Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Series C Convertible Preferred Stock 2014 Convertible Promissory Notes	Private Placement	Convertible Preferred Stock	Convertible Preferred Stock Series C Convertible Preferred Stock	Convertible Preferred Stock Series C Convertible Preferred Stock 2014 Convertible Promissory Notes	Common Stock	Common Stock Private Placement	Common Stock Holders of Mirax	Additional Paid-in Capital	Additional Paid-in Capital Private Placement	Accumulated Deficit
Temporary equity balance at Dec. 31, 2013				$ 130,037
Temporary equity balance , shares at Dec. 31, 2013				25,036,330
Balance at Dec. 31, 2013	$ (117,150)						$ 9			$ 1,096		$ (118,255)
Balance, shares at Dec. 31, 2013							878,717
Issuance of common stock from option exercises	$ 21									21
Issuance of common stock from option exercises, shares	28,320						28,320
Repurchase of Series A convertible preferred stock and deemed capital contribution	$ 9			$ (25)								9
Repurchase of Series A convertible preferred stock and deemed capital contribution, shares				(1,353)
Issuance of convertible preferred stock					$ 4,969
Issuance of convertible preferred stock, shares					880,546
Conversion of convertible securities, value						$ 10,129
Conversion of convertible securities, shares		1,739,405				1,739,405
Stock-based compensation	297									297
Net loss	(33,800)											(33,800)
Temporary equity balance at Dec. 31, 2014				$ 145,110
Temporary equity balance , shares at Dec. 31, 2014				27,654,928
Balance at Dec. 31, 2014				$ 145,110			$ 9			1,414		(152,046)
Balance, shares at Dec. 31, 2014							907,037
Issuance of common stock from option exercises	$ 24									24
Issuance of common stock from option exercises, shares	31,427						31,427
Issuance of convertible preferred stock					$ 15,729
Issuance of convertible preferred stock, shares					2,727,059
Conversion of convertible securities, value	$ 160,839			$ (160,839)			$ 304			160,535
Conversion of convertible securities, shares				(30,381,987)			30,381,987
Stock-based compensation	1,066									1,066
Issuance of common stock value private placement			$ 26,323					$ 59			$ 26,264
Issuance stock								5,884,504	1,000,005
Conversion of convertible preferred stock warrants into common stock warrants in connection with the Merger	93									93
Issuance of common stock warrants to placement agent as payment for services	316									316
Net loss	(44,995)											(44,995)
Balance at Dec. 31, 2015	(6,957)						$ 372			189,712		(197,041)
Balance, shares at Dec. 31, 2015							38,204,960
Issuance of common stock from option exercises	$ 539						$ 8			531
Issuance of common stock from option exercises, shares	773,718						773,718
Stock-based compensation	$ 2,907									2,907
Issuance of common stock value private placement			$ 10,494					$ 46			$ 10,448
Issuance stock								4,602,506
Conversion of convertible preferred stock warrants into common stock warrants in connection with the Merger	93
Net loss	(50,636)											(50,636)
Balance at Dec. 31, 2016	$ (43,653)						$ 426			$ 203,598		$ (247,677)
Balance, shares at Dec. 31, 2016							43,581,184