Inventory (Tables)

9 Months Ended

Sep. 30, 2015

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, 2015		December 31, 2014
Fuel and other raw materials	$	336	$	357
Spare parts and supplies	334		345
Total	$	670	$	702