Share-based compensation - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Jun. 11, 2020	Jun. 07, 2018	Sep. 17, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share based compensation expense	$ 400,000	$ 400,000
Common stock reserved for issuance	4,791,834
Options granted	338,481	415,478
Stock option vesting period	2 years
Share-based compensation arrangement by share based payment award percentage of fair market Person holding more then 10% voting stock	110.00%
Intrinsic value of options outstanding	$ 13,200,000		$ 8,900,000
Intrinsic value of options unvested	400,000		$ 0.0
Intrinsic value of options exercised	$ 760,392	$ 49,050
Employee Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Option to purchase granted			463,754
Options vested			20,500
Minimum
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options outstanding	3 years
Maximum
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options outstanding	10 years
2014 Stock Incentive Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Common stock reserved for issuance						3,000,000
2018 Stock Incentive Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Common stock reserved for issuance					4,000,000
2020 Stock Incentive Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Common stock reserved for issuance				3,000,000
Stock Option Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options granted	338,482		484,254