XML 97 R9.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Inventory (Tables)
 12 Months Ended
Dec. 31, 2019
Disclosure of inventories [Abstract]  
Disclosure Of The Components Of Inventories
The components of inventory are as follows:
As at Dec. 3120192018
Parts and materials108  113  
Coal130  108  
Deferred stripping costs6  7  
Natural gas3  4  
Purchased emission credits4  10  
Total251  242  
Disclosure Of The Change In Inventory
The change in inventory is as follows:
Balance, Dec. 31, 2017219  
Net addition20  
Change in foreign exchange rates3  
Balance, Dec. 31, 2018242  
Net addition12  
Change in foreign exchange rates(3) 
Balance, Dec. 31, 2019251