v3.26.1
Long-Term Debt
3 Months Ended
Mar. 31, 2026
Debt Disclosure [Abstract]  
Long-Term Debt Long-Term Debt
Our outstanding long-term debt is shown below: 
March 31,December 31,
(in millions)20262025
Uncollateralized Senior Notes:
5.68% notes, due June 2026$2.9 $2.9 
6.39% notes, due December 2026100.0 100.0 
6.44% notes, due December 2027100.0 100.0 
6.43% notes, due May 20282.1 2.1 
4.88% notes, due August 202860.0 60.0 
3.73% notes, due December 20286.0 6.0 
6.45% notes, due December 2028100.0 100.0 
3.88% notes, due May 202920.0 20.0 
5.20% notes, due November 2029100.0 100.0 
5.02% notes, due September 203050.0 50.0 
6.62% notes, due December 2030100.0 100.0 
5.16% notes, due August 203190.0 90.0 
3.25% notes, due April 203243.8 45.5 
6.71% notes, due December 2033100.0 100.0 
2.98% notes, due December 203463.0 63.0 
3.00% notes, due July 203550.0 50.0 
2.96% notes, due August 203540.0 40.0 
2.49% notes, due January 203750.0 50.0 
5.43% notes, due March 203880.0 80.0 
3.48% notes, due May 203850.0 50.0 
3.58% notes, due November 203850.0 50.0 
6.73% notes, due December 203850.0 50.0 
3.98% notes, due August 2039100.0 100.0 
2.95% notes, due March 204250.0 50.0 
Equipment security note
2.46% note, due September 20315.6 5.8 
Less: debt issuance costs(3.5)(3.6)
Total long-term debt1,459.9 1,461.7 
Less: current maturities(134.6)(134.6)
Total long-term debt, net of current maturities$1,325.3 $1,327.1 
    

Terms of the Senior Notes

All of our outstanding Senior Notes set forth certain business covenants to which we are subject when any note is outstanding, including covenants that limit or restrict our ability, and the ability of our subsidiaries, to incur indebtedness, or place or permit liens and encumbrances on any of our property or the property of our subsidiaries.

Senior Notes
In August 2025, we entered into a Note Purchase Agreement for the issuance of Senior Notes in the aggregate principal amount of $200.0 million with an initial funding of $150.0 million in August 2025 and an additional $50.0 million in September 2025. These Senior Notes have an average interest rate of 5.04 percent consisting of $60.0 million of 4.88 percent notes due in August 2028, $50.0 million of 5.02 percent notes due in September 2030, and $90.0 million of 5.16 percent notes due in August 2031. The proceeds received were used to reduce short-term borrowings under our Revolver and to fund capital expenditures. The outstanding principal balance of the Senior Notes will be due on their respective maturity dates with interest payments payable semiannually beginning in 2026
until the principal has been paid in full. These Senior Notes have similar covenants and default provisions as our other Senior Notes.

Shelf Agreements
We have entered into Shelf Agreements with Prudential and MetLife, however neither of such lenders have any obligation to purchase debt thereunder. We amended these agreements with Prudential and MetLife in February 2026 and June 2025, respectively, to expand the total borrowing capacity and extend the term of the agreements. At March 31, 2026, a total of $343.3 million of borrowing capacity was available under these agreements with terms that extend through February 2029 and June 2030, respectively.