Income Taxes - Schedule of Deferred Tax Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Net operating losses	$ 61,739	$ 38,357
Capitalized research and development	8,903	7,901
Accrued expenses	3,707	3,728
Research and development credits	1,237	1,078
Accrued product returns	1,087	916
Inventory reserve and UNICAP	688	983
Depreciation and amortization	645	824
Deferred revenue	0	3,169
Other, net	2,341	1,403
Total deferred tax assets	80,347	58,359
Less valuation allowance	(80,347)	(58,359)
Net deferred tax assets	$ 0	$ 0