Intangible and Other Assets (Tables)

12 Months Ended

Dec. 31, 2017

Intangible And Other Assets [Abstract]

Summary of Intangible Assets

Following is a summary of intangible assets as of December 31:

		2017				2016
	Weighted Average Life	Gross Amount		Accumulated Amortization		Gross Amount		Accumulated Amortization
Intangibles:
Patents and licenses, software and hardware designs	6 years	$	5,320	$	3,540	$	5,033	$	3,187
Developed technology	10 years		2,782		2,295		2,782		2,017
Customer relationships and non-compete	9 years		2,838		2,621		2,838		2,331
		$	10,940	$	8,456	$	10,653	$	7,535

Other Assets

Following is a summary of other assets as of December 31:

	2017		2016
Other assets:
Bauxite raw materials:
Inventories	$	3,527	$	3,989
Other assets		5,434		1,524
	$	8,961	$	5,513