Note 4 - Stock-based Compensation - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2024 |
Sep. 30, 2023 |
Sep. 30, 2024 |
Sep. 30, 2023 |
|
| Intrinsic value of stock options exercised | $ 15 | $ 10 | $ 31 | $ 17 |
| Cash received from option exercises | 16 | 9 | 40 | 17 |
| Treasury shares repurchased for employee payroll taxes | (2) | (1) | (7) | (3) |
| Income tax benefit realized from option exercises | 2 | 2 | 6 | 4 |
| Aggregate grant-date fair value of stock options vested | $ 0 | $ 0 | $ 15 | $ 14 |