IMPACT OF THE INVASION OF UKRAINE (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Mar. 04, 2022
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	$ 235,053,000		$ 235,053,000	$ 273,348,000	$ 236,214,000
Operating lease right-of-use assets, net	134,898,000		134,898,000	148,780,000
Commitments related to operating lease agreements that have not yet commenced	9,900,000		9,900,000
Cost of revenues (exclusive of depreciation and amortization)			3,256,514,000	3,286,683,000	2,483,697,000
Selling, general and administrative expenses			815,065,000	872,777,000	648,736,000
Impairment charges			6,019,000	23,619,000	144,000
Impairment, long-lived asset, held-for-use, statement of income or comprehensive income		Selling, general and administrative expenses
Goodwill, Impairment Loss				686,000
Bad debt expense			$ 4,047,000	12,394,000	2,488,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]			Loss on sale of business
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	37,800,000		$ 37,800,000
Nonoperating expense	17,400,000			44,800,000
Cost of revenues (exclusive of depreciation and amortization)			11,300,000	29,000,000
Selling, general and administrative expenses			6,100,000	15,800,000
Ukraine
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	62,653,000		62,653,000	70,183,000	78,289,000
Operating lease right-of-use assets, net	6,600,000		6,600,000
Ukraine | Cost of revenues (exclusive of depreciation and amortization)
Unusual or Infrequent Item, or Both [Line Items]
Standby resources expense			1,800,000	14,700,000
Ukraine | Selling, general and administrative expenses
Unusual or Infrequent Item, or Both [Line Items]
Standby resources expense			9,400,000	38,700,000
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
Ukraine | Building
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	62,700,000		62,700,000
Ukraine | Construction in Progress
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	51,500,000		51,500,000
Ukraine | Computer Equipment
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	5,900,000		5,900,000
Ukraine | Furniture and Fixtures
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	4,200,000		4,200,000
Ukraine | Leasehold Improvements
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	1,100,000		1,100,000
Russia
Unusual or Infrequent Item, or Both [Line Items]
Property and equipment, net	$ 0		0	0	$ 16,611,000
Impairment of property, plant and equipment		$ 15,100,000
Operating lease, impairment loss		3,800,000
Goodwill, Impairment Loss		$ 700,000
Bad debt expense				5,100,000
Russia | Employee Severance
Unusual or Infrequent Item, or Both [Line Items]
Employee separation costs			$ 0	$ 17,100,000