Debt (Details) $ / shares in Units, $ in Thousands	1 Months Ended					12 Months Ended
	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, 2015 USD ($)	Dec. 31, 2014 USD ($) item	Dec. 31, 2013 USD ($)	Apr. 30, 2014 $ / shares	Dec. 31, 2007 $ / shares
Debt Instrument [Line Items]
Interest expense						$ 3,505	$ 4,219	$ 1,873
Royalty due						1,800
Exercise price of warrants (in dollars per share) | $ / shares										$ 0.0978
Prepayment penalty						7,313
Repayments of equipment financing						$ 5,850	$ 2,480	$ 475
Secured Loan Arrangement
Debt Instrument [Line Items]
Effective interest rate (as a percent)				19.80%		20.90%	19.80%	12.60%
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%			10.00%
Debt paid off		$ 20,000
Amount paid to extinguish debt		28,000
Prepayment penalty		2,000				$ (2,000)
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 rate floor (as a percent)					9.00%
Interest expense						1,400	$ 1,800	$ 1,300
Minimum liquidity required under debt covenants					$ 5,000
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		6,000				7,100	$ 2,200	$ 500
Prepayment penalty						$ (5,300)
Line Of Credit-UBS
Debt Instrument [Line Items]
Borrowing capacity			$ 50,000
Borrowings	$ 10,000	$ 32,000
Effective interest rate (as a percent)	0.85%	0.84%
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 reference rate (as a percent)					2.50%
Spread on variable rate (as a percent)					4.10%
Equipment Financing Facility | Prime
Debt Instrument [Line Items]
Spread on reference rate (as a percent)				3.10%