Debt (Details) $ / shares in Units, $ in Thousands	1 Months Ended						12 Months Ended
	Jun. 30, 2016 USD ($)	Nov. 30, 2015 USD ($)	Oct. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($) item	Apr. 30, 2013 USD ($) $ / shares shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) item	Apr. 30, 2014 $ / shares	Dec. 31, 2007 $ / shares
Debt Instrument [Line Items]
Interest expense							$ 533	$ 3,505	$ 4,219
Royalty due							$ 1,800
Exercise price of warrants (in dollars per share) | $ / shares											$ 0.0978
Repayments of equipment financing								$ 5,850	$ 2,480
Secured Loan Arrangement
Debt Instrument [Line Items]
Repayments			$ 28,000
Effective interest rate (as a percent)							20.90%	19.80%
Number of shares of common stock that may be called by warrants | shares						376,691
Exercise price of warrants (in dollars per share) | $ / shares						$ 2.3229				$ 2.3229
Prepayment premium (as a percent)						10.00%
Amount paid to extinguish debt			28,000
Credit Agreement
Debt Instrument [Line Items]
Borrowing capacity						$ 40,000
Borrowings						$ 20,000
Base interest rate (as a percent)						1.00%
Spread on base interest rate (as a percent)						8.00%
Interest expense							$ 1,400	$ 1,800
Credit Agreement | Minimum
Debt Instrument [Line Items]
Interest rate (as a percent)						9.00%
Royalty Agreement
Debt Instrument [Line Items]
Royalty payment percentage owed on fiscal year revenues up to threshold						1.00%
Revenue threshold amount for determination of royalty payment percentage						$ 50,000
Royalty payment percentage owed on fiscal year revenues in excess of threshold						1.50%
Interest expense							7,100	2,200
Line Of Credit-UBS
Debt Instrument [Line Items]
Borrowing capacity				$ 50,000
Borrowings	$ 8,000	$ 10,000	$ 32,000
Repayments	1,000
Remaining borrowing capacity							400
Outstanding balance							49,600
Interest expense								$ 100
Effective interest rate (as a percent)		0.85%	0.84%
Accrued interest							$ 600
Amount paid to extinguish debt	$ 1,000
Line Of Credit-UBS | 30-day LIBOR
Debt Instrument [Line Items]
Spread on variable rate (as a percent)				0.65%
Equipment Financing Facility
Debt Instrument [Line Items]
Borrowing capacity						$ 5,000
Borrowings					$ 5,900
Effective interest rate (as a percent)					6.35%	7.35%			6.35%
Number of payment installments | item					30				30
Repayments of equipment financing				$ 4,100
Equipment Financing Facility | 30-day LIBOR
Debt Instrument [Line Items]
Spread on variable rate (as a percent)						2.50%
Equipment Financing Facility | Prime
Debt Instrument [Line Items]
Spread on variable rate (as a percent)					3.10%	4.10%