EMPLOYEE BENEFITS (Allocation of invested defined benefit pension plan assets) (Details)	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Percentage of defined benefit pension plan assets	100.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Percentage of defined benefit pension plan assets	40.00%
Equities
Defined Benefit Plan Disclosure [Line Items]
Percentage of defined benefit pension plan assets	55.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Percentage of defined benefit pension plan assets	5.00%