ACQUISITIONS (Schedule of Fair Values of Net Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Nov. 03, 2021	Jul. 23, 2021	Apr. 02, 2021
Business Acquisition [Line Items]
Goodwill	$ 562,459	$ 529,072	$ 530,723
PolSource
Business Acquisition [Line Items]
Cash and cash equivalents						$ 2,565
Trade receivables and contract assets						12,734
Prepaid and other current assets						814
Goodwill						125,265
Intangible assets						15,790
Property and equipment and other noncurrent assets						461
Total assets acquired						157,629
Accounts payable, accrued expenses and other current liabilities						5,337
Short-term debt						0
Long-term debt						0
Operating lease liabilities, noncurrent						157
Other noncurrent liabilities						3,963
Total liabilities assumed						9,457
Noncontrolling interest in consolidated subsidiaries						0
Net assets acquired						$ 148,172
CORE
Business Acquisition [Line Items]
Cash and cash equivalents					$ 11,283
Trade receivables and contract assets					10,266
Prepaid and other current assets					5,430
Goodwill					24,194
Intangible assets					8,368
Property and equipment and other noncurrent assets					4,585
Total assets acquired					64,126
Accounts payable, accrued expenses and other current liabilities					9,336
Short-term debt					0
Long-term debt					0
Operating lease liabilities, noncurrent					2,056
Other noncurrent liabilities					2,525
Total liabilities assumed					13,917
Noncontrolling interest in consolidated subsidiaries					0
Net assets acquired					$ 50,209
Emakina
Business Acquisition [Line Items]
Cash and cash equivalents				$ 5,142
Trade receivables and contract assets				34,389
Prepaid and other current assets				3,109
Goodwill				139,417
Intangible assets				30,488
Property and equipment and other noncurrent assets				16,802
Total assets acquired				229,347
Accounts payable, accrued expenses and other current liabilities				37,469
Short-term debt				13,657
Long-term debt				8,874
Operating lease liabilities, noncurrent				5,541
Other noncurrent liabilities				9,319
Total liabilities assumed				74,860
Noncontrolling interest in consolidated subsidiaries				10,469
Net assets acquired				$ 144,018