Restricted cash (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Restricted Cash [Abstract]
Cash restricted under the terms of loan agreements	$ 299,634	$ 90,105
Collateral for letters of credit and performance bonds	39,322	40,384
Total restricted cash	$ 338,956	$ 130,489

Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.