EMPLOYEE BENEFIT PLANS (Target Allocation Percentages for Major Categories of Plan Assets) (Details)	Dec. 31, 2017
Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	100.00%
Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	100.00%
Cash/Treasury Bills | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	0.00%
Cash/Treasury Bills | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	2.00%
United States Large Cap | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	16.00%
United States Large Cap | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	39.00%
United States Small Cap | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	5.00%
United States Small Cap | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	5.00%
Non-United States Developed | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	14.00%
Non-United States Developed | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	7.00%
Non-United States Emerging | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	4.00%
Non-United States Emerging | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	9.00%
Global Equity | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	4.00%
Global Equity | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	0.00%
Global Infrastructure | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	3.00%
Global Infrastructure | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	0.00%
Fixed Income Securities | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	45.00%
Fixed Income Securities | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	38.00%
Real Estate | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	8.00%
Real Estate | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	0.00%
Private Equity | Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	1.00%
Private Equity | Other Postretirement Benefits
Pension And Other Employee Benefit Plans [Line Items]
Target allocation percentage of plan assets (in percentage)	0.00%