PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 8,250	$ 10,965	$ 16,511	$ 21,822
Expected return on plan assets	(15,544)	(13,905)	(31,185)	(27,799)
Amortization of prior service cost	43	27	86	55
Recognized net actuarial (gain) loss	0	862	0	1,260
Benefit plans, net	(7,251)	(2,051)	(14,588)	(4,662)
Service cost included in COS	209	150	420	300
Net periodic benefit cost (benefit)	(7,042)	(1,901)	(14,168)	(4,362)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	72	119	144	239
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(271)	(539)	(542)	(1,078)
Recognized net actuarial (gain) loss	0	0	0	0
Benefit plans, net	(199)	(420)	(398)	(839)
Service cost included in COS	4	4	9	8
Net periodic benefit cost (benefit)	$ (195)	$ (416)	$ (389)	$ (831)