Quarterly Results of Operations (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Results of Operations (unaudited)
Revenue	$ 58,574,000	$ 48,831,000	$ 47,501,000	$ 40,726,000	$ 44,624,000	$ 44,640,000	$ 59,114,000	$ 55,007,000	$ 195,632,000	$ 203,385,000	$ 319,416,000
Gross profit	21,280,000	16,976,000	16,737,000	12,943,000	480,000	14,367,000	22,788,000	20,536,000	67,935,000	58,171,000	114,737,000
Net income (loss)	614,000	(4,750,000)	(4,019,000)	(8,988,000)	(14,818,000)	(8,718,000)	(471,000)	(10,027,000)	(17,144,000)	(34,034,000)	5,077,000
Net income (loss) per share basic and diluted (in dollars per share)	$ 0.01	$ (0.04)	$ (0.04)	$ (0.08)	$ (0.14)	$ (0.08)	$ 0.00	$ (0.09)
Tax expense related to an uncertain tax position in a certain foreign jurisdiction	400,000				400,000		800,000
Write off of deferred tax assets in foreign jurisdictions		400,000
Restructuring charges			400,000	1,800,000	600,000	600,000	100,000	2,900,000	2,334,000	4,169,000
Gain on sale of dry strip assets and intellectual property			800,000	400,000					1,167,000	7,904,000
Charge to excess and obsolete inventory				2,100,000					2,562,000	14,492,000	1,015,000
Quarterly charges and expenses
Gain on sale of dry strip assets and intellectual property			800,000	400,000					1,167,000	7,904,000
Restructuring charges			400,000	1,800,000	600,000	600,000	100,000	2,900,000	2,334,000	4,169,000
One-time marketing expense					2,100,000
Dry strip product line, intellectual property rights and certain assets
Quarterly Results of Operations (unaudited)
Gain on sale of dry strip assets and intellectual property									1,200,000	7,900,000
Quarterly charges and expenses
Gain on sale of dry strip assets and intellectual property									1,200,000	7,900,000
Inventory reserves
Quarterly Results of Operations (unaudited)
Gain on sale of dry strip assets and intellectual property					7,900,000
Quarterly charges and expenses
Provision for excess inventory					13,400,000				2,562,000	14,492,000	1,015,000
Gain on sale of dry strip assets and intellectual property					$ 7,900,000