Common stock and convertible preferred stock - Common Stock (Details)					6 Months Ended
	Apr. 28, 2021 USD ($) $ / shares item shares	Oct. 13, 2020 USD ($) $ / shares	Oct. 13, 2020 $ / shares shares	Oct. 06, 2020 $ / shares shares	Jun. 30, 2021 USD ($) Vote $ / shares shares	Apr. 26, 2021 $ / shares	Dec. 31, 2020 $ / shares shares	Jun. 30, 2020 $ / shares
Common stock voting right | Vote					1
Proceeds from issuance of common stock | $		$ 41,700,000			$ 906,000
Payments of underwriting discounts and commissions | $		$ 3,100,000
Common Stock, Par or Stated Value Per Share					$ 0.0001		$ 0.0001
Common Stock, Shares Authorized | shares					200,000,000		200,000,000
Fair value of common stock					$ 25.60	$ 28.70		$ 1.62
IPO And Over-Allotment Option
Stock issued | shares				3,737,500
IPO
Stock issued | shares				3,250,000
Share price				$ 12.00
Common Stock, Par or Stated Value Per Share				$ 0.0001
Common Stock, Shares Authorized | shares				200,000,000
Preferred Stock, Shares Authorized | shares				10,000,000
Preferred Stock, Par or Stated Value Per Share				$ 0.0001
Over-Allotment Option
Stock issued | shares			487,500
Share price		$ 12.00	$ 12.00
Private offering
Share price	$ 27.00
Proceeds from issuance of common stock | $	$ 27,000,000.0
Units Issued During Period, New Issues | shares	1,000,000
Number of share for company's common stock	1
Number of warrants | shares	1
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 45.00
Warrants and Rights Outstanding, Term	3 years
Fair Value of Warrants | $	$ 6,000,000.0
Volatility rate
Warrants and Rights Outstanding, Measurement Input	82.7
Risk-free interest rate
Warrants and Rights Outstanding, Measurement Input	0.35
Expected term (in years)
Warrants and Rights Outstanding, Measurement Input | $	3
Strike price (per share)
Warrants and Rights Outstanding, Measurement Input	45.00