Organization and Operations (Details) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Oct. 07, 2016 USD ($) $ / shares shares	Oct. 07, 2016 $ / shares shares	Sep. 30, 2016	Dec. 31, 2016 USD ($) shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)
Organization And Operations
Reverse stock split ratio			0.038
Net proceeds from initial public offering | $				$ 33,864
Net proceeds from issuance of common stock in private placement | $				4,650
Accumulated deficit | $				(96,439)		$ (79,731)
Cash and Cash Equivalents, at Carrying Value | $				$ 29,727	$ 9,624	$ 2,307	$ 4,375
Convertible promissory notes payable
Organization And Operations
Conversion of convertible promissory notes (in shares) | shares		1,361,009
Initial Public Offering
Organization And Operations
Issuance of Series B redeemable convertible stock (in shares) | shares	5,000,000
Initial public offering price per share | $ / shares	$ 8.00	$ 8.00
Net proceeds from initial public offering | $	$ 33,900
Private Placement
Organization And Operations
Issuance of Series B redeemable convertible stock (in shares) | shares	625,000
Net proceeds from issuance of common stock in private placement | $	$ 4,700
Redeemable Convertible Preferred Stock
Organization And Operations
Issuance of Series B redeemable convertible stock (in shares) | shares					385,641
Conversion of redeemable convertible preferred stock to common stock (in shares) | shares		2,486,199		(2,486,199)
Conversion of convertible promissory notes (in shares) | shares					77,518