PENSION AND OTHER POSTRETIREMENT PLANS - Schedule of Assumptions Used in Calculating the Net Benefit Obligation (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	2.98%	4.08%	3.46%
Lump sum assumed interest rates for First 5 years	2.01%	3.33%	2.05%
Lump sum assumed interest rates for Next 15 years	3.06%	4.39%	3.61%
Lump sum assumed interest rates for All future years	3.65%	4.72%	4.27%
Net pension expense, Weighted average discount rate	4.08%	3.46%	3.86%
Expected long-term rate of return	6.50%	6.50%	6.50%
SERP Benefits
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	2.98%	4.08%	3.46%
Net pension expense, Weighted average discount rate	4.08%	3.46%	3.86%
Expected long-term rate of return	6.50%	6.50%	6.50%