XML 407 R126.htm IDEA: XBRL DOCUMENT v3.25.0.1
Contributed equity - Summary of Information about Shares Reserved for Employee Share Plans (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Employee Share Plans [Member]      
Disclosure of classes of share capital [line items]      
Beginning balance, shares 2,140,927 1,873,777 1,819,744
Beginning balance $ (49) $ (38) $ (30)
Purchases during the year, shares 4,293,699 2,332,121 2,232,589
Purchases during the year $ (81) $ (57) $ (45)
Vested/allocated during the year, shares (3,353,784) (2,064,971)  
Vested/allocated during the year $ 72 $ 46  
Vested during the year, shares     (2,178,556)
Vested during the year     $ 37
Ending balance, shares 3,080,842 2,140,927 1,873,777
Ending balance $ (58) $ (49) $ (38)
Dividend Reinvestment Plan [Member]      
Disclosure of classes of share capital [line items]      
Beginning balance, shares 0    
Beginning balance $ 0    
Purchases during the year, shares 0   6,823,092
Purchases during the year $ 0   $ (144)
Vested/allocated during the year, shares 0    
Vested/allocated during the year $ 0    
Vested during the year, shares     (6,823,092)
Vested during the year     $ 144
Ending balance, shares 0 0  
Ending balance $ 0 $ 0