Equity Incentive Plans - Schedule of Stock Option Plan Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Shares Available for Grant, Beginning balance	7,255,050
Options Outstanding, Shares Available for Grant, Authorized	3,182,868
Options Outstanding, Shares Available for Grant, RSUs forfeited, net of grants	297,155
Options Outstanding, Shares Available for Grant, Granted	(5,140,100)
Options Outstanding, Shares Available for Grant, Canceled	3,156,463
Options Outstanding, Shares Available for Grant, Ending balance	8,751,436	7,255,050
Options Outstanding, Number of Options, Beginning balance	8,986,010
Options Outstanding, Number of Options, Granted	5,140,100
Options Outstanding, Number of Options, Exercised	(548,523)
Options Outstanding, Number of Options, Canceled	(3,280,143)
Options Outstanding, Number of Options, Ending balance	10,297,444	8,986,010
Options Outstanding, Number Options, Options exercisable	5,702,112
Options Outstanding, Number of Options, Options vested and expected to vest	9,492,970
Options Outstanding, Weighted-Average Exercise Price, Beginning balance	$ 7.54
Options Outstanding, Weighted-Average Exercise Price, Granted	3.55
Options Outstanding, Weighted-Average Exercise Price, Exercised	0.97
Options Outstanding, Weighted-Average Exercise Price, Canceled	8.80
Options Outstanding, Weighted-Average Exercise Price, Ending balance	5.49	$ 7.54
Options Outstanding, Weighted-Average Exercise Price, Options exercisable	6.59
Options Outstanding, Weighted-Average Exercise Price, Options vested and expected to vest	$ 5.63
Options Outstanding, Aggregate Intrinsic Value, Balance	$ 680	$ 5,458
Options Outstanding, Aggregate Intrinsic Value, Options exercisable-December 31, 2019	670
Options Outstanding, Aggregate Intrinsic Value, Options vested and expected to vest-December 31, 2019	$ 678