LEASE COST (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lease Cost Table Line Items
Total lease cost	$ 59,243	$ 64,088
Depreciation and Amortization
Lease Cost Table Line Items
Amortization of ROU assets - finance leases	6,674	7,661
Interest Expense
Lease Cost Table Line Items
Interest on lease liabilities - finance leases	136	203
Cost of Services
Lease Cost Table Line Items
Operating lease cost (cost resulting from lease payments)	39,087	46,375
Short-term Lease, Cost	4,529	3,888
Variable Lease, Cost	(1,246)
Variable Lease, Cost		(287)
Selling General And Administrative Expenses [Member]
Lease Cost Table Line Items
Operating lease cost (cost resulting from lease payments)	2,770	2,040
Sublease Income	(807)	(836)
Restructuring
Lease Cost Table Line Items
Operating lease cost (cost resulting from lease payments)	1,614	1,232
Impairment
Lease Cost Table Line Items
Operating lease cost (cost resulting from lease payments)	5,338	5,127
Other income (expense), net
Lease Cost Table Line Items
Operating lease cost (cost resulting from lease payments)	1,240	1,149
Sublease Income	$ (2,584)	$ (2,464)