v3.25.4
Capital - Summary of Change in Capital (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of classes of share capital [line items]    
Balance $ 12,006 $ 11,064
Shares issued under DRIP 34 29
Stock compensation plans 104 79
Repurchases of common shares (1,016) (249)
Balance 11,914 12,006
Stated share capital [member]    
Disclosure of classes of share capital [line items]    
Balance 1,957 1,791
Shares issued under DRIP 34 29
Stock compensation plans 132 152
Balance 2,079 1,957
Contributed Surplus [Member]    
Disclosure of classes of share capital [line items]    
Balance 1,431 1,504
Shares issued under DRIP 0 0
Stock compensation plans (23) (73)
Balance 1,408 1,431
Total Capital [Member]    
Disclosure of classes of share capital [line items]    
Balance 3,498 3,405
Shares issued under DRIP 34 29
Stock compensation plans 109 79
Repurchases of common shares (44) (15)
Balance 3,597 3,498
Repurchases of common shares [member] | Stated share capital [member]    
Disclosure of classes of share capital [line items]    
Repurchases of common shares (44) (15)
Repurchases of common shares [member] | Contributed Surplus [Member]    
Disclosure of classes of share capital [line items]    
Repurchases of common shares 0 0
Repurchases of common shares [member] | Total Capital [Member]    
Disclosure of classes of share capital [line items]    
Repurchases of common shares $ (44) $ (15)
Number of Common Shares [Member]    
Disclosure of classes of share capital [line items]    
Balance, number of shares 450,010,485 452,962,832
Shares issued under DRIP, number of shares 202,433 180,659
Stock compensation plans, number of shares 772,009 942,756
Beginning balance, number of shares 444,962,490 450,010,485
Number of Common Shares [Member] | Repurchases of common shares [member]    
Disclosure of classes of share capital [line items]    
Repurchases of common shares, number of shares (6,022,437) (4,075,762)
Series II, cumulative redeemable preference share capital [Member]    
Disclosure of classes of share capital [line items]    
Balance $ 110 $ 110
Shares issued under DRIP 0 0
Stock compensation plans 0 0
Balance 110 110
Series II, cumulative redeemable preference share capital [Member] | Repurchases of common shares [member]    
Disclosure of classes of share capital [line items]    
Repurchases of common shares $ 0 $ 0