v3.25.4
DEBT AND CREDIT AGREEMENTS - Additional Information (Details) - CAD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Jun. 01, 2024
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 3,300,000,000    
Proceeds from long-term debt offering 0 $ 0  
Revolving Credit Facility      
Debt Instrument [Line Items]      
Maximum borrowing capacity 2,300,000,000    
Maximum borrowing capacity 250,000,000   $ 750,000,000
Revolving Credit Facility | Hydro One Inc.      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 3,050,000,000    
Commercial Paper Program      
Debt Instrument [Line Items]      
Maturities days of commercial paper (in days) 365 days