Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 item	Jun. 30, 2012
Segment Information
Number of reportable segments			2
Number of reporting units			4
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	$ 97,435	$ 136,547	$ 159,216	$ 276,456
Segment profit (loss)	(2,244)	20,319	(17,902)	45,673
Interest income, net	236	329	428	532
Amortization	(855)	(1,185)	(1,711)	(2,400)
Equity-based compensation	(3,713)	(4,014)	(6,292)	(7,144)
Restructuring			(531)	(63)
Income (loss) from continuing operations before income taxes	(6,576)	15,449	(26,008)	36,598
LED And Solar
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	75,933	86,778	118,240	182,352
Segment profit (loss)	3,124	9,587	(8,098)	27,073
Amortization	(532)	(861)	(1,064)	(1,724)
Equity-based compensation	(1,316)	(1,096)	(2,026)	(2,102)
Restructuring			(423)	(58)
Income (loss) from continuing operations before income taxes	1,276	7,630	(11,611)	23,189
Data Storage
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	21,502	49,769	40,976	94,104
Segment profit (loss)	(121)	12,136	254	21,089
Amortization	(323)	(324)	(647)	(676)
Equity-based compensation	(488)	(440)	(618)	(851)
Restructuring			(50)	(5)
Income (loss) from continuing operations before income taxes	(932)	11,372	(1,061)	19,557
Unallocated Corporate
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Segment profit (loss)	(5,247)	(1,404)	(10,058)	(2,489)
Interest income, net	236	329	428	532
Equity-based compensation	(1,909)	(2,478)	(3,648)	(4,191)
Restructuring			(58)
Income (loss) from continuing operations before income taxes	$ (6,920)	$ (3,553)	$ (13,336)	$ (6,148)