Stockholders' equity - Schedule of Outstanding Warrants (Details) - $ / shares	Mar. 31, 2026	Feb. 11, 2026	Dec. 31, 2025
Class of Stock [Line Items]
Warrant outstanding (in shares)	40,970,657		58,420,290
Private Placement Offering Warrants
Class of Stock [Line Items]
Exercise price (in dollars per share)	$ 1.068	$ 1.0680	$ 1.068
Exercise period	5 years		5 years
Warrant outstanding (in shares)	36,808,240		46,816,480
Number of securities called by each warrant (in shares)	0.1
2025 3-Year Warrants
Class of Stock [Line Items]
Exercise price (in dollars per share)	$ 4.200		$ 4.200
Exercise period	3 years		3 years
Warrant outstanding (in shares)	4,162,417		4,823,900
2025 2-Year Warrants
Class of Stock [Line Items]
Exercise price (in dollars per share)	$ 6.000		$ 6.000
Exercise period	2 years		2 years
Warrant outstanding (in shares)	0		6,779,910