PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Additional) (Detail) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Cost	$ 7.4	$ 6.8
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 10.8
Scenario, Forecast [Member]
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Discretionary Contribution Amount			$ 14.0