RETIREMENT BENEFITS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 12,603	$ 14,265	$ 13,638
Interest cost	20,579	17,697	23,074
Expected return on plan assets	(69,132)	(79,453)	(72,122)
Amortization of prior service cost (credit)	222	243	205
Amortization of actuarial losses (gains)	4,635	12,479	11,859
Net periodic benefit credit	(31,093)	(34,769)	(23,346)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	78	107	88
Interest cost	413	363	566
Expected return on plan assets	0	0	0
Amortization of prior service cost (credit)	(1,668)	(1,830)	(1,937)
Amortization of actuarial losses (gains)	(298)	(311)	(339)
Net periodic benefit credit	$ (1,475)	$ (1,671)	$ (1,622)