Share-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Shares Subject to Outstanding Options
Options outstanding (in shares) | shares	1,789,303
Options granted (in shares) | shares	383,000
Options forfeited (in shares) | shares	(65,533)
Options exercised (in shares) | shares	0
Options outstanding (in shares) | shares	2,106,770
Weighted-Average Exercise Price Per Share
Options outstanding (in USD per share) | $ / shares	$ 3.89
Options granted (in USD per share) | $ / shares	0.47
Options forfeited (in USD per share) | $ / shares	2.71
Options exercised (in USD per share) | $ / shares	0.00
Options outstanding (in USD per share) | $ / shares	$ 3.30
Weighted- Average Remaining Contractual Term (in years)
Options outstanding	7 years 10 months 10 days
Aggregate Intrinsic Value
Options outstanding | $	$ 4