Supplemental balance sheet and cash flow information (revenue in excess of billings) (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Revenue in excess of billings
Conditional right to receive consideration		$ 21,855	$ 20,680
Unconditional right to receive consideration	[1]	10,091	5,427
Revenue in excess of billings		$ 31,946	$ 26,107

[1] Represents revenues that are earned but not currently billable under the related contract terms.