Stockholders' Equity - Equity offerings (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Dec. 31, 2019	Nov. 30, 2019	Mar. 31, 2020	Mar. 31, 2019
Class of Warrant or Right [Line Items]
Public offering price		$ 13.61
Variation between public offering prices of common stock and pre-funded warrants		$ 0.0001
Net proceeds from sale of stock	$ 85,598
Issuance costs and underwriter fees			$ 355	$ 2,157
Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants		2,200,000
Pre-funded warrants exercise price		$ 13.6099
Maximum percentage of holding for exercise warrants		9.99%
Prior notice period to change percentage of holding		61 days
Underwriter rights
Class of Warrant or Right [Line Items]
Common stock sold	838,530	3,678,031
Number of days for purchase shares		30 days
Maximum additional shares to purchase		881,704
Issuance costs and underwriter fees	$ 5,814