,900
Proceeds from sale leaseback transactions - solar	24,071	17,673	42,927
Proceeds from sale leaseback transactions - natural gas meters	17,300	0	4,000
Payments of common stock dividends	(127,704)	(116,960)	(117,804)
Proceeds from equity offering	0	0	212,900
Cash settlement of equity forward agreement	0	(2,823)	0
Proceeds from issuance of common stock - DRP	14,745	15,105	18,080
Purchases of treasury stock	0	(27,217)	0
Tax withholding payments related to net settled stock compensation	(4,177)	(1,938)	(3,813)
Cash flows from financing activities	262,542	117,783	895,904
Change in cash, cash equivalents and restricted cash	(4,591)	(113,380)	115,360
Cash, cash equivalents and restricted cash at beginning of period	6,043	119,423	4,063
Cash, cash equivalents and restricted cash at end of period	1,452	6,043	119,423
CHANGES IN COMPONENTS OF WORKING CAPITAL
Receivables	(16,658)	(81,366)	5,065
Inventories	(80,801)	(25,257)	(3,254)
Recovery of natural gas costs	1,037	(13,124)	17,479
Natural gas purchases payable	66,352	72,752	(41,326)
Natural gas purchases payable - related parties	(10)	70	1
Deferred revenue	33,802	(1,763)	1,922
Accounts payable and other	(34,259)	31,826	18,468
Prepaid expenses	(406)	(1,527)	2,548
Prepaid and accrued taxes	(1,516)	(3,449)	(2,376)
Restricted broker margin accounts	(51,165)	28,013	(6,097)
Customers’ credit balances and deposits	660	6,652	(1,182)
Other current assets (liabilities)	5,277	(2,573)	656
Total	(77,687)	10,254	(8,096)
Cash paid for:
Interest (net of amounts capitalized)	84,375	78,650	66,146
Income taxes	4,252	6,381	7,594
Accrued capital expenditures	34,674	64,626	19,434
Utility plant
Expenditures for:
Payments to acquire PP&E	(259,081)	(376,312)	(290,040)
Solar equipment
Expenditures for:
Payments to acquire PP&E	(146,676)	(87,852)	(133,841)
Storage and Transportation and other
Expenditures for:
Payments to acquire PP&E	$ (153,378)	$ (110,130)	$ (24,228)