Stockholders' Equity - Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2015
Class Of Stock [Line Items]
Shares Authorized	10,000,000	0
Shares Issued	0	0
Shares Outstanding	0	0
Net Carrying Value
Convertible Preferred Stock, Series Seed
Class Of Stock [Line Items]
Shares Authorized	0	1,400,000
Original Issue Price per Share		$ 2.2300
Shares Issued	0	627,867
Shares Outstanding	0	627,867
Net Carrying Value		$ 1,378
Aggregate Liquidation Preference	$ 0	$ 1,400
Convertible Preferred Stock, Series A
Class Of Stock [Line Items]
Shares Authorized	0	11,199,876
Original Issue Price per Share		$ 5.9727
Shares Issued	0	5,022,876
Shares Outstanding	0	5,022,876
Net Carrying Value		$ 28,757
Aggregate Liquidation Preference	$ 0	$ 30,000
Convertible Preferred Stock, Series B
Class Of Stock [Line Items]
Shares Authorized	0	8,570,366
Original Issue Price per Share		$ 11.1942
Shares Issued	0	3,843,604
Shares Outstanding	0	3,843,604
Net Carrying Value		$ 42,835
Aggregate Liquidation Preference	$ 0	$ 43,026
Convertible Preferred Stock, Series C
Class Of Stock [Line Items]
Shares Authorized	0	9,684,789
Original Issue Price per Share		$ 15.0256	$ 15.0256
Shares Issued	0	4,325,954	4,325,954
Shares Outstanding	0	4,325,954
Net Carrying Value		$ 62,780
Aggregate Liquidation Preference	$ 0	$ 65,000
Convertible Preferred Stock
Class Of Stock [Line Items]
Shares Authorized		30,855,031
Shares Issued		13,820,301
Shares Outstanding		13,820,301
Net Carrying Value		$ 135,750
Aggregate Liquidation Preference		$ 139,426