Inventory (Tables)

9 Months Ended

Sep. 30, 2016

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, 2016		December 31, 2015
Fuel and other raw materials	$	294	$	343
Spare parts and supplies	343		328
Total	$	637	$	671