RETIREMENT BENEFITS - Changes in Benefit Obligations and Plan Assets as Well as Funded Status of Retirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change in plan assets
Fair value of plan assets at beginning of year	$ 807,016
Fair value of plan assets at end of year	769,630	$ 807,016
Pension Benefits
Change in benefit obligation
Obligation at beginning of year	698,726	674,104
Service cost	8,415	8,573	$ 12,603
Interest cost	33,868	34,725	20,579
Actuarial (gains) losses	(18,748)	22,938
Special termination benefits	0	577
Plan amendments	0	(76)
Curtailment gain	(239)	0
Benefits paid	(62,056)	(45,006)
Participants’ contributions	0	0
Foreign currency exchange rate changes	(5,995)	2,891
Obligation at end of year	653,971	698,726	674,104
Change in plan assets
Fair value of plan assets at beginning of year	807,016	764,405
Actual return on plan assets	21,689	84,849
Employer contributions	2,981	2,768
Participants’ contributions	0	0
Benefits paid	(62,056)	(45,006)
Fair value of plan assets at end of year	769,630	807,016	764,405
Funded status	115,659	108,290
Amounts recognized in the consolidated balance sheets
Non-current assets	206,800	203,494
Current liabilities	(3,009)	(3,055)
Non-current liabilities	(88,132)	(92,149)
Net amount recognized	115,659	108,290
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss (gain)	170,649	176,877
Prior service cost (credit)	234	391
Net amount recognized	170,883	177,268
Other Postretirement Benefits
Change in benefit obligation
Obligation at beginning of year	13,373	14,447
Service cost	27	50	78
Interest cost	644	745	413
Actuarial (gains) losses	(65)	645
Special termination benefits	0	0
Plan amendments	(339)	0
Curtailment gain	0	(1,103)
Benefits paid	(1,703)	(1,430)
Participants’ contributions	18	19
Foreign currency exchange rate changes	0	0
Obligation at end of year	11,955	13,373	14,447
Change in plan assets
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	1,685	1,411
Participants’ contributions	18	19
Benefits paid	(1,703)	(1,430)
Fair value of plan assets at end of year	0	0	$ 0
Funded status	(11,955)	(13,373)
Amounts recognized in the consolidated balance sheets
Non-current assets	0	0
Current liabilities	(1,299)	(1,389)
Non-current liabilities	(10,656)	(11,984)
Net amount recognized	(11,955)	(13,373)
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss (gain)	(4,443)	(4,740)
Prior service cost (credit)	(340)	(21)
Net amount recognized	$ (4,783)	$ (4,761)