CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	[1]	$ 159,821	$ 263,965
Adjustments to reconcile net income to cash flows from operating activities
Unrealized (gain) loss on derivative instruments		(707)	23,246
Realized and unrealized gains on investments in equity securities		(1,567)	(5,332)
Gain on sale of businesses		(645)	(3,722)
Depreciation and amortization		44,143	44,314
Amortization of acquired wholesale energy contracts		7,346	17,911
Allowance for equity used during construction		(3,602)	(2,051)
Allowance for doubtful accounts		1,149	994
Deferred income taxes		16,337	28,169
Deferred income tax benefit due to the Tax Act		0	(58,532)
Manufactured gas plant remediation costs		(4,353)	(7,219)
Equity in earnings, net of distributions received from equity investees		(1,836)	(272)
Cost of removal - asset retirement obligations		(130)	(334)
Contributions to postemployment benefit plans		(1,909)	(1,648)
Tax benefit from stock-based compensation		1,284	2,841
Changes in:
Components of working capital		(71,746)	(27,122)
Other noncurrent assets		13,483	38,462
Other noncurrent liabilities		14,719	(1,199)
Cash flows from operating activities		171,787	312,471
Expenditures for:
Utility plant		(121,962)	(69,695)
Solar equipment		(52,520)	(58,992)
Midstream and other		(5,786)	(3,159)
Cost of removal		(17,134)	(33,092)
Distribution from equity investees in excess of equity in earnings		1,154	1,315
Investments in equity investees		(1,457)	(11,177)
Cash paid related to acquisition		0	(10,000)
Proceeds from sale of businesses, net of closing costs		205,745	9,399
Proceeds from sale of investments in equity securities, net		34,484	6,616
Cash flows from (used in) investing activities		42,524	(168,785)
CASH FLOWS USED IN FINANCING ACTIVITIES
Payments of long-term debt		(12,005)	(5,346)
Payments of short-term debt, net		(106,050)	(115,100)
Proceeds from sale-leaseback transaction		9,895	7,820
Payments of common stock dividends		(51,750)	(47,459)
Proceeds from waiver discount issuance of common stock		24,539	22,690
Proceeds from issuance of common stock		9,522	9,876
Tax withholding payments related to net settled stock compensation		(6,607)	(13,420)
Cash flows used in financing activities		(132,456)	(140,939)
Change in cash, cash equivalents and restricted cash		81,855	2,747
Cash, cash equivalents and restricted cash at beginning of period		1,710	2,469
Cash, cash equivalents and restricted cash at end of period		83,565	5,216
CHANGES IN COMPONENTS OF WORKING CAPITAL
Receivables		(105,900)	(151,220)
Inventories		125,810	128,895
Recovery of gas costs		(14,989)	20,260
Gas purchases payable		(21,544)	18,928
Prepaid and accrued taxes		(4,555)	15,879
Accounts payable and other		(35,953)	(17,541)
Restricted broker margin accounts		(2,217)	(29,164)
Customers' credit balances and deposits		(9,163)	(8,696)
Other current assets		(3,235)	(4,463)
Components of working capital		(71,746)	(27,122)
Cash paid for:
Interest (net of amounts capitalized)		27,454	23,765
Income taxes		1,003	2,985
Accrued capital expenditures		29,685	14,485
Inception gain on natural gas swap contract recognized as non-cash proceeds from sale of business		$ 0	$ 14,579

[1] Includes income tax benefit related to the Tax Act of $967,000 and $58.5 million, for the three and six months ended March 31, 2018, respectively.