Common Stock (Details)		1 Months Ended	3 Months Ended
	Nov. 08, 2019 shares	Sep. 30, 2017 USD ($)	Mar. 31, 2020 USD ($) Vote shares	Dec. 31, 2019 shares
Common Stock
Common stock, shares authorized for issuance			290,000,000	290,000,000
Preferred stock, shares authorized for issuance			10,000,000	10,000,000
Number of votes per share of common stock | Vote			1
Dividends on common stock | $			$ 0
Shares of common stock reserved for issuance, on an as-converted basis
Shares reserved for exchange warrants			1,458,000	1,458,000
Shares available for future option grants			2,745,773	1,704,183
Outstanding options			5,719,820	5,643,410
Shares reserved for employee stock purchase plan			400,000	400,000
Total			10,323,593	9,205,593
Exchange Warrants
Shares of common stock reserved for issuance, on an as-converted basis
Exchange warrants	1,458,000		1,458,000
At-the-market offering | Cowen
Common Stock
Proceeds from sale of stock | $			$ 0
At-the-market offering | Cowen | Maximum
Common Stock
Potential gross proceeds | $		$ 50,000,000
Stock issuance costs, as a percent of gross proceeds		3.00%