POSTRETIREMENT BENEFITS (Details 5) - Other Postretirement Benefit Plans, Defined Benefit |
12 Months Ended | |
|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Assumed healthcare cost trend rates [Abstract] | ||
| Healthcare cost trend rate assumed for next year | 7.50% | 7.50% |
| Rate that the cost trend rate gradually declines to | 4.50% | 4.50% |
| Year that the rate reaches the ultimate rate | 2031 | 2024 |