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v3.25.2

Capitalization (Narrative) (Details) $ / shares in Units, $ in Thousands |  |  | 9 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 06, 2025 USD ($) | Feb. 19, 2025 USD ($) | Jun. 30, 2025 USD ($) $ / shares shares | Jun. 30, 2024 USD ($) | Jun. 13, 2025 USD ($) | May 31, 2025 lender | Jan. 30, 2025 | Sep. 30, 2024 USD ($) | Apr. 30, 2024 USD ($) | Mar. 08, 2024 USD ($) | Feb. 14, 2024 USD ($) lender
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  |  |  | $ 200,000 |
Share repurchases (in shares) | shares |  |  | 650,037 |  |  |  |  |  |  |  |
Current Portion of Long-Term Debt |  |  | $ 300,000 |  |  |  |  | $ 500,000 |  |  |
Net Proceeds from Issuance of Long-Term Debt |  |  | 988,731 | $ 299,396 |  |  |  |  |  |  |
Premiums Paid on Early Redemption of Debt |  |  | (2,385) | $ 0 |  |  |  |  |  |  |
Unamortized Debt Expense |  |  | $ 6,701 |  |  |  |  | 5,604 |  |  |
5.50% Notes Due March 15, 2030 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, face amount |  | $ 500,000 |  |  |  |  |  |  |  |  |
Long-term debt, interest rate | 5.50% | 5.50% |  |  |  |  |  |  |  |  |
Net Proceeds from Issuance of Long-Term Debt |  | $ 495,200 |  |  |  |  |  |  |  |  |
Percentage of principal amount |  | 101.00% |  |  |  |  |  |  |  |  |
Maximum interest rate adjustment |  | 2.00% |  |  |  |  |  |  |  |  |
5.50% Notes Due March 15, 2030 | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, interest rate |  | 7.50% |  |  |  |  |  |  |  |  |
5.95% Notes Due March 15, 2035 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, face amount |  | $ 500,000 |  |  |  |  |  |  |  |  |
Long-term debt, interest rate |  | 5.95% |  |  |  |  |  |  |  |  |
Net Proceeds from Issuance of Long-Term Debt |  | $ 493,500 |  |  |  |  |  |  |  |  |
Percentage of principal amount |  | 101.00% |  |  |  |  |  |  |  |  |
Maximum interest rate adjustment |  | 2.00% |  |  |  |  |  |  |  |  |
5.95% Notes Due March 15, 2035 | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, interest rate |  | 7.95% |  |  |  |  |  |  |  |  |
5.50% Notes Due January 2026 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, face amount | $ 500,000 |  |  |  |  |  |  |  |  |  |
Long-term debt, interest rate | 5.50% |  |  |  |  |  |  |  |  |  |
Debt instrument redeemed | $ 503,300 |  |  |  |  |  |  |  |  |  |
5.50% Notes Due January 2026 | Exploration and Production and Gathering |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Premiums Paid on Early Redemption of Debt | 1,800 |  |  |  |  |  |  |  |  |  |
5.50% Notes Due January 2026 | Pipeline and Storage |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Unamortized Debt Expense | 1,500 |  |  |  |  |  |  |  |  |  |
Indenture From 1974 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument redeemed |  |  |  |  | $ 50,000 |  |  |  |  |  |
Carrying amount of long-term debt |  |  |  |  | $ 50,000 |  |  |  |  |  |
Share Repurchase Plan |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Share repurchases (in shares) | shares |  |  | 828,720 |  |  |  |  |  |  |  |
Share repurchase program, average cost per share (in dollars per share) | $ / shares |  |  | $ 64.37 |  |  |  |  |  |  |  |
Share repurchases |  |  | $ 53,800 |  |  |  |  |  |  |  |
Credit Agreement |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  | $ 1,000,000 |  |  |  |  |  |  |  |
Extended term of credit agreement |  |  |  |  |  |  | 1 year |  |  |  |
Number of banks In syndicate | lender |  |  |  |  |  | 12 |  |  |  |  |
7.38% Notes Due June 2025 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Current Portion of Long-Term Debt |  |  |  |  |  |  |  | $ 50,000 |  |  |
Long-term debt, interest rate |  |  |  |  |  |  |  | 7.38% |  |  |
7.38% Notes Due June 2025 | Indenture From 1974 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, interest rate |  |  | 7.38% |  | 7.38% |  |  |  |  |  |
5.20% Notes Due July 2025 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Current Portion of Long-Term Debt | 450,000 |  |  |  |  |  |  | $ 450,000 |  |  |
Long-term debt, face amount | $ 450,000 |  |  |  |  |  |  |  |  |  |
Long-term debt, interest rate | 5.20% |  |  |  |  |  |  | 5.20% |  |  |
Debt instrument redeemed | $ 450,800 |  |  |  |  |  |  |  |  |  |
5.20% Notes Due July 2025 | Exploration and Production and Gathering |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Premiums Paid on Early Redemption of Debt | 600 |  |  |  |  |  |  |  |  |  |
5.20% Notes Due July 2025 | Pipeline and Storage |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Unamortized Debt Expense | $ 200 |  |  |  |  |  |  |  |  |  |
Term Loan Agreement |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  |  |  |  |  |  | $ 300,000
Current Portion of Long-Term Debt |  |  | $ 300,000 |  |  |  |  |  |  |  |
Long-term debt, face amount |  |  |  |  |  |  |  |  | $ 300,000 |  |
Number of lenders | lender |  |  |  |  |  |  |  |  |  |  | 6
Proceeds from debt, net of issuance costs |  |  | $ 299,400 |  |  |  |  |  |  |  |
Rate adjustment to SOFR |  |  | 0.0010 |  |  |  |  |  |  |  |
Spread on variable rate |  |  | 1.375% |  |  |  |  |  |  |  |
Term Loan Agreement | 5.82% Through August 2025 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt, variable interest rate |  |  | 5.82% |  |  |  |  |  |  |  |

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