SEGMENT INFORMATION, Segment Contribution (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Contribution [Abstract]
Operating income	$ 64,362	$ 82,374	$ 175,363	$ 170,321
Other income (expense)	(1,172)	(5,695)	(8,470)	(19,618)
Income before provision for income taxes	63,190	76,679	166,893	150,703
Operating Segment [Member]
Segment Contribution [Abstract]
Operating income	121,352	137,156	347,618	366,456
Operating Segment [Member] | Mainland China [Member]
Segment Contribution [Abstract]
Operating income	42,375	38,240	130,085	113,250
Operating Segment [Member] | South Korea [Member]
Segment Contribution [Abstract]
Operating income	23,713	41,739	70,503	89,991
Operating Segment [Member] | Americas [Member]
Segment Contribution [Abstract]
Operating income	12,822	11,637	34,564	34,286
Operating Segment [Member] | South Asia/Pacific [Member]
Segment Contribution [Abstract]
Operating income	18,664	16,371	47,083	53,172
Operating Segment [Member] | Japan [Member]
Segment Contribution [Abstract]
Operating income	12,786	15,510	36,134	43,490
Operating Segment [Member] | Hong Kong/Taiwan [Member]
Segment Contribution [Abstract]
Operating income	8,096	10,401	20,945	25,829
Operating Segment [Member] | EMEA [Member]
Segment Contribution [Abstract]
Operating income	2,896	3,258	8,304	6,438
Corporate and Other [Member]
Segment Contribution [Abstract]
Operating income	$ (56,990)	$ (54,782)	$ (172,255)	$ (196,135)