Accounts Receivable - Accounts receivable, net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accounts Receivable.
Billed	$ 271,515	$ 315,332
Unbilled	59,831	103,498
Other receivables	678	4,816
Total	332,024	423,646
Less: allowance for credit losses	(7,109)	(7,078)
Accounts receivable, net	$ 324,915	$ 416,568