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FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) resulting from the change in the fair value of investments		$ 47,400
Proceeds from sale of long-term investments		22,042	$ 0	$ 0
Gain (loss) on investment securities		57,937	6,727	(8,720)
Geothermal Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other debt securities	$ 2,700	23,700	2,700
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	2,865	$ 23,745	$ 2,865	0
Galileo Technologies | Convertible Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate (as a percent)		5.00%
ADNOC Drilling
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire investments	$ 100,000
Investment balance (in shares)	159,700,000		159,700,000
Investments lockup period (in years)	3 years
ADNOC Drilling | ADNOC Drilling
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership percentage (as a percent)	1.00%		1.00%
Galileo Technologies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire investments		$ 33,000
Galileo Technologies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 500	$ 33,565	$ 500	$ 500
Schlumberger, Ltd
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Sale of equity securities, number of shares sold (in shares)		467,500
Proceeds from sale of long-term investments		$ 22,000
Gain (loss) on investment securities		8,200
Gain (loss) on sale of investment securities		500
Gain (loss) on valuation adjustment of investment		$ 7,700

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