| Components of debt |
The following table summarizes the major components of debt at principal amounts as of each balance sheet date (in millions) and provides the maturities and interest rate ranges of each major category as of September 30, 2024: | | | | | | | | | September 30, | | December 31, | | | 2024 | | 2023 | Commercial paper program (weighted average interest rate of 5.6% as of December 31, 2023) | | $ | — | | $ | 860 | Senior notes, maturing through 2050, interest rates ranging from 0.75% to 7.75% (weighted average interest rate of 3.9% as of September 30, 2024 and 3.7% as of December 31, 2023) | | | 12,720 | | | 11,376 | Canadian senior notes, C$500 million maturing September 2026, interest rate of 2.6% | | | 370 | | | 378 | Tax-exempt bonds, maturing through 2053, fixed and variable interest rates ranging from 0.70% to 5.0% (weighted average interest rate of 3.7% as of September 30, 2024 and 3.3% as of December 31, 2023) | | | 2,823 | | | 2,883 | Financing leases and other, maturing through 2082 (weighted average interest rate of 4.9% as of September 30, 2024 and 5.0% as of December 31, 2023) (a) | | | 865 | | | 855 | Debt issuance costs, discounts and other | | | (125) | | | (123) | | | | 16,653 | | | 16,229 | Current portion of long-term debt | | | 676 | | | 334 | Long-term debt, less current portion | | $ | 15,977 | | $ | 15,895 |
| (a) | Excluding our landfill financing leases, the maturities of our financing leases and other debt obligations extend through 2059. |
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