Trade Accounts Receivable, Unbilled Services and Unearned Income - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Dec. 31, 2025 |
|
| Receivables [Abstract] | ||||
| Unbilled receivables (percentage) | 73.00% | 73.00% | 71.00% | |
| Contract assets (percentage) | 27.00% | 27.00% | 29.00% | |
| Increase in unbilled services | $ (42) | |||
| Decrease in unearned income | 195 | |||
| Net change in balance | (237) | |||
| Trade accounts receivable | $ 523 | $ 550 | $ 523 | |
| Cash proceeds from trade accounts | $ 519 | $ 546 | ||