REVENUES (Schedule of Disaggregation of Revenues) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 4,727,940	$ 4,690,540	$ 4,824,698
Revenues from performance obligations satisfied in previous period	13,600	5,800	7,500
Transferred over time
Disaggregation of Revenue [Line Items]
Revenues	4,708,622	4,674,989	4,810,148
Transferred at a point of time
Disaggregation of Revenue [Line Items]
Revenues	19,318	15,551	14,550
Time-and-material
Disaggregation of Revenue [Line Items]
Revenues	3,900,952	4,082,503	4,239,580
Fixed-price
Disaggregation of Revenue [Line Items]
Revenues	797,231	579,230	560,467
Licensing and other revenues
Disaggregation of Revenue [Line Items]
Revenues	29,757	28,807	24,651
Financial Services
Disaggregation of Revenue [Line Items]
Revenues	1,022,617	1,018,433	1,026,686
Consumer Goods, Retail & Travel
Disaggregation of Revenue [Line Items]
Revenues	1,013,138	1,072,950	1,092,224
Software & Hi-Tech
Disaggregation of Revenue [Line Items]
Revenues	702,367	707,720	793,261
Business Information & Media
Disaggregation of Revenue [Line Items]
Revenues	674,597	753,981	809,952
Life Sciences & Healthcare
Disaggregation of Revenue [Line Items]
Revenues	574,605	489,914	507,367
Emerging Verticals
Disaggregation of Revenue [Line Items]
Revenues	740,616	647,542	595,208
North America
Disaggregation of Revenue [Line Items]
Revenues	2,866,339	2,765,022	2,898,554
North America | Transferred over time
Disaggregation of Revenue [Line Items]
Revenues	2,851,319	2,751,937	2,888,342
North America | Transferred at a point of time
Disaggregation of Revenue [Line Items]
Revenues	15,020	13,085	10,212
North America | Time-and-material
Disaggregation of Revenue [Line Items]
Revenues	2,423,554	2,457,545	2,615,213
North America | Fixed-price
Disaggregation of Revenue [Line Items]
Revenues	419,361	283,183	263,603
North America | Licensing and other revenues
Disaggregation of Revenue [Line Items]
Revenues	23,424	24,294	19,738
North America | Financial Services
Disaggregation of Revenue [Line Items]
Revenues	519,986	538,837	522,970
North America | Consumer Goods, Retail & Travel
Disaggregation of Revenue [Line Items]
Revenues	450,162	472,350	505,227
North America | Software & Hi-Tech
Disaggregation of Revenue [Line Items]
Revenues	525,091	552,492	655,122
North America | Business Information & Media
Disaggregation of Revenue [Line Items]
Revenues	449,449	429,800	467,664
North America | Life Sciences & Healthcare
Disaggregation of Revenue [Line Items]
Revenues	488,455	429,245	454,102
North America | Emerging Verticals
Disaggregation of Revenue [Line Items]
Revenues	433,196	342,298	293,469
Europe
Disaggregation of Revenue [Line Items]
Revenues	1,861,601	1,909,443	1,853,056
Europe | Transferred over time
Disaggregation of Revenue [Line Items]
Revenues	1,857,303	1,907,010	1,849,011
Europe | Transferred at a point of time
Disaggregation of Revenue [Line Items]
Revenues	4,298	2,433	4,045
Europe | Time-and-material
Disaggregation of Revenue [Line Items]
Revenues	1,477,398	1,613,790	1,578,786
Europe | Fixed-price
Disaggregation of Revenue [Line Items]
Revenues	377,870	291,174	269,669
Europe | Licensing and other revenues
Disaggregation of Revenue [Line Items]
Revenues	6,333	4,479	4,601
Europe | Financial Services
Disaggregation of Revenue [Line Items]
Revenues	502,631	472,146	460,858
Europe | Consumer Goods, Retail & Travel
Disaggregation of Revenue [Line Items]
Revenues	562,976	596,830	571,437
Europe | Software & Hi-Tech
Disaggregation of Revenue [Line Items]
Revenues	177,276	153,683	136,273
Europe | Business Information & Media
Disaggregation of Revenue [Line Items]
Revenues	225,148	323,985	341,344
Europe | Life Sciences & Healthcare
Disaggregation of Revenue [Line Items]
Revenues	86,150	60,549	52,465
Europe | Emerging Verticals
Disaggregation of Revenue [Line Items]
Revenues	307,420	302,250	290,679
Russia
Disaggregation of Revenue [Line Items]
Revenues		16,075	73,088
Russia | Transferred over time
Disaggregation of Revenue [Line Items]
Revenues		16,042	72,795
Russia | Transferred at a point of time
Disaggregation of Revenue [Line Items]
Revenues		33	293
Russia | Time-and-material
Disaggregation of Revenue [Line Items]
Revenues		11,168	45,581
Russia | Fixed-price
Disaggregation of Revenue [Line Items]
Revenues		4,873	27,195
Russia | Licensing and other revenues
Disaggregation of Revenue [Line Items]
Revenues		34	312
Russia | Financial Services
Disaggregation of Revenue [Line Items]
Revenues		7,450	42,858
Russia | Consumer Goods, Retail & Travel
Disaggregation of Revenue [Line Items]
Revenues		3,770	15,560
Russia | Software & Hi-Tech
Disaggregation of Revenue [Line Items]
Revenues		1,545	1,866
Russia | Business Information & Media
Disaggregation of Revenue [Line Items]
Revenues		196	944
Russia | Life Sciences & Healthcare
Disaggregation of Revenue [Line Items]
Revenues		120	800
Russia | Emerging Verticals
Disaggregation of Revenue [Line Items]
Revenues		2,994	11,060
Americas
Disaggregation of Revenue [Line Items]
Revenues	2,834,704	2,742,662	2,887,204
Americas | North America
Disaggregation of Revenue [Line Items]
Revenues	2,726,757	2,645,174	2,792,156
Americas | Europe
Disaggregation of Revenue [Line Items]
Revenues	107,947	96,857	92,244
Americas | Russia
Disaggregation of Revenue [Line Items]
Revenues		631	2,804
EMEA
Disaggregation of Revenue [Line Items]
Revenues	1,793,198	1,822,782	1,737,919
EMEA | North America
Disaggregation of Revenue [Line Items]
Revenues	137,370	116,054	95,706
EMEA | Europe
Disaggregation of Revenue [Line Items]
Revenues	1,655,828	1,706,728	1,642,114
EMEA | Russia
Disaggregation of Revenue [Line Items]
Revenues		0	99
APAC
Disaggregation of Revenue [Line Items]
Revenues	100,038	102,138	120,370
APAC | North America
Disaggregation of Revenue [Line Items]
Revenues	2,212	3,248	3,837
APAC | Europe
Disaggregation of Revenue [Line Items]
Revenues	97,826	98,890	116,533
APAC | Russia
Disaggregation of Revenue [Line Items]
Revenues		0	0
CEE
Disaggregation of Revenue [Line Items]
Revenues	0	22,958	79,205
CEE | North America
Disaggregation of Revenue [Line Items]
Revenues	0	546	6,855
CEE | Europe
Disaggregation of Revenue [Line Items]
Revenues	$ 0	6,968	2,165
CEE | Russia
Disaggregation of Revenue [Line Items]
Revenues		$ 15,444	$ 70,185