CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash Flows From Operating Activities
Net income	$ 837,434	$ 743,315
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	363,283	329,695
Deferred income taxes	170,965	110,098
Other	(32,691)	(28,023)
Net assets / liabilities from risk management activities	845	1,683
Net change in other operating assets and liabilities	(134,877)	(164,895)
Net cash provided by operating activities	1,204,959	991,873
Cash Flows From Investing Activities
Capital expenditures	(1,730,857)	(1,415,526)
Debt and equity securities activities, net	710	(1,010)
Other, net	12,609	7,272
Net cash used in investing activities	(1,717,538)	(1,409,264)
Cash Flows From Financing Activities
Net decrease in short-term debt	0	(241,933)
Net proceeds from equity issuances	379,490	254,022
Issuance of common stock through stock purchase and employee retirement plans	7,888	7,771
Proceeds from issuance of long-term debt	645,372	898,275
Repayment of securitized long-term debt by AEK	(4,051)	(5,738)
Cash dividends paid	(273,869)	(241,565)
Debt issuance costs	(5,987)	(8,920)
Net cash provided by financing activities	748,843	661,912
Net increase in cash and cash equivalents and restricted cash and cash equivalents	236,264	244,521
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	308,856	19,248
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 545,120	$ 263,769