Stock-based Compensation - Schedule Options to Purchase Common Stock (Details) - 2019 Plan - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Number of Shares
Number of shares, options outstanding, beginning balance (in shares)	731,189
Granted (in shares)	1,766,381
Cancelled (in shares)	(799)
Number of shares, options outstanding, ending balance (in shares)	2,496,771	731,189
Options exercisable (in shares)	416,464
Weighted Average Exercise Price
Beginning balance, weighted average exercise price (in USD per share)	$ 4.59
Weighted average exercise price, granted (in USD per share)	0.51
Weighted average exercise price, cancelled (in USD per share)	7.56
Ending balance, weighted average exercise price (in USD per share)	1.70	$ 4.59
Weighted average exercise price, options exercisable (in USD per share)	$ 5.00
Additional Disclosures
Beginning balance, weighted average remaining contractual life	9 years 2 months 12 days	8 years
Weighted average remaining contractual life, options exercisable	6 years 8 months 12 days
Aggregate intrinsic value, beginning balance	$ 24,028
Aggregate intrinsic value, ending balance	23	$ 24,028
Aggregate intrinsic value, options exercisable	$ 0