Segment Information and Enterprise-Wide Disclosure (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Segment Reporting Revenue Reconciling [Line Items]
Total sales	$ 248,949	$ 201,951	$ 464,640	$ 383,485
Inter-company sales	(79,143)	(52,798)	(133,279)	(97,485)
Net sales	169,806	149,153	331,361	286,000
Property, plant and equipment	229,793	184,243	229,793	184,243	200,745
Total assets	923,064	772,691	923,064	772,691	846,550
Percentage of net sales	100.00%	100.00%	100.00%	100.00%
Asia [Member]
Segment Reporting Revenue Reconciling [Line Items]
Total sales	150,015	122,170	281,570	231,231
Inter-company sales	(24,128)	(12,558)	(38,577)	(22,093)
Net sales	125,887	109,612	242,993	209,138
Property, plant and equipment	162,654	123,614	162,654	123,614
Total assets	512,542	427,116	512,542	427,116
North America [Member]
Segment Reporting Revenue Reconciling [Line Items]
Total sales	37,224	37,010	72,597	69,611
Inter-company sales	(15,878)	(14,099)	(31,210)	(25,196)
Net sales	21,346	22,911	41,387	44,415
Property, plant and equipment	34,459	29,783	34,459	29,783
Total assets	183,362	161,560	183,362	161,560
Europe [Member]
Segment Reporting Revenue Reconciling [Line Items]
Total sales	61,710	42,771	110,473	82,643
Inter-company sales	(39,137)	(26,141)	(63,492)	(50,196)
Net sales	22,573	16,630	46,981	32,447
Property, plant and equipment	32,680	30,846	32,680	30,846
Total assets	227,160	184,015	227,160	184,015
China [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	53,129	46,898	100,565	88,957
Percentage of net sales	31.00%	31.00%	30.00%	31.00%
Taiwan [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	36,581	34,803	74,261	67,806
Percentage of net sales	22.00%	23.00%	23.00%	24.00%
United States [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	29,928	32,584	56,457	61,789
Percentage of net sales	18.00%	22.00%	17.00%	22.00%
Korea [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	10,422	8,558	20,189	16,888
Percentage of net sales	6.00%	6.00%	6.00%	6.00%
Germany [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	7,999	10,121	17,456	17,152
Percentage of net sales	5.00%	7.00%	5.00%	6.00%
Singapore [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	6,027	6,018	11,589	11,369
Percentage of net sales	3.00%	4.00%	4.00%	4.00%
England [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	8,510	1,817	17,228	6,675
Percentage of net sales	5.00%	1.00%	5.00%	2.00%
All Others [Member]
Segment Reporting Revenue Reconciling [Line Items]
Net sales	$ 17,210	$ 8,354	$ 33,616	$ 15,364
Percentage of net sales	10.00%	6.00%	10.00%	5.00%