INCOME TAXES - Components of deferred tax assets and liabilities (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for doubtful accounts	$ 2,111,000	$ 1,924,000
Accruals	465,000	2,358,000
Fixed assets	486,000	453,000
Stock-based compensation	163,000	290,000
Deferred financing costs		1,475,000
Net operating loss carryforwards	114,217,000	128,023,000
Lease liability	10,022,000	11,592,000
Interest expense carryforward	15,506,000	11,934,000
Other		(200,000)
Total deferred tax assets	142,970,000	157,849,000
Valuation allowance for deferred tax assets	(264,000)	(277,000)
Total deferred tax asset, net of valuation allowance	142,706,000	157,572,000
Deferred tax liabilities:
Intangible assets	(132,586,000)	(135,848,000)
Right of use asset	(9,232,000)	(10,336,000)
Partnership interests	(1,964,000)	(1,347,000)
Deferred financing costs	(1,196,000)
Other	(201,000)
Total deferred tax liabilities	(145,179,000)	(147,531,000)
Net deferred tax asset (liability)	$ (2,473,000)
Net deferred tax asset (liability)		$ 10,041,000