RETIREMENT BENEFITS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8,415	$ 8,573	$ 12,603
Interest cost	33,868	34,725	20,579
Expected return on plan assets	(43,085)	(40,781)	(69,132)
Amortization of prior service cost (credit)	90	97	222
Amortization of actuarial losses (gains)	7,917	11,638	4,635
Special termination benefits	0	577	0
Curtailment gain	(244)	0	0
Net periodic benefit cost (credit)	6,961	14,829	(31,093)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	27	50	78
Interest cost	644	745	413
Expected return on plan assets	0	0	0
Amortization of prior service cost (credit)	(20)	(948)	(1,668)
Amortization of actuarial losses (gains)	(361)	(617)	(298)
Special termination benefits	0	0	0
Curtailment gain	0	(1,103)	0
Net periodic benefit cost (credit)	$ 290	$ (1,873)	$ (1,475)