GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Intangibles (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Other Intangible Assets [Line Items]
Cost	$ 136,616	$ 136,493
Accumulated Amortization	(129,614)	(125,605)
Net book value	7,002	10,888
Client-related
Goodwill and Other Intangible Assets [Line Items]
Cost	63,117	63,076
Accumulated Amortization	(60,035)	(58,623)
Net book value	3,082	4,453
Technology
Goodwill and Other Intangible Assets [Line Items]
Cost	68,138	68,056
Accumulated Amortization	(64,218)	(61,621)
Net book value	3,920	6,435
Other
Goodwill and Other Intangible Assets [Line Items]
Cost	5,361	5,361
Accumulated Amortization	(5,361)	(5,361)
Net book value	$ 0	$ 0
Minimum | Client-related
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	4 years	4 years
Minimum | Technology
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	2 years	2 years
Minimum | Other
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	1 year	1 year
Maximum | Client-related
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	10 years	10 years
Maximum | Technology
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	10 years	10 years
Maximum | Other
Goodwill and Other Intangible Assets [Line Items]
Useful Lives	5 years	5 years