Debt (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended		9 Months Ended
	Jun. 30, 2016	Nov. 30, 2015	Oct. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Borrowings						$ 8,000
Repayments						1,000
Interest expense				$ 146	$ 1,177	383	$ 3,391
Amount paid to extinguish debt						$ 1,000
Repayments of equipment financing							5,850
Secured Loan Arrangement
Debt Instrument [Line Items]
Exercise price of warrants (in dollars per share)				$ 2.3229		$ 2.3229
Line Of Credit-UBS
Debt Instrument [Line Items]
Borrowing capacity					$ 50,000		$ 50,000
Borrowings	$ 8,000		$ 32,000
Repayments	1,000
Remaining borrowing capacity	700
Effective interest rate (as a percent)				1.10%		1.10%
Accrued interest	300
Amount paid to extinguish debt	$ 1,000
Line Of Credit-UBS | 30-day LIBOR
Debt Instrument [Line Items]
Borrowings		$ 10,000
Spread on variable rate (as a percent)				0.65%		0.65%
Principal balance		$ 42,000