Convertible Preferred Stock Warrants (Details) - $ / shares	3 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Oct. 29, 2019	Oct. 25, 2019
IPO
Class of Warrant or Right [Line Items]
Share price (in dollars per share)			$ 13.00	$ 13
Exercise price (in dollars per share)				$ 1.73
Warrants to purchase common stock
Class of Warrant or Right [Line Items]
Warrants exercised (in shares)	482,661
Warrants to purchase convertible preferred stock
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	0	0
Warrants exercised, shares issued (in shares)	441,307
Warrants to purchase convertible preferred stock | Weighted Average
Class of Warrant or Right [Line Items]
Exercise price (in dollars per share)	$ 1.59