GOODWILL AND INTANGIBLE ASSETS - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets
Gross	$ 658,754	$ 636,307
Accumulated Amortization	(206,196)	(153,266)
Net	452,558	483,041
Technology
Intangible Assets
Gross	116,177	116,177
Accumulated Amortization	(47,570)	(38,597)
Net	$ 68,607	$ 77,580
Weighted Average Remaining Useful Life (years)	10 years 3 months 18 days	11 years
Trademark and trade names
Intangible Assets
Gross	$ 31,860	$ 31,860
Accumulated Amortization	(12,060)	(9,363)
Net	$ 19,800	$ 22,497
Weighted Average Remaining Useful Life (years)	12 years 7 months 6 days	13 years
Database
Intangible Assets
Gross	$ 6,500	$ 6,500
Accumulated Amortization	(6,500)	(6,500)
Net	$ 0	$ 0
Weighted Average Remaining Useful Life (years)	0 years	0 years
Customer relationships
Intangible Assets
Gross	$ 480,950	$ 480,950
Accumulated Amortization	(137,138)	(97,986)
Net	$ 343,812	$ 382,964
Weighted Average Remaining Useful Life (years)	9 years 8 months 12 days	10 years 7 months 6 days
Non-compete agreements
Intangible Assets
Gross	$ 820	$ 820
Accumulated Amortization	(820)	(820)
Net	$ 0	$ 0
Weighted Average Remaining Useful Life (years)	0 years	0 years
Data assets
Intangible Assets
Gross	$ 22,447
Accumulated Amortization	(2,108)
Net	$ 20,339
Weighted Average Remaining Useful Life (years)	4 years