XML 75 R46.htm IDEA: XBRL DOCUMENT v3.20.1
Inventory (Tables)
12 Months Ended
Dec. 31, 2019
Inventory Disclosure [Abstract]  
Schedule of Inventory
Inventory consisted of:
 As of December 31,
(In millions)20192018
Fuel oil$73  $74  
Coal93  97  
Natural gas21  28  
Spare parts196  213  
Total Inventory$383  $412