CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 488,227	$ (83,881)
Adjustment for loss from discontinued operations	10,782	854
Income (loss) from continuing operations	499,009	(83,027)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	288,942	286,624
Amortization of debt discount and debt issuance costs	531	525
Provision for bad debt	429	3,820
Stock-based compensation	15,546	12,479
Income from asset sales	(10,820)	(15,731)
Deferred income tax benefit	(506,373)	(34,038)
Other	5,701	32
Change in assets and liabilities:
Accounts receivable	(61,791)	30,278
Inventories	(5,973)	(7,273)
Prepaid expenses and other	(4,158)	17,830
Accounts payable	(13,119)	31,359
Accrued liabilities	8,418	(76,879)
Deferred income taxes	(5,980)	2,675
Other noncurrent liabilities	(13,272)	(18,316)
Net cash provided by operating activities from continuing operations	197,090	150,358
Net cash used in operating activities from discontinued operations	(96)	(80)
Net cash provided by operating activities	196,994	150,278
INVESTING ACTIVITIES:
Capital expenditures	(191,202)	(175,303)
Purchase of short-term investments	(36,784)	(37,899)
Payment for acquisition of business, net of cash acquired	(47,886)
Proceeds from sale of short-term investments	32,020	34,000
Proceeds from asset sales	17,826	13,459
Net cash used in investing activities	(226,026)	(165,743)
FINANCING ACTIVITIES:
Dividends paid	(153,433)	(152,617)
Proceeds from stock option exercises	1,645	10,372
Payments for employee taxes on net settlement of equity awards	(5,791)	(6,105)
Net cash used in financing activities	(157,579)	(148,350)
Net decrease in cash and cash equivalents	(186,611)	(163,815)
Cash and cash equivalents, beginning of period	521,375	905,561
Cash and cash equivalents, end of period	$ 334,764	$ 741,746