UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 261,185	$ (56,338)
Adjustment for (income) loss from discontinued operations	(857)	383
Income (loss) from continuing operations	260,328	(55,955)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	192,910	203,374
Asset impairment charges	12,097	4,363
Amortization of debt discount and debt issuance costs	664	559
Loss on extinguishment of debt	0	60,083
Provision for credit loss	3,222	669
Stock-based compensation	15,704	14,163
Gain on investment securities	(24,661)	(69,994)
Gain on reimbursement of drilling equipment	(27,298)	(11,702)
Other (gain) loss on sale of assets	(4,898)	313
Deferred income tax expense (benefit)	3,165	(11,597)
Other	2,024	(4,287)
Change in assets and liabilities:
Accounts receivable	(70,680)	(103,751)
Inventories of materials and supplies	(12,116)	158
Prepaid expenses and other	(16,387)	(4,068)
Other noncurrent assets	(1,060)	10,375
Accounts payable	33,610	32,138
Accrued liabilities	(42,614)	(29,322)
Deferred income tax liability	(711)	196
Other noncurrent liabilities	3,006	(16,777)
Net cash provided by operating activities from continuing operations	326,305	18,938
Net cash used in operating activities from discontinued operations	(51)	(42)
Net cash provided by operating activities	326,254	18,896
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(181,479)	(104,482)
Other capital expenditures related to assets held-for-sale	0	(10,550)
Purchase of short-term investments	(64,418)	(68,565)
Purchase of long-term investments	(18,771)	(14,124)
Proceeds from sale of short-term investments	97,744	117,456
Proceeds from asset sales	47,718	34,944
Net cash used in investing activities	(119,206)	(45,321)
CASH FLOWS FROM FINANCING ACTIVITIES:
Dividends paid	(102,941)	(54,007)
Payments for employee taxes on net settlement of equity awards	(14,410)	(5,503)
Payment of contingent consideration from acquisition of business	(250)	(250)
Payments for early extinguishment of long-term debt	0	(487,148)
Make-whole premium payment	0	(56,421)
Share repurchases	(145,013)	(76,999)
Other	(540)	(587)
Net cash used in financing activities	(263,154)	(680,915)
Net decrease in cash and cash equivalents and restricted cash	(56,106)	(707,340)
Cash and cash equivalents and restricted cash, beginning of period	269,009	936,716
Cash and cash equivalents and restricted cash, end of period	212,903	229,376
Cash paid during the period:
Interest paid	8,919	10,798
Income tax paid	118,090	695
Income tax received	25,687	62
Payments for operating leases	5,970	6,069
Non-cash operating and investing activities:
Change in accounts payable and accrued liabilities related to purchases of property, plant and equipment	$ 601	$ (2,431)