INTANGIBLE ASSETS AND GOODWILL - Changes in Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill balance before cumulative loss on impairment as of January 1,		$ 1,062,723	$ 1,042,762
Accumulated loss on impairment as of January 1,		(980,547)	$ (980,547)
Goodwill beginning balance after cumulative loss on impairment as of January 1,	$ 82,176	62,215
Acquisitions	0	20,099
Measurement period adjustments to acquired goodwill	0	(138)
Ending period balance	$ 82,176	$ 82,176