Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Segment		Dec. 31, 2017 USD ($)	[1]
Goodwill [Abstract]
Number of segments | Segment	7
Goodwill	$ 196,573		$ 114,954
Mainland China [Member]
Goodwill [Abstract]
Goodwill	32,179		32,179
Americas/Pacific [Member]
Goodwill [Abstract]
Goodwill	9,449		9,449
South Korea [Member]
Goodwill [Abstract]
Goodwill	29,261		29,261
Southeast Asia [Member]
Goodwill [Abstract]
Goodwill	18,537		18,537
Japan [Member]
Goodwill [Abstract]
Goodwill	16,019		16,019
Hong Kong/Taiwan [Member]
Goodwill [Abstract]
Goodwill	6,634		6,634
EMEA [Member]
Goodwill [Abstract]
Goodwill	2,875		2,875
Other [Member]
Goodwill [Abstract]
Goodwill	$ 81,619	[2]	$ 0

[1] Goodwill was recast to reflect current period presentation by geographic region at December 31, 2018.

[2] The other category represents goodwill allocated to the companies acquired during 2018 (see Note 16 - Acquisitions)