v3.24.2
FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Schedule of Assets Measured at Fair Value (Details) - USD ($)
$ in Thousands
Jun. 30, 2024
Mar. 31, 2024
Sep. 30, 2023
Short-term investments:      
Total short-term investments $ 86,088   $ 93,600
Nonrecurring fair value measurements      
Total 264,769   239,145
Geothermal Investments      
Liabilities      
Equity securities   $ 27,200 25,200
Recurring Fair Value Measurements      
Long-term Investments:      
Non-qualified supplemental savings plan 16,634   14,597
Nonrecurring fair value measurements      
Total 260,698   236,715
Liabilities      
Contingent consideration 5,000   9,455
Recurring Fair Value Measurements | ADNOC Drilling      
Long-term Investments:      
Equity securities, investment 178,235   174,758
Recurring Fair Value Measurements | Tamboran Resources Limited      
Long-term Investments:      
Equity securities, investment 23,018   9,920
Recurring Fair Value Measurements | Galileo Technologies      
Long-term Investments:      
Debt securities, investment 36,751   35,434
Recurring Fair Value Measurements | Geothermal Investments      
Long-term Investments:      
Debt securities, investment 2,000   2,006
Recurring Fair Value Measurements | Other      
Long-term Investments:      
Debt securities, investment 4,060    
Fair Value, Nonrecurring      
Nonrecurring fair value measurements      
Other equity securities 4,071   2,430
Total 4,071   2,430
Liabilities      
Debt security investments 300    
Fair Value, Nonrecurring | Other      
Long-term Investments:      
Equity securities, investment     3,000
Liabilities      
Equity securities     600
Level 1      
Short-term investments:      
Total short-term investments 48,870   44,836
Nonrecurring fair value measurements      
Total 221,697   199,275
Level 1 | Recurring Fair Value Measurements      
Long-term Investments:      
Non-qualified supplemental savings plan 16,634   14,597
Nonrecurring fair value measurements      
Total 221,697   199,275
Liabilities      
Contingent consideration 0   0
Level 1 | Recurring Fair Value Measurements | ADNOC Drilling      
Long-term Investments:      
Equity securities, investment 178,235   174,758
Level 1 | Recurring Fair Value Measurements | Tamboran Resources Limited      
Long-term Investments:      
Equity securities, investment 23,018   9,920
Level 1 | Recurring Fair Value Measurements | Galileo Technologies      
Long-term Investments:      
Debt securities, investment 0   0
Level 1 | Recurring Fair Value Measurements | Geothermal Investments      
Long-term Investments:      
Debt securities, investment 0   0
Level 1 | Recurring Fair Value Measurements | Other      
Long-term Investments:      
Debt securities, investment 3,810    
Level 1 | Fair Value, Nonrecurring      
Nonrecurring fair value measurements      
Other equity securities 0   0
Total 0   0
Level 2      
Short-term investments:      
Total short-term investments 37,218   48,764
Nonrecurring fair value measurements      
Total 0   0
Level 2 | Recurring Fair Value Measurements      
Long-term Investments:      
Non-qualified supplemental savings plan 0   0
Nonrecurring fair value measurements      
Total 0   0
Liabilities      
Contingent consideration 0   0
Level 2 | Recurring Fair Value Measurements | ADNOC Drilling      
Long-term Investments:      
Equity securities, investment 0   0
Level 2 | Recurring Fair Value Measurements | Tamboran Resources Limited      
Long-term Investments:      
Equity securities, investment 0   0
Level 2 | Recurring Fair Value Measurements | Galileo Technologies      
Long-term Investments:      
Debt securities, investment 0   0
Level 2 | Recurring Fair Value Measurements | Geothermal Investments      
Long-term Investments:      
Debt securities, investment 0   0
Level 2 | Recurring Fair Value Measurements | Other      
Long-term Investments:      
Debt securities, investment 0    
Level 2 | Fair Value, Nonrecurring      
Nonrecurring fair value measurements      
Other equity securities 0   0
Total 0   0
Level 3      
Short-term investments:      
Total short-term investments 0   0
Nonrecurring fair value measurements      
Total 43,072   39,870
Level 3 | Recurring Fair Value Measurements      
Long-term Investments:      
Non-qualified supplemental savings plan 0   0
Debt securities, investment 36,751    
Nonrecurring fair value measurements      
Total 39,001   37,440
Liabilities      
Contingent consideration 5,000   9,455
Level 3 | Recurring Fair Value Measurements | ADNOC Drilling      
Long-term Investments:      
Equity securities, investment 0   0
Level 3 | Recurring Fair Value Measurements | Tamboran Resources Limited      
Long-term Investments:      
Equity securities, investment 0   0
Level 3 | Recurring Fair Value Measurements | Galileo Technologies      
Long-term Investments:      
Debt securities, investment 36,751   35,434
Level 3 | Recurring Fair Value Measurements | Geothermal Investments      
Long-term Investments:      
Debt securities, investment 2,000   2,006
Level 3 | Recurring Fair Value Measurements | Other      
Long-term Investments:      
Debt securities, investment 250    
Level 3 | Fair Value, Nonrecurring      
Nonrecurring fair value measurements      
Other equity securities 4,071   2,430
Total 4,071   2,430
Liabilities      
Equity securities, fair value     2,400
Corporate and municipal debt securities      
Short-term investments:      
Total short-term investments 37,218   48,764
Corporate and municipal debt securities | Level 1      
Short-term investments:      
Total short-term investments 0   0
Corporate and municipal debt securities | Level 2      
Short-term investments:      
Total short-term investments 37,218   48,764
Corporate and municipal debt securities | Level 3      
Short-term investments:      
Total short-term investments 0   0
U.S. government and federal agency securities      
Short-term investments:      
Total short-term investments 48,870   44,836
U.S. government and federal agency securities | Level 1      
Short-term investments:      
Total short-term investments 48,870   44,836
U.S. government and federal agency securities | Level 2      
Short-term investments:      
Total short-term investments 0   0
U.S. government and federal agency securities | Level 3      
Short-term investments:      
Total short-term investments $ 0   $ 0