Note 4 - Stock-based Compensation - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions |
3 Months Ended | |
---|---|---|
Mar. 31, 2022 |
Mar. 31, 2021 |
|
Intrinsic value of stock options exercised | $ 42 | $ 23 |
Cash received from option exercises | 15 | 30 |
Treasury shares repurchased for employee payroll taxes | (5) | (6) |
Tax benefit realized from option exercises | 5 | 4 |
Aggregate grant-date fair value of stock options vested | $ 13 | $ 14 |