XML 83 R71.htm IDEA: XBRL DOCUMENT v3.25.2
FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Schedule of Assets Measured at Fair Value (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Sep. 30, 2024
Short-term investments:    
Total short-term investments $ 21,128  
Total   $ 292,919
Recurring Fair Value Measurements    
Long-term Investments:    
Non-qualified supplemental savings plan 17,436
Total 82,508 70,223
Recurring Fair Value Measurements | Tamboran Resources Limited    
Long-term Investments:    
Investment in Tamboran 22,218 15,633
Recurring Fair Value Measurements | Other    
Long-term Investments:    
Other equity securities 1,632 20,958
Debt securities: 250 4,588
Recurring Fair Value Measurements | Galileo Technologies    
Long-term Investments:    
Debt securities: 38,972 27,044
Recurring Fair Value Measurements | Geothermal Investments    
Long-term Investments:    
Debt securities: 2,000 2,000
Level 1    
Short-term investments:    
Total short-term investments 0  
Total   259,106
Level 1 | Recurring Fair Value Measurements    
Long-term Investments:    
Non-qualified supplemental savings plan 17,436
Total 41,286 40,929
Level 1 | Recurring Fair Value Measurements | Tamboran Resources Limited    
Long-term Investments:    
Investment in Tamboran 22,218 15,633
Level 1 | Recurring Fair Value Measurements | Other    
Long-term Investments:    
Other equity securities 1,632 20,958
Debt securities: 0 4,338
Level 1 | Recurring Fair Value Measurements | Galileo Technologies    
Long-term Investments:    
Debt securities: 0 0
Level 1 | Recurring Fair Value Measurements | Geothermal Investments    
Long-term Investments:    
Debt securities: 0 0
Level 2    
Short-term investments:    
Total short-term investments 21,128  
Total   33,813
Level 2 | Recurring Fair Value Measurements    
Long-term Investments:    
Non-qualified supplemental savings plan 0
Total 0 0
Level 2 | Recurring Fair Value Measurements | Tamboran Resources Limited    
Long-term Investments:    
Investment in Tamboran 0 0
Level 2 | Recurring Fair Value Measurements | Other    
Long-term Investments:    
Other equity securities 0 0
Debt securities: 0 0
Level 2 | Recurring Fair Value Measurements | Galileo Technologies    
Long-term Investments:    
Debt securities: 0 0
Level 2 | Recurring Fair Value Measurements | Geothermal Investments    
Long-term Investments:    
Debt securities: 0 0
Level 3    
Short-term investments:    
Total short-term investments 0  
Total   0
Level 3 | Recurring Fair Value Measurements    
Long-term Investments:    
Non-qualified supplemental savings plan 0
Total 41,222 29,294
Level 3 | Recurring Fair Value Measurements | Tamboran Resources Limited    
Long-term Investments:    
Investment in Tamboran 0 0
Level 3 | Recurring Fair Value Measurements | Other    
Long-term Investments:    
Other equity securities 0 0
Debt securities: 250 250
Level 3 | Recurring Fair Value Measurements | Galileo Technologies    
Long-term Investments:    
Debt securities: 38,972 27,044
Level 3 | Recurring Fair Value Measurements | Geothermal Investments    
Long-term Investments:    
Debt securities: 2,000 2,000
Corporate and municipal debt securities    
Short-term investments:    
Total short-term investments 21,128 33,813
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 21,128 33,813
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   53,490
U.S. government and federal agency securities | Level 1    
Short-term investments:    
Total short-term investments   53,490
U.S. government and federal agency securities | Level 2    
Short-term investments:    
Total short-term investments   0
U.S. government and federal agency securities | Level 3    
Short-term investments:    
Total short-term investments   0
Investment in ADNOC Drilling    
Short-term investments:    
Total short-term investments   205,616
Investment in ADNOC Drilling | Level 1    
Short-term investments:    
Total short-term investments   205,616
Investment in ADNOC Drilling | Level 2    
Short-term investments:    
Total short-term investments   0
Investment in ADNOC Drilling | Level 3    
Short-term investments:    
Total short-term investments   $ 0