SEGMENT INFORMATION, Segment Contribution (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Contribution [Abstract]
Operating income	$ 64,739	$ 79,798	$ 111,001	$ 87,947
Other income (expense)	(2,731)	(11,060)	(7,298)	(13,923)
Income before provision for income taxes	62,008	68,738	103,703	74,024
Operating Segment [Member]
Segment Contribution [Abstract]
Operating income	122,951	143,265	226,266	229,300
Operating Segment [Member] | Mainland China [Member]
Segment Contribution [Abstract]
Operating income	52,283	56,709	87,710	75,010
Operating Segment [Member] | South Korea [Member]
Segment Contribution [Abstract]
Operating income	22,278	24,195	46,790	48,252
Operating Segment [Member] | Americas [Member]
Segment Contribution [Abstract]
Operating income	11,646	12,177	21,742	22,649
Operating Segment [Member] | South Asia Pacific [Member]
Segment Contribution [Abstract]
Operating income	14,439	24,348	28,419	36,801
Operating Segment [Member] | Japan [Member]
Segment Contribution [Abstract]
Operating income	10,922	15,933	23,348	27,980
Operating Segment [Member] | Hong Kong/Taiwan [Member]
Segment Contribution [Abstract]
Operating income	7,766	7,070	12,849	15,428
Operating Segment [Member] | EMEA [Member]
Segment Contribution [Abstract]
Operating income	3,617	2,833	5,408	3,180
Corporate and Other [Member]
Segment Contribution [Abstract]
Operating income	$ (58,212)	$ (63,467)	$ (115,265)	$ (141,353)