v3.25.4
DEBT AND CREDIT AGREEMENTS - Summary of Credit Facilities (Details) - CAD ($)
Dec. 31, 2025
Jun. 01, 2024
Line of Credit Facility [Line Items]    
Total Amount $ 3,300,000,000  
Amount Drawn 0  
Revolving Credit Facility    
Line of Credit Facility [Line Items]    
Total Amount 250,000,000 $ 750,000,000
Amount Drawn 0  
Hydro One Inc. | Revolving Credit Facility    
Line of Credit Facility [Line Items]    
Total Amount 3,050,000,000  
Amount Drawn $ 0