ACQUISITIONS ASSETS ACQUIRED (TABLES) (Details) - USD ($) $ in Thousands	Apr. 08, 2021	Dec. 31, 2021	Dec. 31, 2020	Nov. 04, 2020	Aug. 05, 2020	Feb. 07, 2020	Dec. 31, 2019	Oct. 26, 2019
Business Acquisition [Line Items]
Operating lease assets		$ 90,180	$ 120,820
Deferred tax assets.		51,784	57,332
Goodwill		739,481	363,502				$ 301,694
Operating lease liability - short-term		44,460	43,651
Accrued employee compensation and benefits		156,324	163,658
Operating lease liability - long-term		$ 64,419	$ 98,277
Avtex
Business Acquisition [Line Items]
Cash	$ 18,638
Accounts receivable.	22,214
Prepaid Expenses	26,389
Other assets	480
Operating lease assets	3,614
Income Taxes Receivable	93
Fixed Assets Acquired	3,162
Goodwill	378,882
Total assets acquired	587,742
Accounts payable	20,580
Operating lease liability - short-term	678
Accrued employee compensation and benefits	4,325
Accrued income taxes	332
Accrued expenses	250
Operating lease liability - long-term	2,936
Deferred tax liabilities	1,930
Deferred revenue.	56,765
Total liabilities assumed	87,796
Total purchase price	499,946
Avtex | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	5,300
Avtex | Intellectual Property [Member]
Business Acquisition [Line Items]
Intangible assets	770
Avtex | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 128,200
VoiceFoundry US
Business Acquisition [Line Items]
Accounts receivable.					$ 3,758
Prepaid Expenses					345
Goodwill					35,881
Total assets acquired					47,084
Accounts payable					289
Accrued employee compensation and benefits					741
Deferred revenue.					170
Total liabilities assumed					1,200
Total purchase price					45,884
VoiceFoundry US | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets					400
VoiceFoundry US | Noncompete Agreements [Member]
Business Acquisition [Line Items]
Intangible assets					150
VoiceFoundry US | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets					$ 6,550
VoiceFoundry ASEAN
Business Acquisition [Line Items]
Cash				$ 1,300
Accounts receivable.				937
Prepaid Expenses				115
Property, plant and equipment.				274
Income Taxes Receivable				30
Goodwill				14,418
Total assets acquired				20,474
Accounts payable				960
Accrued employee compensation and benefits				113
Deferred tax liabilities				1,013
Deferred revenue.				236
Other accrued assets liabilities, net				(78)
Total liabilities assumed				2,244
Total purchase price				18,230
VoiceFoundry ASEAN | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets				300
VoiceFoundry ASEAN | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets				$ 3,100
Serendebyte
Business Acquisition [Line Items]
Cash						$ 3,123
Accounts receivable.						1,243
Prepaid Expenses						1,327
Property, plant and equipment.						20
Deferred tax assets.						14
Goodwill						9,033
Total assets acquired						17,080
Accounts payable						120
Accrued employee compensation and benefits						1,025
Accrued income taxes						170
Accrued expenses						2,208
Deferred tax liabilities						629
Total liabilities assumed						4,152
Total purchase price						12,928
Serendebyte | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets						400
Serendebyte | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets						$ 1,920
FCR
Business Acquisition [Line Items]
Cash								$ 5,225
Accounts receivable.								10,659
Prepaid Expenses								357
Property, plant and equipment.								6,006
Other assets								224
Operating lease assets								5,127
Goodwill								96,739
Total assets acquired								171,477
Accounts payable								388
Operating lease liability - short-term								1,160
Accrued employee compensation and benefits								4,049
Accrued expenses								72
Operating lease liability - long-term								3,967
Total liabilities assumed								9,636
Total purchase price								161,841
FCR | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets								8,600
FCR | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets								$ 38,540