INTANGIBLE ASSETS AND GOODWILL - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill balance before cumulative loss on impairment as of January 1,	$ 1,042,762	$ 1,024,467
Accumulated loss on impairment as of January 1,	(980,547)	(980,547)
Goodwill beginning balance after cumulative loss on impairment as of January 1,	62,215	43,920
Acquisitions	20,099	18,323
Measurement period adjustments to acquired goodwill	(138)	(28)
Ending period balance	82,176	62,215
Goodwill balance before cumulative loss on impairment as of December 31,	1,062,723	1,042,762
Accumulated loss on impairment as of December 31,	$ (980,547)	$ (980,547)