v3.25.4
REVENUE - Contract Assets and Deferred Commission Cost Assets (Details) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items]    
Balance, beginning of year $ 268 $ 276
Additions from new contracts with customers, net of terminations and renewals 190 173
Amortization of contract assets to accounts receivable / Amortization recognized on deferred commission cost assets (205) (181)
Balance, end of year 253 268
Current 151 171
Long-term 102 97
Deferred commission costs assets    
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items]    
Balance, beginning of year 753 488
Additions from new contracts with customers, net of terminations and renewals 711 640
Amortization of contract assets to accounts receivable / Amortization recognized on deferred commission cost assets (514) (375)
Balance, end of year 950 753
Current 500 417
Long-term $ 450 $ 336