Warrants -Summary of Outstanding Warrants (Details) - $ / shares	6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	May 11, 2015	Jan. 15, 2015	Aug. 22, 2014
Convertible Note Warrants
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants	144,772
Exercise Price/Share	$ 14.00				$ 0.2189
Expiration Date	2022
Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants	931
Exercise Price/Share	$ 6.45
Expiration Date	2019
Common Stock Warrants one
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants	45,307
Exercise Price/Share	$ 2.76	$ 2.759
Expiration Date	2026
IPO | Convertible Note Warrants
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants			144,772
Exercise Price/Share				$ 14.00
IPO | Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants			931
Series E Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants	28,713
Exercise Price/Share	$ 23.51	$ 23.51		$ 23.51		$ 0.2189
Expiration Date	2024
Series E Redeemable Convertible Preferred Stock | IPO
Class Of Warrant Or Right [Line Items]
Shares of Common Stock Underlying Warrants			23,396