Summary of Significant Accounting Policies - Schedule of Change in Fair Value of Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Redeemable convertible preferred stock warrant
Reclassification to additional paid-in capital	$ 65
Redeemable Convertible Preferred Stock Warrants | Level 3
Redeemable convertible preferred stock warrant
Beginning balance	437	$ 145
Issuance of redeemable convertible preferred stock warrants		307
Change in fair value recorded in other income, net	(372)	(15)
Reclassification to additional paid-in capital	$ (65)
Ending balance		$ 437