EMPLOYEE BENEFITS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Expected long term return on plan assets	6.20%
Period of notice for quarterly redemption of diversified hedge	60 days
Employer contributions	$ 90.1	$ 5.2	$ 19.4
Defined benefit plan, costs recognized	$ 23.4	22.5	$ 19.9
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
U.S. pension plan allocation weight	88.00%
U.S. pension plan, estimated future contributions	$ 15.0
Employer contributions	$ 89.6	4.8
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
U.S. pension plan allocation weight	73.00%
Employer contributions	$ 0.5	$ 0.4
US GAAP Equity Securities | United States Pension Plan of US Entity
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, target plan asset allocations	50.00%
US GAAP Debt Securities | United States Pension Plan of US Entity
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, target plan asset allocations	50.00%