Convertible Preferred Stock (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 30, 2013	Feb. 23, 2011	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Permanent And Temporary Equity [Line Items]
Conversion of convertible preferred stock to common stock, shares	12,120,531
Preferred stock, shares authorized			0	0
Accretion amount			$ 0	$ 0	$ 210
Accretion amount			$ 0	$ 0	240
Convertible preferred stock series B
Permanent And Temporary Equity [Line Items]
Issuance of convertible preferred stock		$ 23,800
Stock issuance costs		1,200
Convertible Preferred Stock
Permanent And Temporary Equity [Line Items]
Accretion amount					210
Convertible preferred stock series A-4
Permanent And Temporary Equity [Line Items]
Difference between stated and fair value		$ 1,300
Accretion amount					$ 240