PENSION AND OTHER POST-EMPLOYMENT BENEFITS - Weighted-Average Asset Allocations (Details) - Pension Benefits	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocation	100.00%	100.00%
Temporary investment funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocation	3.00%	1.00%
Equity investment funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocation	35.00%	41.00%
Fixed income funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocation	62.00%	58.00%