CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash Flows From Operating Activities
Net income	$ 702,755	$ 616,843
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization expense	395,461	353,269
Deferred income taxes	40,899	144,195
Other	(15,941)	378
Net assets / liabilities from risk management activities	(7,167)	(99)
Net change in Winter Storm Uri long-term regulatory asset (See Note 8)	0	(2,088,536)
Net change in other operating assets and liabilities	(186,691)	(184,517)
Net cash provided by (used in) operating activities	929,316	(1,158,467)
Cash Flows From Investing Activities
Capital expenditures	(1,726,039)	(1,357,960)
Debt and equity securities activities, net	3,594	(2,363)
Other, net	7,876	8,006
Net cash used in investing activities	(1,714,569)	(1,352,317)
Cash Flows From Financing Activities
Net proceeds from equity issuances	675,320	460,678
Issuance of common stock through stock purchase and employee retirement plans	11,670	12,121
Proceeds from issuance of long-term debt	798,802	2,797,346
Repayment of long-term debt	(200,000)	0
Cash dividends paid	(279,256)	(241,260)
Debt issuance costs	(8,196)	(14,288)
Other	(1,735)	0
Net cash provided by financing activities	996,605	3,014,597
Net increase in cash and cash equivalents	211,352	503,813
Cash and cash equivalents at beginning of period	116,723	20,808
Cash and cash equivalents at end of period	$ 328,075	$ 524,621