Convertible Preferred Stock (Details) $ / shares in Units, $ in Thousands			1 Months Ended	9 Months Ended
	Jun. 30, 2015 $ / shares shares	Mar. 13, 2015 USD ($) $ / shares shares	Jun. 30, 2015 $ / shares shares	Sep. 30, 2016 $ / shares shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 $ / shares shares
Preferred Stock, Number of Shares, Par Value and Other Disclosures
Preferred Stock, Shares Authorized				5,000,000		5,000,000
Preferred Stock, Par or Stated Value Per Share | $ / shares				$ 0.001		$ 0.001
Preferred Stock, Shares Issued				0		0
Proceeds from issuance of preferred stock, net of issuance costs | $					$ 12,331
Preferred stock, outstanding				0		0
Minimum number of series used to issue preferred stock				1
Initial public offering
Preferred Stock, Number of Shares, Par Value and Other Disclosures
Share price (in dollars per share) | $ / shares	$ 12.00		$ 12.00
Conversion of convertible preferred stock into common stock (in shares)	9,029,549		9,029,549
Series B Convertible Preferred Stock
Preferred Stock, Number of Shares, Par Value and Other Disclosures
Preferred Stock, Shares Authorized		56,026,590
Preferred Stock, Shares Issued		13,062,965
Share price (in dollars per share) | $ / shares		$ 0.9503
Proceeds from issuance of preferred stock, net of issuance costs | $		$ 12,300