Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012
Segment Information
Number of reporting units	4
Number of reportable segments	2
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	$ 61,781	$ 139,909
Segment (loss) profit	(15,658)	25,354
Interest income, net	192	203
Amortization	(856)	(1,215)
Equity-based compensation	(2,579)	(3,130)
Restructuring	(531)	(63)
(Loss) income from continuing operations before income taxes	(19,432)	21,149
LED And Solar
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	42,307	95,574
Segment (loss) profit	(11,222)	17,486
Amortization	(532)	(863)
Equity-based compensation	(710)	(1,006)
Restructuring	(423)	(58)
(Loss) income from continuing operations before income taxes	(12,887)	15,559
Data Storage
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Net sales	19,474	44,335
Segment (loss) profit	375	8,953
Amortization	(324)	(352)
Equity-based compensation	(130)	(411)
Restructuring	(50)	(5)
(Loss) income from continuing operations before income taxes	(129)	8,185
Unallocated Corporate
Reconciliation of Segment profit (loss) to Income (loss) from continuing operations before income tax
Segment (loss) profit	(4,811)	(1,085)
Interest income, net	192	203
Equity-based compensation	(1,739)	(1,713)
Restructuring	(58)
(Loss) income from continuing operations before income taxes	$ (6,416)	$ (2,595)