Assets and Liabilities Measured at Fair Value - Assets And Liabilities Measured At Fair Value On A Recurring Basis (Details) - USD ($) $ in Millions |
Sep. 30, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Recurring | ||
| Assets and liabilities measured at fair value | ||
| Cash equivalents | $ 260 | $ 290 |
| Indemnification asset | 394 | 345 |
| Financial instrument assets | 92 | 23 |
| Debt | 1,983 | 1,750 |
| Recurring | Fair Value, Inputs, Level 1 [Member] | ||
| Assets and liabilities measured at fair value | ||
| Cash equivalents | 260 | 290 |
| Recurring | Significant Other Observable Inputs (Level 2) | ||
| Assets and liabilities measured at fair value | ||
| Indemnification asset | 394 | 345 |
| Financial instrument assets | 92 | 23 |
| Debt | $ 1,983 | $ 1,750 |
| 1.75% Exchangeable Senior Debentures due 2046 | ||
| Assets and liabilities measured at fair value | ||
| Interest rate (as a percent) | 1.75% |