Inventories, Net and Significant Suppliers - Changes in Reserve for Excess and Obsolete Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Reserve for Excess and Obsolete Inventory [Rollforward]
Balance at beginning of period	$ 4,288	$ 4,205
Additions charged to costs and expenses	643	632
Sell through	(315)	(354)
(Write-offs)/Foreign exchange effects	(388)	(274)
Balance at end of period	4,228	4,209
Inventory written-off and scrapped during production	$ 113	$ 27