Inventories, Net and Significant Suppliers - Changes in Reserve for Excess and Obsolete Inventory (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Reserve for Excess and Obsolete Inventory
Balance at beginning of period	$ 4,288	$ 4,205	$ 3,045
Additions charged to costs and expenses	6,702	3,685	3,464
Sell through	(1,825)	(1,242)	(1,116)
(Write-offs)/Foreign exchange effects	(4,027)	(2,360)	(1,188)
Balance at end of period	5,138	4,288	4,205
Inventory scrapped during production	$ 2,000	$ 400	$ 300

Amount of valuation reserve for inventory.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant