BENEFIT PLANS - FAIR VALUES OF PENSION PLAN ASSETS (Details)	Dec. 31, 2015
Mutual funds | Equity
Schedule of Pension and Other Postretirment Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Percentage of investments	50.00%
Mutual funds | Fixed Income Investments
Schedule of Pension and Other Postretirment Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Percentage of investments	50.00%
Common trusts | Equity
Schedule of Pension and Other Postretirment Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Percentage of investments	65.00%
Common trusts | Fixed Income Investments
Schedule of Pension and Other Postretirment Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items]
Percentage of investments	35.00%