Certain Balance Sheet Components - (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Prepaid expenses and other current assets:
Prepaid Inventories	$ 7,500	[1]	$ 0	[1]
Other Prepayments	10,823		8,736
Deferred cost of revenue	2,656		13,953
Other	542		947
Prepaid expenses and other current assets	21,521		23,636
Inventories:
Raw materials	2,389		10,731
Work-in-process	976		4,347
Finished goods	33,561		49,192
Total inventories, net	36,926		64,270
Property and equipment:
Furniture and fixtures	8,227		7,856
Machinery and equipment	114,178		108,262
Leasehold improvements	7,888		7,612
Property, Plant and Equipment Gross, Total	130,293		123,730
Less: accumulated depreciation and amortization	(95,348)		(85,608)
Property and equipment, net	34,945		38,122
Accrued liabilities:
Accrued compensation	6,688		10,890
Accrued incentive compensation	9,589		7,403
Accrued warranty	3,606		4,292
Other	15,466		19,830
Accrued liabilities, Total	$ 35,349		$ 42,415

[1] In the fourth quarter of 2013, the Company made a $7.5 million advance payment for future inventory requirements to a supplier in order to secure more favorable pricing from the supplier.