Organization and Nature of Business - IPO, Stock Split, Liquidity (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Oct. 13, 2015 USD ($) $ / shares shares	Sep. 24, 2015	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Initial public offering
Aggregate gross proceeds			$ 56,550
Common stock shares issued upon conversion of convertible preferred stock | shares	11,677,076
Payments of initial public offering costs			2,272
Reverse stock split		0.2899
Accumulated deficit			42,833	$ 20,749
Cash, cash equivalents and marketable securities			92,038
Proceeds from initial public offering, net of offering costs			$ 56,550
IPO
Initial public offering
Number of shares issued in offering | shares	5,000,000
Issuance price (in dollars per share) | $ / shares	$ 11.00
Aggregate gross proceeds	$ 55,000
Payments of initial public offering costs	2,272
Offering proceeds, net of discounts, commissions and expenses	$ 56,550
Exercise of over-allotment option
Initial public offering
Number of shares issued in offering | shares	750,000
Issuance price (in dollars per share) | $ / shares	$ 11.00
Aggregate gross proceeds	$ 8,250
Payments of initial public offering costs	$ 4,428