Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) - Schedule of Unbilled Services and Unearned Revenue or Payments on Account (Details) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2024 |
Dec. 31, 2023 |
|
| Revenue from Contract with Customer [Abstract] | ||
| Unbilled services (unbilled revenue) | $ 1,230,948 | $ 951,936 |
| Change in unbilled services (unbilled revenue) | $ 279,012 | |
| Percentage change in unbilled services (unbilled revenue) | 29.30% | |
| Unearned revenue (payments on account) | $ (1,602,526) | (1,654,507) |
| Change in unearned revenue (payments on account) | $ 51,981 | |
| Percentage change in unearned revenue (payments on account) | (3.10%) | |
| Net balance | $ (371,578) | $ (702,571) |
| Change in net balance | $ 330,993 | |
| Percentage change in net balance | (47.10%) |