RESTRUCTURING - Schedule of Accrued Employee Severance and Related Benefit (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring Reserve [Roll Forward]
Costs incurred						$ 21,747	$ 21,743	$ 0
Employee severance and related benefits
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance				$ 18,573		18,573
Costs incurred		$ 17,236	$ 1,581		$ 21,743	18,721
Cash disbursements						(29,401)
Currency translation adjustments						202
Restructuring Reserve, Ending Balance	$ 8,095				$ 18,573	8,095	18,573
Office space reductions
Restructuring Reserve [Roll Forward]
Costs incurred	$ 1,497			$ 1,241		$ 3,000	$ 3,200