CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income	$ 16,002	$ 203,608
Adjustment for (income) loss from discontinued operations	(104)	15
Income from continuing operations	15,898	203,623
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	142,129	138,232
Amortization of debt discount and debt issuance costs	255	58
Provision for bad debt	6
Stock-based compensation	7,921	6,982
Other	233
Income from asset sales	(4,589)	(4,173)
Deferred income tax expense	20,169	124,763
Change in assets and liabilities:
Accounts receivable	72,083	(44,766)
Inventories	1,299	(4,726)
Prepaid expenses and other	(3,657)	(7,048)
Accounts payable	(10,554)	4,784
Accrued liabilities	74,170	(37,097)
Deferred income taxes	3,487	(278)
Other noncurrent liabilities	(10,758)	12,970
Net cash provided by operating activities from continuing operations	308,092	393,324
Net cash used in operating activities from discontinued operations	104	(15)
Net cash provided by operating activities	308,196	393,309
INVESTING ACTIVITIES:
Capital expenditures	(114,470)	(369,981)
Purchase of short-term investments	(6,918)
Proceeds from sales of short-term investments	4,600
Proceeds from asset sales	6,058	7,160
Net cash used in investing activities	(110,730)	(362,821)
FINANCING ACTIVITIES:
Dividends paid	(74,560)	(74,822)
Repurchase of common stock		(59,654)
Debt issuance costs	(32)
Exercise of stock options, net of tax withholding	(59)	(2,062)
Tax withholdings related to net share settlements of restricted stock	(3,617)	(4,248)
Tax benefit (expense) from share-based compensation	(352)	2,723
Net cash used in financing activities	(78,620)	(138,063)
Net increase (decrease) in cash and cash equivalents	118,846	(107,575)
Cash and cash equivalents, beginning of period	729,384	360,307
Cash and cash equivalents, end of period	$ 848,230	$ 252,732