Warrants -Summary of Outstanding Warrants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	May. 11, 2015	Jan. 15, 2015	Dec. 31, 2014
Class Of Warrant Or Right [Line Items]
Number of Warrants	0
Convertible Note Warrants
Class Of Warrant Or Right [Line Items]
Exercise Price/Share	$ 14.00		$ 0.2189
Expiration Date	2022
Convertible Note Warrants | IPO
Class Of Warrant Or Right [Line Items]
Number of Warrants	144,772
Exercise Price/Share		$ 14.00
Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants				931
Exercise Price/Share	$ 6.45
Expiration Date	2019
Common Stock Warrants | IPO
Class Of Warrant Or Right [Line Items]
Number of Warrants	931
Series C-1 Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of Warrants				1,290,350
Exercise Price/Share	$ 37.16
Expiration Date	2016
Expiration Date	2017
Series C-2 Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of Warrants				157,912
Exercise Price/Share	$ 24.23
Expiration Date	2015
Series C-2 Redeemable Convertible Preferred Stock | IPO
Class Of Warrant Or Right [Line Items]
Exercise Price/Share		$ 24.23
Series D Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of Warrants	769,059			769,059
Exercise Price/Share	$ 1.07
Expiration Date	2020
Series E Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of Warrants				2,512,562
Exercise Price/Share	$ 23.51
Expiration Date	2024
Series E Redeemable Convertible Preferred Stock | IPO
Class Of Warrant Or Right [Line Items]
Number of Warrants	23,396