EMPLOYEE BENEFITS - Schedule of Assumptions used To Calculate Pension and SERP and PBOP (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return	7.00%	7.00%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return	8.25%	8.25%	8.25%
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return	8.25%	8.25%	8.25%
Minimum | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	1.50%	2.60%	2.70%
Compensation/Progression Rate	3.50%	3.50%	3.50%
Minimum | Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	1.80%	2.70%	3.90%
Maximum | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	3.00%	3.50%	3.60%
Compensation/Progression Rate	4.00%	4.00%
Maximum | Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	3.10%	3.60%	4.60%