v3.26.1
Income taxes - Cash paid for income taxes, net of refunds received (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2025
USD ($)
Income taxes  
Subtotal $ 15
Total $ 15
Income Tax Paid, after Refund Received, Foreign Jurisdiction [Extensible Enumeration] Foreign Tax Jurisdiction, Other [Member]
Effective Income Tax Rate Reconciliation, State and Local Jurisdiction, Contribution Greater than 50 Percent, Tax Effect [Extensible Enumeration] Massachusetts
Massachusetts  
Income taxes  
U.S. state and local $ 13
California  
Income taxes  
U.S. state and local 1
Other  
Income taxes  
U.S. state and local $ 1