Debt
Long-term debt
Long-term debt at September 30, 2025 and 2024 consisted of the following:
| | | | | | | | | | | |
| 2025 | | 2024 |
| | (In thousands) |
Unsecured 3.00% Senior Notes, due June 2027 | $ | 500,000 | | | $ | 500,000 | |
Unsecured 2.625% Senior Notes, due September 2029 | 500,000 | | | 500,000 | |
Unsecured 1.50% Senior Notes, due January 2031 | 600,000 | | | 600,000 | |
Unsecured 5.45% Senior Notes, due October 2032 | 300,000 | | | 300,000 | |
Unsecured 5.90% Senior Notes, due November 2033 | 725,000 | | | 725,000 | |
Unsecured 5.95% Senior Notes, due October 2034 | 200,000 | | | 200,000 | |
Unsecured 5.20% Senior Notes, due August 2035 | 500,000 | | | — | |
Unsecured 5.50% Senior Notes, due June 2041 | 400,000 | | | 400,000 | |
Unsecured 4.15% Senior Notes, due January 2043 | 500,000 | | | 500,000 | |
Unsecured 4.125% Senior Notes, due October 2044 | 750,000 | | | 750,000 | |
Unsecured 4.30% Senior Notes, due October 2048 | 600,000 | | | 600,000 | |
Unsecured 4.125% Senior Notes, due March 2049 | 450,000 | | | 450,000 | |
Unsecured 3.375% Senior Notes, due September 2049 | 500,000 | | | 500,000 | |
Unsecured 2.85% Senior Notes, due February 2052 | 600,000 | | | 600,000 | |
Unsecured 5.75% Senior Notes, due October 2052 | 500,000 | | | 500,000 | |
Unsecured 6.20% Senior Notes, due November 2053 | 500,000 | | | 500,000 | |
Unsecured 5.00% Senior Notes, due December 2054 | 650,000 | | | — | |
Medium term Series A notes, 1995-1, 6.67%, due December 2025 | 10,000 | | | 10,000 | |
Unsecured 6.75% Debentures, due July 2028 | 150,000 | | | 150,000 | |
Finance lease obligations (see Note 7) | 47,234 | | | 48,890 | |
| Total long-term debt | 8,982,234 | | | 7,833,890 | |
| Less: | | | |
| Net original issue premium on unsecured senior notes and debentures | (1,332) | | | (9,071) | |
| Debt issuance cost | 64,622 | | | 57,664 | |
| Current maturities | 11,775 | | | 1,651 | |
| $ | 8,907,169 | | | $ | 7,783,646 | |
Maturities of long-term debt, excluding our finance lease obligations, at September 30, 2025 were as follows by fiscal years (in thousands):
| | | | | |
| 2026 | $ | 10,000 | |
| 2027 | 500,000 | |
| 2028 | 150,000 | |
| 2029 | 500,000 | |
| 2030 | — | |
| Thereafter | 7,775,000 | |
| $ | 8,935,000 | |
On October 1, 2025, we completed a public offering of $600 million of 5.45% senior notes due January 2056, with an effective interest rate of 4.85%, after giving effect to the estimated offering costs and settlement of our interest rate swaps. The net proceeds from the offering, after the underwriting discount and estimated offering expenses, of $589.8 million were used for general corporate purposes. In September 2025, we settled the designated interest rate swaps associated with the offering and received $122.9 million.
On June 26, 2025, we completed a public offering of $500 million of 5.20% senior notes due August 2035, with an effective interest rate of 5.35%, after giving effect to the offering costs. The net proceeds from the offering, after the underwriting discount and offering expenses, of $493.7 million were used for general corporate purposes.
On October 1, 2024, we completed a public offering of $650 million of 5.00% senior notes due December 2054, with an effective interest rate of 3.90%, after giving effect to the offering costs and settlement of our interest rate swaps. The net proceeds from the offering, after the underwriting discount and offering expenses, of $639.4 million were used for general corporate purposes. In September 2024, we settled the designated interest rate swaps associated with this offering and received $231.1 million.
On June 21, 2024, we completed a public offering of $325 million of 5.90% senior notes due November 2033, with an effective interest rate of 5.17%, after giving effect to the offering costs. The net proceeds from the offering, after the underwriting discount and offering expenses, of $339.0 million were used for general corporate purposes.
On October 10, 2023, we completed a public offering of $500 million of 6.20% senior notes due November 2053, with an effective interest rate of 5.56%, after giving effect to the offering costs and settlement of our interest rate swaps, and $400 million of 5.90% senior notes due November 2033, with an effective interest rate of 4.35%, after giving effect to the offering costs and settlement of our interest rate swaps. The net proceeds from the offering, after the underwriting discount and offering expenses, of $889.4 million were used for general corporate purposes. In September 2023, we settled the designated interest rate swaps associated with this offering and received $171.1 million.
Short-term Debt
We utilize short-term debt to provide cost-effective, short-term financing until it can be replaced with a balance of long-term debt and equity financing that achieves the Company’s desired capital structure. Our short-term borrowing requirements are driven primarily by construction work in progress and the seasonal nature of the natural gas business.
Our short-term borrowing requirements are satisfied through a combination of a $1.5 billion commercial paper program and four committed revolving credit facilities with third-party lenders that provide $3.1 billion of total working capital funding.
The primary source of our funding is our commercial paper program, which is supported by a five-year unsecured $1.5 billion credit facility that expires on March 28, 2030. This facility bears interest at a base rate or at a Term SOFR-based rate for the applicable interest period, plus a margin ranging from zero percent to 0.25 percent for base rate advances or a margin ranging from 0.75 percent to 1.25 percent for Term SOFR-based advances, based on the Company’s credit ratings. Additionally, the facility contains a $250 million accordion feature, which provides the opportunity to increase the total committed loan to $1.75 billion. At September 30, 2025 and 2024, there were no amounts outstanding under our commercial paper program.
We also have a $1.5 billion three-year senior unsecured credit facility, which expires March 28, 2028, that is used to provide additional working capital funding. This facility bears interest at a base rate or at a Term SOFR-based rate for the applicable interest period, plus a margin ranging from zero percent to 0.25 percent for base rate advances or a margin ranging from 0.75 percent to 1.25 percent for Term SOFR-based advances, based on the Company's credit ratings. Additionally, the facility contains a $250 million accordion feature, which provides the opportunity to increase the total committed loan to $1.75 billion. At September 30, 2025 and 2024, there were no borrowings outstanding under this facility.
Additionally, we have a $50 million 364-day unsecured facility, which was renewed April 1, 2025 and is used to provide working capital funding. There were no borrowings outstanding under this facility as of September 30, 2025 and 2024.
Finally, we have a $50 million 364-day unsecured revolving credit facility, which was renewed March 31, 2025 and is used to issue letters of credit and to provide working capital funding. At September 30, 2025, there were no borrowings outstanding under the new facility; however, outstanding letters of credit reduced the total amount available to us to $44.4 million.
Debt Covenants
The availability of funds under these credit facilities is subject to conditions specified in the respective credit agreements, all of which we currently satisfy. These conditions include our compliance with financial covenants and the continued accuracy of representations and warranties contained in these agreements. We are required by the financial covenants in each of these facilities to maintain, at the end of each fiscal quarter, a ratio of total-debt-to-total-capitalization of no greater than 70 percent. At September 30, 2025, our total-debt-to-total-capitalization ratio, as defined, was 41 percent. In addition, both the interest margin and the fee that we pay on unused amounts under each of these facilities are subject to adjustment depending upon our credit ratings.
These credit facilities and our public indentures contain usual and customary covenants for our business, including covenants substantially limiting liens, substantial asset sales, and mergers. Additionally, our public debt indentures relating to our senior notes and debentures, as well as certain of our revolving credit agreements, each contain a default provision that is triggered if outstanding indebtedness arising out of any other credit agreements in amounts ranging from in excess of $15 million to in excess of $100 million becomes due by acceleration or is not paid at maturity. We were in compliance with all of our debt covenants as of September 30, 2025. If we were unable to comply with our debt covenants, we would likely be required to repay our outstanding balances on demand, provide additional collateral or take other corrective actions.