Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Schedule of Inventory Components

	March 31, 2018		December 31, 2017
Finished goods	$	718	$	669
Work-in-process	1,406		1,349
Purchased raw materials	435		381
Operating supplies	89		81
Total inventories	$	2,648	$	2,480