EMPLOYEE BENEFIT PLANS - Net Periodic Pension Cost (Credit) (Details) - U.K. Plan - Pension Plan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 443	$ 561	$ 1,310	$ 1,740
Expected return on plan assets	(580)	(574)	(1,715)	(1,781)
Amortization of prior service cost	8	8	24	24
Net periodic pension credit	$ (129)	$ (5)	$ (381)	$ (17)