XML 62 R37.htm IDEA: XBRL DOCUMENT v3.20.2
Inventory (Tables)
9 Months Ended
Sep. 30, 2020
Inventory Disclosure [Abstract]  
Inventory Balance By Type
The following table summarizes the Company’s inventory balances as of the periods indicated (in millions):
September 30, 2020December 31, 2019
Fuel and other raw materials$227 $230 
Spare parts and supplies247 257 
Total$474 $487