PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Detail) - Pension Plans Defined Benefit [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6,506	$ 6,471
Interest cost	6,534	6,219
Expected return on plan assets	(14,716)	(13,285)
Amortization of prior service cost	(63)	(25)
Amortization of unrecognized actuarial loss	3,906	3,581
Net postretirement benefit cost (income)	2,167	$ 2,961
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 50,000