Stockholders’ equity (deficit) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Vote $ / shares shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019 $ / shares shares	Sep. 30, 2019 $ / shares
Stockholders’ equity (deficit)
Aggregate number of authorized shares for all classes of equity	440,000,000		440,000,000
Common stock, authorized	400,000,000		400,000,000		400,000,000
Common stock, par value | $ / shares	$ 0.001		$ 0.001		$ 0.001	$ 0.001
Preferred stock, authorized	40,000,000		40,000,000
Preferred stock, par value | $ / shares	$ 0.001		$ 0.001
Number of voting rights per common share | Vote			1
Stock based compensation expense | $	$ 1,256,460	$ 186,963	$ 2,161,931	$ 284,909