IMPACT OF THE INVASION OF UKRAINE (Narrative) (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Mar. 04, 2022
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	$ 239,654,000			$ 239,654,000		$ 273,348,000
Operating lease, right-of-use asset	136,311,000			136,311,000		148,780,000
Commitments related to operating lease agreements that have not yet commenced	12,300,000			12,300,000
Impairment charges				688,000	$ 21,212,000
Bad debt expense				2,739,000	12,888,000
Discontinued Operations, Disposed of by Sale
Unusual or Infrequent Item, or Both [Line Items]
Loss on sale of holdings	25,900,000
Humanitarian Commitment
Unusual or Infrequent Item, or Both [Line Items]
Commitments related to operating lease agreements that have not yet commenced	41,600,000			41,600,000
Nonoperating expense	3,600,000	$ 4,500,000		13,600,000	38,500,000
Humanitarian Commitment | Cost of revenues (exclusive of depreciation and amortization)
Unusual or Infrequent Item, or Both [Line Items]
Nonoperating expense	3,000,000	2,900,000		8,300,000	25,300,000
Humanitarian Commitment | Selling, general and administrative expenses
Unusual or Infrequent Item, or Both [Line Items]
Nonoperating expense	600,000	1,600,000		5,300,000	13,200,000
Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	65,277,000			65,277,000		$ 70,183,000
Operating lease, right-of-use asset	9,600,000			9,600,000
Ukraine | Cost of revenues (exclusive of depreciation and amortization)
Unusual or Infrequent Item, or Both [Line Items]
Standby resources expense	0	1,000,000		9,400,000	12,900,000
Ukraine | Selling, general and administrative expenses
Unusual or Infrequent Item, or Both [Line Items]
Standby resources expense	400,000	4,400,000		900,000	37,500,000
Ukraine | Other income/(expense)
Unusual or Infrequent Item, or Both [Line Items]
Impairment charges					1,300,000
Ukraine | Humanitarian Commitment
Unusual or Infrequent Item, or Both [Line Items]
Commitments related to operating lease agreements that have not yet commenced							$ 100,000,000
Russia
Unusual or Infrequent Item, or Both [Line Items]
Impairment of property, plant and equipment			$ 15,100,000
Operating lease, impairment loss			3,800,000
Goodwill, impairment loss			$ 700,000
Bad debt expense					5,700,000
Employee separation costs		$ 700,000			$ 16,900,000
Building | Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	51,500,000			51,500,000
Computer Equipment | Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	7,600,000			7,600,000
Furniture and Fixtures | Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	4,800,000			4,800,000
Leasehold Improvements | Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	$ 1,400,000			$ 1,400,000