Stockholders' equity - At-the-market offerings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	May 15, 2024
Class of Stock [Line Items]
Sale of stock, aggregate offering price, maximum			$ 350.0
Number of shares issued (in shares)	979,308	3,821,362
Proceeds from issuance of equity	$ 5.7	$ 12.6
Shares available for issuance under the plan (in shares)	$ 92.1	$ 97.8
At-The-Market Offering
Class of Stock [Line Items]
Sale of stock, aggregate offering price, maximum			$ 100.0
Number of shares issued (in shares)	2,992,547
Proceeds from issuance of equity	$ 10.4
New At-The-Market Offering
Class of Stock [Line Items]
Number of shares issued (in shares)	828,815
Proceeds from issuance of equity	$ 2.2