Stockholders' equity (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Shares of common stock authorized	400,000,000	200,000,000
Shares of common stock issued and outstanding	170,748,395	158,043,880
Shares of preferred stock authorized	100,000,000
Shares of preferred stock issued and outstanding	0
Number of "excess stock" authorized (in shares)	200,000,000
Number of excess stock authorized issued and outstanding (in shares)	0