SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Balances Related to Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 134,267	$ 117,400
Less accumulated depreciation	(92,422)	(101,364)
Property and equipment, net	41,845	16,026
Building and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,000	9,700
Equipment and Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	40,000	56,900
Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	39,800	4,100
Property and equipment, net	28,600	2,300
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 43,400	$ 46,700