Note 3 - Stock-based Compensation - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2023 |
Sep. 30, 2022 |
Sep. 30, 2023 |
Sep. 30, 2022 |
|
| Intrinsic value of stock options exercised | $ 10 | $ 7 | $ 17 | $ 51 |
| Cash received from option exercises | 9 | 7 | 17 | 24 |
| Treasury shares repurchased for employee payroll taxes | (1) | (2) | (3) | (7) |
| Income tax benefit realized from option exercises | 2 | 1 | 4 | 7 |
| Aggregate grant-date fair value of stock options vested | $ 0 | $ 0 | $ 14 | $ 13 |