Inventories, Net and Significant Suppliers - Changes in Reserve for Excess and Obsolete Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Schedule of Reserve for Excess and Obsolete Inventory [Rollforward]
Balance at beginning of period	$ 5,138	$ 4,288
Additions charged to costs and expenses	1,422	643
Sell through	(378)	(315)
(Write-offs)/Foreign exchange effects	(694)	(388)
Balance at end of period	5,488	4,228
Inventory written-off and scrapped during production	$ 1,100	$ 100

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