Stockholders' equity - Equity Classified Warrants (Details) $ / shares in Units, $ in Millions								1 Months Ended	12 Months Ended
	Dec. 03, 2025 USD ($) shares	Sep. 02, 2025 USD ($) $ / shares shares	Nov. 14, 2023	Mar. 15, 2022 USD ($)	Mar. 14, 2022 USD ($) $ / shares shares	Oct. 06, 2020 USD ($) $ / shares shares	May 29, 2020 $ / shares shares	Jun. 30, 2025 USD ($) shares	Dec. 31, 2025 $ / shares shares	Dec. 31, 2024 $ / shares shares	Dec. 31, 2020 $ / shares shares	Dec. 14, 2025 $ / shares	Oct. 05, 2025 shares	Jul. 11, 2025	Jun. 12, 2025 $ / shares	May 28, 2025 shares
Class of Warrant or Right [Line Items]
Split conversion ratio			0.1								0.1
Outstanding warrants (in shares)									58,420,290	90,019,112
Stock price (in dollars per share) | $ / shares															$ 3.40
Warrants and rights outstanding, term (in years)									36 months
Number of shares issued (in shares)									979,308	3,821,362
Warrants, expected term				5 years
Risk-free interest rate (in percent)				2.10%
Expected volatility (in percent)				118.40%
Warrants issued (in shares)									14,196,028
Private Placement
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, term (in years)					5 years
Number of shares issued (in shares)					46,816,480
Consideration received, net of issuance costs | $					$ 55.9
Proceeds from private placement and forward purchase contract | $				$ 55.9
2025 Private Placement Of Common Stock And 2-Year Warrants
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, term (in years)		2 years
Number of shares issued (in shares)		14,017,056
Consideration received, net of issuance costs | $		$ 60.0
5-Year Public Warrants
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares							$ 11.50			$ 11.500	$ 11.50
Outstanding warrants (in shares)									0	33,619,298						33,619,298
Number of securities called by each warrant (in shares)							0.1		0.1		0.1
Warrants and rights outstanding, term (in years)							5 years			5 years
Units issued (in shares)							20,800,000
Number of warrants called by each unit (in shares)							1
Number of securities called by warrants (in shares)							3,249,999
Warrants issued (in shares)									0
Public Offering Warrants (5-Year)
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares						$ 10.50				$ 10.500	$ 10.50
Outstanding warrants (in shares)									0	9,583,334			9,583,334
Proceeds from issuance of warrants | $						$ 83.1
Number of securities called by each warrant (in shares)						0.1					0.1
Warrants and rights outstanding, term (in years)						5 years				5 years
Units issued (in shares)						9,583,334
Number of warrants called by each unit (in shares)						1
Units issued, offering price (in dollars per share) | $ / shares						$ 9.00
Units issued, related party (in shares)						5,000,000.0
Warrants issued (in shares)									0
2025 3-Year Warrants
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares									$ 4.200			$ 4.20
Outstanding warrants (in shares)								7,187,500	4,823,900
Proceeds from issuance of warrants | $								$ 5.9
Number of securities called by each warrant (in shares)		1							1
Warrants and rights outstanding, term (in years)									3 years					3 years
Warrants issued (in shares)									7,187,500
2025 3-Year Warrants | Measurement Input, Risk Free Interest Rate
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input									0.0416
2025 3-Year Warrants | Measurement Input, Price Volatility
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input									0.5500
2025 3-Year Warrants | Measurement Input, Exercise Price | 2025 Private Placement
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input | $ / shares									4.20
2025 2-Year Warrants
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares		$ 6.00							$ 6.000
Outstanding warrants (in shares)		7,008,528							6,779,910
Proceeds from issuance of warrants | $		$ 2.8
Number of securities called by each warrant (in shares)		1
Stock price (in dollars per share) | $ / shares									$ 5.80
Warrants and rights outstanding, term (in years)									2 years
Class of warrant or right, trigger for required exercise, minimum volume weighted average stock price (in USD per share) | $ / shares									$ 8.00
Warrant, trigger for required exercise, minimum trading day period		20 days
Warrant, trigger for required exercise, maximum trading day threshold		30 days
Warrants issued (in shares)									7,008,528
2025 2-Year Warrants | 2025 Private Placement
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares												6.00
Outstanding warrants (in shares)	116,809
Proceeds from issuance of warrants | $	$ 0.7
Class of warrant or right, trigger for required exercise, minimum volume weighted average stock price (in USD per share) | $ / shares		$ 8.00
Warrant, trigger for required exercise, minimum trading day period		20 days
Warrant, trigger for required exercise, maximum trading day threshold		30 days
2025 2-Year Warrants | Measurement Input, Risk Free Interest Rate
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input									0.0380
2025 2-Year Warrants | Measurement Input, Price Volatility
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input									0.5500
2025 2-Year Warrants | Measurement Input, Exercise Price
Class of Warrant or Right [Line Items]
Warrants and rights outstanding, measurement input | $ / shares									6.00
Private Placement Offering Warrants
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares									$ 1.068	$ 1.068		$ 6.00
Outstanding warrants (in shares)									46,816,480	46,816,480
Number of securities called by each warrant (in shares)									0.1
Warrants and rights outstanding, term (in years)									5 years	5 years
Warrants issued (in shares)									0
Private Placement Offering Warrants | Private Placement
Class of Warrant or Right [Line Items]
Warrants, exercise price (in USD per share) | $ / shares					$ 1.068