Common Stock (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Common stock dividend	$ 0
Common stock reserved for future issuance	3,046,784	12,826,886
Stock incentive awards
Class of Stock [Line Items]
Common stock reserved for future issuance	819,451	100,034
Stock options to purchase common stock
Class of Stock [Line Items]
Common stock reserved for future issuance	2,113,538	1,569,379
Stock warrants to purchase common stock
Class of Stock [Line Items]
Common stock reserved for future issuance	113,795	651,618
Series A redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		664,068
Series B redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		1,907,006
Series C redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		1,282,051
Series D redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		2,191,412
Series SRN redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		1,798,433
Series E redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance		2,662,885