INCOME TAXES - Summary of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax at statutory rates	(21.00%)	(34.00%)	(34.00%)
Foreign income tax	(0.10%)	0.50%	0.70%
State income tax	(5.50%)	(5.00%)	(5.00%)
Other permanent differences	1.30%	0.40%	0.20%
Statutory tax rate change	1.20%	0.00%	(3.20%)
Statutory tax rate change - Deferred - Tax Reform Act	0.00%	(128.40%)	0.00%
Statutory tax rate change - Valuation Allowance - Tax Reform Act	0.00%	128.40%	0.00%
Compensation	0.00%	0.00%	3.00%
Goodwill impairment	0.00%	0.00%	25.20%
Refundable AMT credit	0.00%	(1.50%)	0.00%
Change in valuation allowance	25.20%	40.10%	13.50%
Effective tax rate	1.10%	0.50%	0.40%