Stockholders’ equity (Details)	1 Months Ended	12 Months Ended
	Oct. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) Vote $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Nov. 12, 2020 USD ($)	Sep. 30, 2019 $ / shares
Common stock
Stock, shares authorized		440,000,000
Common stock, shares authorized		400,000,000	400,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.001	$ 0.001		$ 0.001
Preferred stock, shares authorized		40,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.001
Proceeds from issuance of common stock in initial public offering, net | $			$ 86,906,179
Common stock, shares outstanding		21,186,827	21,022,752
Number of voting rights per common share | Vote		1
Shelf Registration Statement
Maximum amount to be issued under universal shelf registration statement | $				$ 350,000,000
Maximum amount to be issued under at-the-market offering program | $				$ 50,000,000
Amount of equity or debt securities sold under at-the-market offering program | $		$ 0
IPO
Common stock
Number of shares issued	6,516,667
Issue price per share | $ / shares	$ 15.00
Proceeds from issuance of common stock in initial public offering, net | $	$ 86,600,000
Underwriters Option
Common stock
Number of shares issued	850,000