EMPLOYEE BENEFIT PLANS - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Stock-based compensation expense by type: | |||
| Restricted stock | $ 152 | $ 124 | $ 145 |
| Stock options | 11 | 13 | 12 |
| Total stock-based compensation expense | 163 | 137 | 157 |
| Tax benefit recognized | (35) | (21) | (32) |
| Stock-based compensation expense, net of tax | $ 128 | $ 116 | $ 125 |