CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows From Operating Activities
Net income	$ 372,534	$ 493,124
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	192,837	177,755
Deferred income taxes	96,885	116,023
One-time income tax benefit	0	(165,675)
Other	5,334	12,252
Net assets / liabilities from risk management activities	(333)	812
Net change in operating assets and liabilities	(106,428)	117,076
Net cash provided by operating activities	560,829	751,367
Cash Flows From Investing Activities
Capital expenditures	(777,586)	(693,978)
Proceeds from the sale of discontinued operations	4,000	3,000
Debt and equity securities activities, net	777	(1,175)
Other, net	4,388	4,009
Net cash used in investing activities	(768,421)	(688,144)
Cash Flows From Financing Activities
Net decrease in short-term debt	(575,780)	(318,143)
Net proceeds from equity offering	494,085	395,092
Issuance of common stock through stock purchase and employee retirement plans	10,344	11,902
Proceeds from issuance of long-term debt	1,045,221	0
Settlements of interest rate swap	90,141	0
Repayments of Long-term Debt	450,000	0
Cash dividends paid	(120,328)	(105,891)
Debt issuance costs	(11,227)	0
Other	0	(1,518)
Net cash provided by (used in) financing activities	302,174	(18,558)
Net increase in cash and cash equivalents	94,582	44,665
Cash and cash equivalents at beginning of period	13,771	26,409
Cash and cash equivalents at end of period	$ 108,353	$ 71,074