Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - Redeemable - USD ($) $ in Thousands	Redeemable Convertible Preferred Stock	Total
Balance at Dec. 31, 2013	$ 52,599
Balance (in shares) at Dec. 31, 2013	2,023,040
Increase (Decrease) in Redeemable Convertible Preferred Stock
Issuance of Series B redeemable convertible stock	$ 10,027
Issuance of Series B redeemable convertible stock (in shares)	385,641
Conversion of convertible promissory notes	$ 2,016
Conversion of convertible promissory notes (in shares)	77,518
Balance at Dec. 31, 2014	$ 64,642
Balance (in shares) at Dec. 31, 2014	2,486,199
Balance at Dec. 31, 2015	$ 64,642	$ 64,642
Balance (in shares) at Dec. 31, 2015	2,486,199	2,486,199
Increase (Decrease) in Redeemable Convertible Preferred Stock
Conversion of redeemable convertible preferred stock to common stock	$ (64,642)	$ 64,642
Conversion of redeemable convertible preferred stock to common stock (in shares)	(2,486,199)
Conversion of convertible promissory notes		$ 8,634
Balance (in shares) at Dec. 31, 2016		0