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Long-Term Debt - Schedule of Long-Term Debt (Details) - CAD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Debt Instrument [Line Items] |  |
Total long-term debt | $ 33,405 | $ 29,703
Less: Deferred financing costs and debt discounts | (191) | (172)
Less: Current installments of long-term debt | (1,990) | (2,296)
Long-term debt | 31,224 | 27,235
Long-term Credit Facility Borrowings |  |
Debt Instrument [Line Items] |  |
Total long-term debt | 2,216 | 1,572
Credit facility |  |
Debt Instrument [Line Items] |  |
Less: Current installments of long-term debt | $ (1,860) | $ (1,160)
Long-term debt weighted average interest rate (percent) | 4.60% | 6.20%
Credit facility | Long-term Credit Facility Borrowings |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 2,216 | $ 1,572
ITC |  |
Debt Instrument [Line Items] |  |
Fair value adjustment - ITC acquisition | 88 | 89
ITC | Unsecured | Fixed Rate Unsecured US Senior Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 5,610 | $ 5,165
Long-term debt weighted average interest rate (percent) | 4.37% | 4.16%
ITC | Unsecured | Fixed Rate Unsecured US Shareholder Note |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 286 | $ 263
Stated interest rate | 6.00% | 6.00%
ITC | Secured | Fixed Rate Secured US First Mortgage Bonds |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 3,944 | $ 3,268
Long-term debt weighted average interest rate (percent) | 4.34% | 4.22%
ITC | Secured | Fixed Rate Secured US Senior Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 1,511 | $ 1,278
Long-term debt weighted average interest rate (percent) | 4.16% | 4.00%
UNS Energy | Unsecured | Fixed Rate Unsecured US Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 4,172 | $ 3,668
Long-term debt weighted average interest rate (percent) | 4.09% | 3.80%
Central Hudson | Unsecured | Fixed and Variable Rate Unsecured US Promissory Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 1,974 | $ 1,687
Long-term debt weighted average interest rate (percent) | 4.38% | 4.27%
FortisBC Energy | Unsecured | Fixed Rate Unsecured Debentures |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 3,295 | $ 3,295
Long-term debt weighted average interest rate (percent) | 4.61% | 4.61%
FortisAlberta | Unsecured | Fixed Rate Unsecured Debentures |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 2,835 | $ 2,685
Long-term debt weighted average interest rate (percent) | 4.63% | 4.52%
FortisBC Electric | Unsecured | Fixed Rate Unsecured Debentures |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 960 | $ 860
Long-term debt weighted average interest rate (percent) | 4.72% | 4.70%
Other Electric | Unsecured | Fixed Rate Unsecured Senior Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 207 | $ 152
Long-term debt weighted average interest rate (percent) | 4.61% | 4.45%
Other Electric | Unsecured | Fixed and Variable Rate Unsecured US Senior Loan Notes and Bonds |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 876 | $ 702
Long-term debt weighted average interest rate (percent) | 5.03% | 4.89%
Other Electric | Secured | Fixed Rate Secured First Mortgage Sinking Fund Bonds |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 739 | $ 748
Long-term debt weighted average interest rate (percent) | 5.24% | 5.24%
Other Electric | Secured | Fixed Rate Secured First Mortgage Bonds |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 320 | $ 320
Long-term debt weighted average interest rate (percent) | 5.29% | 5.29%
Corporate and Other | Unsecured | Fixed Rate Unsecured Debentures |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 200 | $ 200
Stated interest rate | 6.51% | 6.51%
Corporate and Other | Unsecured | Fixed Rate Unsecured Senior Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 2,000 | $ 1,500
Long-term debt weighted average interest rate (percent) | 4.11% | 4.10%
Corporate and Other | Unsecured | Fixed Rate Unsecured US Senior Notes and Promissory Notes |  |
Debt Instrument [Line Items] |  |
Total long-term debt | $ 2,172 | $ 2,251
Long-term debt weighted average interest rate (percent) | 3.79% | 3.82%

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