Property, Plant, and Equipment - Net (Tables)

12 Months Ended

Dec. 31, 2018

Property Plant And Equipment [Abstract]

Summary of Property,Plant And Equipment - net

	December 31,
	2018		2017
Cost
Construction in progress	$	34,217	$	34,566
Plant and buildings		29,195		30,851
Machinery and equipment		39,345		39,678
Motor vehicles		1,449		1,710
Office equipment and furniture		2,942		2,736
Leasehold improvements		12,336		12,972
Total cost	$	119,484	$	122,513
Less: Accumulated depreciation
Construction in progress	$	—	$	—
Plant and buildings		11,021		10,380
Machinery and equipment		26,338		24,808
Motor vehicles		1,009		1,333
Office equipment and furniture		2,064		2,000
Leasehold improvements		8,132		7,562
Total accumulated depreciation	$	48,564	$	46,083
Property, plant and equipment, net	$	70,920	$	76,430