INTANGIBLE ASSETS - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Identifiable intangible assets [Abstract]
Gross Carrying Amount	$ 326,844	$ 327,330
Accumulated Amortization	238,319	232,665
Customer relationships & lists
Identifiable intangible assets [Abstract]
Gross Carrying Amount	239,194	240,059
Accumulated Amortization	$ 177,108	173,489
Customer relationships & lists | Minimum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	10 years
Customer relationships & lists | Maximum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	20 years
Trademarks & trade names
Identifiable intangible assets [Abstract]
Gross Carrying Amount	$ 42,695	43,116
Accumulated Amortization	$ 29,978	28,985
Trademarks & trade names | Minimum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	2 years
Trademarks & trade names | Maximum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	17 years
Developed technology
Identifiable intangible assets [Abstract]
Gross Carrying Amount	$ 20,184	20,234
Accumulated Amortization	$ 14,809	14,607
Developed technology | Minimum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	5 years
Developed technology | Maximum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	12 years
Other
Identifiable intangible assets [Abstract]
Gross Carrying Amount	$ 24,771	23,921
Accumulated Amortization	$ 16,424	$ 15,584
Other | Minimum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	2 years
Other | Maximum
Identifiable intangible assets [Abstract]
Amortization Period (in years)	18 years