INCOME TAXES - Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21.00%	21.00%	21.00%
Increase (decrease) in the tax rate resulting from:
State taxes, net of federal effect	(15.40%)	4.20%	2.40%
Foreign operations, net	19.30%	3.20%	0.70%
Research and development tax credits	(16.40%)	(1.10%)	(1.10%)
Nondeductible interest	9.90%	0.80%	0.80%
Nondeductible officers' compensation	13.60%	0.70%	0.70%
Impact of Tax Cuts and Jobs Act of 2017	0.00%	0.00%	(2.90%)
Impact of the CARES Act	(49.60%)	0.00%	0.00%
Return to provision adjustments	24.10%	(3.70%)	1.10%
Change in valuation allowance against deferred tax assets	(11.20%)	(0.30%)	0.00%
Other	(6.00%)	1.00%	2.70%
Effective tax (benefit) rate	(10.70%)	25.80%	25.40%
Tax benefit as a result of the Tax Cuts and Jobs Act			$ 1.7

Effective Income Tax Rate Reconciliation, CARES Act, Carryback of Net Operating Loss,Percent

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Effective Income Tax Rate Reconciliation, Return to Provision Adjustments, Percent

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

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