Business segments

12 Months Ended

Dec. 31, 2017

Century Aluminum is a producer of primary aluminum, which trades as a global commodity. We are organized as a holding company with each of our operating primary aluminum smelters managed and operated as a separate facility reporting to our corporate headquarters. Each of our operating primary aluminum smelters meets the definition of an operating segment. We evaluated the similar economic and other characteristics, including nearly identical products, production processes, customers and distribution and have aggregated our four operating segments into one reportable segment, primary aluminum, based on these factors. In addition, all of our primary aluminum smelters share several key economic factors inherent in their common products and production processes. For example, all of our facilities' revenue is based on the LME price for primary aluminum.

A reconciliation of our consolidated assets to the total of primary aluminum segment assets is provided below.



Segment assets ⁽¹⁾	2017		2016		2015
Primary	$	1,530,975	$	1,492,964	$	1,706,032
Corporate, unallocated	50,666		47,363		46,436
Total assets	$	1,581,641	$	1,540,327	$	1,752,468


⁽¹⁾	Segment assets include accounts receivable, due from affiliates, prepaid and other current assets, inventory, intangible assets and property, plant and equipment — net; the remaining assets are unallocated corporate assets.

Geographic information

Included in the consolidated financial statements are the following amounts related to geographic locations:



	2017		2016		2015
Net sales:
United States	$	938,333	$	808,912	$	1,373,714
Iceland	650,747		510,182		576,143
Long-lived assets: ⁽¹⁾
United States	$	370,029	$	395,107	$	408,722
Iceland	582,981		625,897		801,268
Other	74,957		78,701		94,421


⁽¹⁾	Includes long-lived assets other than financial instruments and deferred taxes.

Major customer information

Over the last three years, only sales revenue from Glencore exceeded 10% of our net sales. A loss of this customer could have a material adverse effect on our results of operations. The net sales revenue related to Glencore is as follows:



	Year Ended December 31,
	2017		2016		2015
Glencore	$	1,198,076	$	1,178,631	$	1,867,711